Would You Move to an Exoplanet?

If given the choice where in our Milky Way galaxy you would prefer to live, where would you go? To one of those newly-discovered extra-solar planets the media get enthusiastic about when water has been detected there?

Before you answer these questions remember that, beyond the presence of water, many other conditions must be fulfilled before any planet can support the continued existence of life as-we-know-it, human life.

Over the last 40 years or so, astronomical studies have taught us that our life on Earth is dependent on a number of physical and other conditions far beyond just the presence of water. The majority of almost two hundred conditions refer to the necessary characteristics of our planet itself (temperature, chemical composition, stability, etc.) as well as to the properties of, and our location in, our Milky Way galaxy (are there nearby planets, sources of harmful radiation, etc.?).

These conditions include the following: Life on Earth requires a “just right” distance from our reliable source of energy, the sun. Earth’s chemical composition must contain those chemicals that are the main building blocks of human life: oxygen to breath, calcium to build skeletons, carbon to build carbohydrates and, together with hydrogen, nitrogen, oxygen and phosphorus, to make DNA. Earth needs a reasonably stable climate to allow food production to proceed along largely predictable lines; our Moon provides that stability for Earth’s rotation axis and its seasons. Our planet must not be too close to the centre of the Milky Way where deadly high-energy radiation would destroy life.

In fact, even the universe as a whole plays an important role in the habitability of our planet. This includes the almost perfect electrical balance between positively and negatively charged particles to ensure that the universe does not expand too fast for stars and planets to form. The word “perfect” in this sentence means an accuracy of 1 in 1037 [this is a 1 followed by 37 zeroes!]. A similar balance governs the mass density of the universe which should not vary by more than 1 in 1060; too high and the universe would have collapsed long ago, too low and the universe would expand too fast for galaxies, stars and planets to form. No wonder we talk about these specific conditions as ‘fine-tuning’!

The large number of requirements and their often narrow limits outside of which life could not exist already tell us that it may be difficult to find all of them fulfilled at a large number of different locations in the Milky Way. Add to this the fact that what we know about any extrasolar planets is still very rudimentary, and our search becomes like the one for a needle in a haystack.

Since Earth offers a successful habitat for many life forms, in a first approach we should focus on Earth-size planets in extrasolar planetary systems: the distance from their star, the presence of water, the nature of its atmosphere, etc. For each host star these conditions are only fulfilled in a fairly narrow zone around it inside of which the planet must be revolving. This zone is called the Circumstellar Habitable Zone (CHZ) of that star. It will be farther from a hotter star and closer to a cooler star (Fig. 1).

Fig. 1: CHZ (green) around three different stars; red zones are too hot, blue zones are too cold for life (courtesy NASA).

Thus, our search for suitable planets must first focus on finding suitable host stars, preferable a little less massive than the sun. Such stars are known as red dwarf stars, which constitute the overwhelming majority of stars in the Milky Way. The next step is to find small, i.e., Earth-size planets that are most likely to be rocky and have a suitable atmosphere. However, small planets are much harder to detect than their giant gaseous neighbours.

The temperature of the star and its planet’s distance from it tell us whether we can expect to find liquid water. In a few cases the planet’s atmospheric composition can be derived. Surely, before moving to any exoplanet, we want to know many more details that are not easily obtained. Therefore, even the simple question about the number of possible exoplanets fit for human life will probably not be answered today or tomorrow.

Because of the number of conditions to occur simultaneously, we do not expect to find many habitable exoplanets. The universe may turn out to be a rather inhospitable place for human life. Earth, if not unique, could well be one of a very small number of favourable planets. Considering the huge amount of fine-tuning required for a liveable planet, we should contemplate the possibility that the Creator of the universe has had a special purpose for creating Earth and its inhabitants, and that Earth’s uniqueness is a result of design rather than of accident.


Mart de Groot, PhD,  has been both an astronomer with 40 years of research experience and a pastoral minister for 16 years thereafter

Posted in Cosmology, Design | Tagged , , , , , , , | Leave a comment

What is the evidence for a large asteroid impact at the Cretaceous-Paleogene (K-Pg) boundary?

The hypothesis of a large meteorite impacting the surface of the Earth at the end of the Cretaceous was introduced almost four decades ago.[1] In the ensuing years, the geologic community gathered a large body of data in support of this hypothesis, elevating it to the status of a universally accepted fact of Earth history. However, competing models and lively discussions are still unfolding over the dynamics and environmental consequences of this large impact. This short article attempts to a) summarize the evidence that led to the acceptance of the hypothesis; b) assess current areas of uncertainty related to the impact hypothesis; and c) consider ways in which this event is relevant for creationist thinking.

History of the hypothesis and geologic evidence

Fig. 1: Physicist Luis Alvarez and his geologist son Walter, next to the thin dark clay layer (above Walter’s right hand) sandwiched between limestone beds, outcropping near Gubbio, Italy. This is one of the initial localities where the iridium anomaly was first detected. Image courtesy of Berkeley Lab (CC BY-NC-ND 2.0)

The original physical evidence that led Alvarez et al.[1] to suggest the impact hypothesis was an anomalously high content of the heavy element iridium in thin clay deposits stratigraphically placed at the so-called K-Pg boundary (Fig. 1), the contact between Cretaceous and Paleogene rocks.[2] Iridium is much more abundant in meteorites than in the rocks of Earth’s crust. Therefore, Alvarez et al.[1] concluded that all the extra iridium found in the clay boundary layer must have come from the impact of a large extraterrestrial bolide, the dust of which settled after being projected and dispersed through the Earth’s atmosphere. The theory gained strength because the iridium anomaly was detected at the K-Pg boundary in many localities around the globe, a prediction of the impact hypothesis.[3] It was also noted that K-Pg boundary clays were enriched not only in iridium but also in other noble metals more abundant in meteorites than on Earth’s crust.[4] Furthermore, numerous tiny spherules of glass and other minerals were discovered in the boundary layer and interpreted as droplets of melt and vaporized rock, ejected after the impact and solidified during fallout.[5-7] K-Pg boundary deposits were also found to contain shocked grains, which are small mineral granules showing features diagnostic of shock-induced deformation (Fig. 2). Such shock features were expected to form in crystals of target rock hit by the impactor and ejected from the crater area.[8] Finally, a surprisingly large amount of soot, a form of elemental carbon produced in the burning of flames, was also detected in some boundary clay deposits, leading to the suggestion that the impact had ignited global wildfires.[9,10]

Microphotograph of shocked quartz grain with two sets of planar deformation features (PDFs) in impact melt rock. This example comes from the Suvasvesi South impact structure, Finland. Image courtesy of Martin Schmieder (CC BY 3.0)

In their 1980 paper,[1] Alvarez et al. had already made an estimate of the size of the asteroid (~10km), predicting a diameter for the impact crater of about 200 km. However, ten years after the publication of their paper no crater structure had yet been found. It seemed that the thickness of ejecta deposits (the material expelled from the crater after the impact) decreased away from North-Central America, an area where there was also evidence of tsunami-related deposition thought to have occurred near the impact site.[11,12] Therefore, the crater had to be located somewhere between North and South America. Eventually, Hildebrand et al.[13] localized a subsurface circular structure in the Yucatán Peninsula (Mexico) of matching size, expected stratigraphic position (at the top of Cretaceous strata), and with the right type of impact-related rocks and deposits to be identified as the impact crater. This structure was given the name of Chicxulub Crater. Finding that the last missing piece of the puzzle fulfilled former predictions helped to settle the case in favor of the impact hypothesis.

Developments and open questions

Since its discovery, the Chicxulub Crater has been studied with geophysical methods and wells have been drilled to better characterize the structure and its deposits.[14-19] It appears that the crater is a multi-ring structure, with large concentric fault systems and tilted blocks around its rim, and a central uplift where deep crust and even upper mantle material was upwarped by several kilometers. Impact-related deposits include impact melt, melt-bearing breccias, and large uplifted blocks of granitic basement with pervasive evidence of shock features. The thickness of these deposits varies, but can reach up to several km within the crater. Uncertainties remain about the specific dynamics that generated the multi-ring structure during the impact, the reason for asymmetries observed in the structure, and the lithology and horizontal and vertical distribution of different impact-related deposits in the crater.

Fig. 3: An example of distal ejecta deposits. In the Agost section (Spain), the K-Pg boundary is at the base of a dark, several cm-thick, clay layer (indicated by the arrow). Photo courtesy of Dr. Raul Esperante.

The study of the ejecta deposits has also significantly advanced after the discovery of the Chicxulub Crater. Their thickness, composition, and sedimentology seem to correspond well with the location of the impact at Chicxulub.[20] Proximal deposits are thicker (from meters to hundreds of meters thick) and generally indicative of more energetic deposition, whereas distal deposits are thin (from cm to mm thick) and deposited through settling (Fig. 3). Early reports had already suggested the possibility of tsunami-related deposition caused by the impact in proximal areas.[11] However, high-quality geophysical data have revealed the truly astonishing proportions of sedimentation processes triggered by the event.[21,22] For example, in the Gulf of Mexico, a region close to the impact site, the boundary layer can be very thick (up to 400m) and is traceable all across the basin. It appears to consist of debris flows and turbidites generated by earthquakes and tsunamis, causing significant erosion and resuspension of unconsolidated sediment. Not all the sediment in this boundary deposit, considered the most voluminous event deposit known to date in the geologic record, was derived from the impact crater. A substantial component was sourced from slope instability and erosion of shelf platforms close to the impact site.

However, a dissenting interpretation of the ejecta deposits has been strongly advocated by Gerta Keller (Princeton University) and colleagues.[23-27] This alternative view suggests that some of the deposits usually interpreted as forming rapidly by sediment gravity flows related to the impact formed instead over a prolonged period of time after the impact. Therefore, they do not represent the actual K-Pg boundary. The evidence in support of this view is based on detailed sedimentological and paleontological analyses, showing a more complex picture than usually assumed. It includes the presence of distinct and multiple spherule layers, occurrence of burrowing and sedimentary structures in the boundary deposits requiring a certain amount of time to form, and erosion and reworking at the K-Pg boundary that may impede precise age attribution. If the Chicxulub Crater predates the K-Pg boundary, it could be possible that a different, subsequent impact caused the iridium anomaly, and some possibilities for multiple impact scenarios have been discussed in the literature, although they have not gained much traction.[28-30] Most importantly, if the impact precedes the K-Pg boundary by a substantial amount of time, it cannot be the direct cause for the remarkable disappearance of many groups of fossils (including the famous extinction of the dinosaurs) observed across the boundary. The link between the impact and patterns of extinctions observed in sedimentary layers spanning the K-Pg boundary has always been the most controversial aspect of the hypothesis.[3] Many paleontologists believe that the distribution of different groups of organisms in the layers below and above the K-Pg boundary was not caused by the impact, and favor more gradualistic models of extinction caused by progressive deterioration of environmental conditions, perhaps aggravated by the impact.[31] The most commonly invoked alternative as the cause for mass extinction is large scale volcanism recorded in the Deccan Large Igneous Province (India), which also spans the K-Pg boundary.[31,32]

Modelling and reconstruction of the environmental effects of the impact is also an area where considerable differences in view have emerged. The original scenario proposed by Alvarez et al. [1] of ejected dust obscuring the sky for years and shutting down photosynthesis was found to overestimate the dust load in the ejecta plume,[33] but variants of the “impact winter” hypothesis are commonly discussed in the literature.[34,35] The hypothesis of global wildfires was also reconsidered, because levels of charcoal in the boundary layer are low and soot probably derived from the ignition of organic matter in the target rocks rather than from burning forests.[36,37] Models also show that the thermal radiation caused by reentry of ejecta particles in the atmosphere was probably not sufficient to cause global wildfires.[38,39] Other suggested effects in the aftermath of the impact include acid rains and absorption of solar radiation by sulfur aerosols produced by the vaporization of sulfur-bearing sediments in the impact target rocks.[20]

Finally, an important focus of research on the impact hypothesis has been the characterization of the type of impactor, based on geochemical signatures left in the ejecta deposits, with the consensus seeming to indicate a carbonaceous chondrite.[40,41]

Implications for creationist thinking

Philosophical implications: The impact hypothesis has been instrumental in breaking the mold of gradualistic thinking in geology, spurring a new way of looking at geologic data, with renewed openness to and interest in large scale and catastrophic processes. Although this trend had already been signaled by the acceptance of Bretz’s megaflood hypothesis, the exponential growth of publications addressing catastrophes in the Earth systems[42] was certainly favored by a change in the cultural milieu where the impact hypothesis of Alvarez et al. played an important role. Creationist thinking is sympathetic to the development of catastrophic models, because a short chronology requires a great amount of geologic activity to occur over a short amount of time and because the biblical account mentions a short but globally cataclysmic flood. Therefore, creationists have benefited and will continue to benefit from the development of neocatastrophist hypotheses, with increased possibilities for common interests in research projects and collaborations with secular scholars.

Geological implications: A first consideration about the impact hypothesis is that its development and corroboration attest to the reliability of the discipline of stratigraphy. It was stratigraphy that led geochemists in their search around the world for a peak in the concentration of iridium, a peak that, in most disparate places, was where the work of stratigraphers had previously located the K-Pg boundary. This impressive example of the power and high resolution of stratigraphic correlation counters the arguments of those who are skeptical about the reliability of stratigraphy and about the value of the geologic column as a framework to spatially organize rock units.[43]

Secondly, impact-related processes and deposits are an open window to the remarkable signature of catastrophic events in the rock record and have the potential to revolutionize the gradualistic interpretive approach. In sedimentology, impact-related deposits provide an example of rapid (hours to days) basin-scale deposition of hundreds of meters of sediment.[21] and basin-scale erosion and remobilization of unconsolidated sediment.[22] In structural geology, crater formation requires extreme rock weakening, to the point of fluidization,[15] offering instructive scenarios for crust and mantle softening that could help model plate tectonic processes within a catastrophist framework. Cratering also offers an example of almost instantaneous formation of faults and tectonic features.[19] In igneous geology, models have shown that large impacts can produce massive amounts of melts almost instantaneously, leading to the suggestion that impacts might even have been responsible for the emplacement of some large igneous provinces.[44-46] At the same time, not everything in the geologic record of impacts is massive or disruptive. For example, some distal ejecta layers are only mm thin and often found sandwiched in relatively undisturbed fine grained marine deposits. Therefore, impact deposition epitomizes well the formidable complexity of the geologic record. The same event that accounts for hundreds of meters of sediment and complete disruption in one area is expressed elsewhere by a perfectly identifiable thin layer within hundreds of meters of unrelated rocks.

Finally, the physical evidence attributed to the impact is a prime example of how the rocks have a story to tell. There are indeed large shocked blocks of basement and tens of meters of breccia in the subsurface of the Yucatán Peninsula, tiny spherules forming thin layers can be found near or at the K-Pg boundary in several locations around the world, and an anomalously high concentration of iridium can be globally detected in a very precise stratigraphic interval. These observations, and many others more, can be placed together in a coherent picture.[47] in spite of all the uncertainties and limitations intrinsic to the practice of historical sciences. The reconstruction of what occurred might not be exactly right in all of its aspects, but the rocks are indeed there to challenge and alert us that something did happen.

Biblical implications: Perhaps, the most obvious question for creationists is where does the timing of the impact event fit within the framework of Earth history presented in the Scriptures. Historical narratives in the Bible do not contain a description of an impact event.[48] Consequently, we should be cautious when advocating for a specific position in the absence of explicit biblical references. The Bible does mention the global flood of Genesis as a time of major geologic activity, with the chiastic structure of Genesis 7:11 indicating the involvement of both endogenic and exogenic forces. Among the latter, signified by the “opening of the windows of heaven,” one could fit collisions of extraterrestrial objects. Indeed, in the creationist literature large meteoritic impacts on the Earth are most commonly associated with the flood event.[49-56]

Theological implications: The destructive and catastrophic nature of a large impact event has the potential to raise questions about God’s interaction with the creation and about the nature of His character. One could ask if meteoritic impacts are contingencies allowed to occur within a complex created universe or if they are a direct expression of God’s plan.

In particular, if God oversaw the unfolding of the impact event during the Genesis flood, was that accomplished through direct or secondary causation? Was there design and divine intent in the specifics of the location, energy, and timing of the impact? Answers to these questions can be placed on a spectrum between the two extremes of hyperdeterminism, where every minimal detail of geological phenomena has a predetermined purpose, and a naturalistic-like “closed system” view, where God is excluded from any further interaction with the world after the setting in motion of its laws. More significantly, one could ask how the God of love, the giver and protector of life,[57] could be so intimately associated with an utterly destructive event. In searching for answers to these difficult questions, the Genesis narrative clearly describes how the flood and its geologic processes occurred after the entrance of evil into the world and as a consequence of the total corruption of God’s original creation. The textual evidence powerfully presents the flood as the “undoing of creation.”[58] Therefore, God’s action can be seen as a withdrawal of His sustaining, ordering, and life-giving power, an expression of how things dissolve when we reject His presence. And yet, at the acme of the chiastic structure of the Genesis flood narration,[59] we are told that “God remembered Noah, and every living thing, and all the animals that were with him in the ark” (Gen 8:1). It is hard to imagine a way short of God’s miraculous protection that could preserve a human-made wood vessel and its passengers in the midst of such cataclysmic forces, of which the Chicxulub impact might have been just a small component. However, instead of taking our everyday existence as a granted necessity of nature, we should recognize behind its sustenance the same miraculous grace and mercy that carried the ark and its occupants through a perilous journey.


Ronny Nalin, PhD, Geoscience Research Institute

 

References

[1]Alvarez, L.W., et al., Extraterrestrial Cause for the Cretaceous-Tertiary Extinction. Science, 1980. 208(4448): p. 1095-1108.

[2]Originally, this stratigraphic boundary was referred to in the literature as the K-T (Cretaceous-Tertiary) boundary, a notation that was subsequently abandoned for K-Pg (Cretaceous-Paleogene), which better reflects current conventions in stratigraphic nomenclature.

[3]Alvarez, L.W., Experimental evidence that an asteroid impact led to the extinction of many species 65 million years ago. Proceedings of the National Academy of Sciences, 1983. 80(2): p. 627-642.

[4]Ganapathy, R., A Major Meteorite Impact on the Earth 65 Million Years Ago: Evidence from the Cretaceous-Tertiary Boundary Clay. Science, 1980. 209(4459): p. 921-923.

[5]Smit, J. and G. Klaver, Sanidine spherules at the Cretaceous–Tertiary boundary indicate a large impact event. Nature, 1981. 292(5818): p. 47-49.

[6]Montanari, A., et al., Spheroids at the Cretaceous-Tertiary boundary are altered impact droplets of basaltic composition. Geology, 1983. 11(11): p. 668-671.

[7]Sigurdsson, H. and S.D. Hondt, Glass from the Cretaceous/Tertiary boundary in Haiti. Nature, 1991. 349(6309): p. 482.

[8]Bohor, B.F., et al., Mineralogic evidence for an impact event at the Cretaceous-Tertiary boundary. Science, 1984. 224: p. 867-870.

[9]Wolbach, W.S., et al., Global fire at the Cretaceous-Tertiary boundary. Nature, 1988. 334(6184): p. 665-669.

[10]Wolbach, W.S., R.S. Lewis, and E. Anders, Cretaceous extinctions: evidence for wildfires and search for meteoritic material. Science, 1985. 230: p. 167-171.

[11]Bourgeois, J., et al., A tsunami deposit at the Cretaceous-Tertiary boundary in Texas. Science, 1988. 241(4865): p. 567.

[12]Hildebrand, A.R. and W.V. Boynton, Proximal Cretaceous-Tertiary boundary impact deposits in the Caribbean. Science, 1990. 248(4957): p. 843.

[13]Hildebrand, A.R., et al., Chicxulub Crater: A possible Cretaceous/Tertiary boundary impact crater on the Yucatán Peninsula, Mexico. Geology, 1991. 19(9): p. 867-871.

[14]Urrutia‐Fucugauchi, J., et al., The Chicxulub scientific drilling project (CSDP). Meteoritics & Planetary Science, 2004. 39(6): p. 787-790.

[15]Gulick, S., et al., Expedition 364 Preliminary Report: Chicxulub: Drilling the K-Pg Impact Crater. International Ocean Discovery Program, 2017.

[16]Christeson, G.L., et al., Mantle deformation beneath the Chicxulub impact crater. Earth and Planetary Science Letters, 2009. 284(1–2): p. 249-257.

[17]Morgan, J., et al., Size and morphology of the Chicxulub impact crater. Nature, 1997. 390(6659): p. 472-476.

[18]Morgan, J. and M. Warner, Chicxulub: The third dimension of a multi-ring impact basin. Geology, 1999. 27(5): p. 407-410.

[19]Gulick, S., et al., Geophysical characterization of the Chicxulub impact crater. Reviews of Geophysics, 2013. 51(1): p. 31-52.

[20]Schulte, P., et al., The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous-Paleogene Boundary. Science, 2010. 327(5970): p. 1214-1218.

[21]Sanford, J.C., J.W. Snedden, and S.P.S. Gulick, The Cretaceous-Paleogene boundary deposit in the Gulf of Mexico: Large-scale oceanic basin response to the Chicxulub impact. Journal of Geophysical Research: Solid Earth, 2016. 121(3): p. 1240-1261.

[22]Denne, R.A., et al., Massive Cretaceous-Paleogene boundary deposit, deep-water Gulf of Mexico: New evidence for widespread Chicxulub-induced slope failure. Geology, 2013. 41(9): p. 983-986.

[23]Mateo, P., et al., Mass wasting and hiatuses during the Cretaceous-Tertiary transition in the North Atlantic: Relationship to the Chicxulub impact? Palaeogeography, Palaeoclimatology, Palaeoecology, 2016. 441, Part 1: p. 96-115.

[24]Keller, G., et al., Chicxulub impact spherules in the North Atlantic and Caribbean: age constraints and Cretaceous–Tertiary boundary hiatus. Geological Magazine, 2013. 150(5): p. 885-907.

[25]Keller, G., et al., Cretaceous Extinctions: Evidence Overlooked. Science, 2010. 328(5981): p. 974-975.

[26]Keller, G., et al., Chicxulub impact predates K–T boundary: New evidence from Brazos, Texas. Earth and Planetary Science Letters, 2007. 255(3-4): p. 339-356.

[27]Keller, G., et al., Chicxulub impact predates the K-T boundary mass extinction. Proceedings of the National Academy of Sciences of the United States of America, 2004. 101(11): p. 3753-3758.

[28]Jolley, D., et al., Two large meteorite impacts at the Cretaceous-Paleogene boundary. Geology, 2010. 38(9): p. 835-838.

[29]Lerbekmo, J.F., The Chicxulub-Shiva extraterrestrial one-two killer punches to Earth 65 million years ago. Marine and Petroleum Geology, 2014. 49: p. 203-207.

[30]Archibald, J.D., et al., Cretaceous Extinctions: Multiple Causes. Science, 2010. 328(5981): p. 973-973.

[31]Courtillot, V. and F. Fluteau, Cretaceous Extinctions: The Volcanic Hypothesis. Science, 2010. 328(5981): p. 973-974.

[32]Keller, G., J. Punekar, and P. Mateo, Upheavals during the Late Maastrichtian: Volcanism, climate and faunal events preceding the end-Cretaceous mass extinction. Palaeogeography, Palaeoclimatology, Palaeoecology, 2016. 441, Part 1: p. 137-151.

[33]Pope, K.O., Impact dust not the cause of the Cretaceous-Tertiary mass extinction. Geology, 2002. 30(2): p. 99-102.

[34]Vellekoop, J., et al., Evidence for Cretaceous-Paleogene boundary bolide “impact winter” conditions from New Jersey, USA. Geology, 2016. 44(8): p. 619-622.

[35]Kaiho, K., et al., Global climate change driven by soot at the K-Pg boundary as the cause of the mass extinction. Scientific Reports, 2016. 6: p. 28427.

[36]Harvey, M.C., et al., Combustion of fossil organic matter at the Cretaceous-Paleogene (K-P) boundary. Geology, 2008. 36(5): p. 355-358.

[37]Belcher, C.M., et al., Fireball passes and nothing burns—The role of thermal radiation in the Cretaceous-Tertiary event: Evidence from the charcoal record of North America. Geology, 2003. 31(12): p. 1061-1064.

[38]Goldin, T.J. and H.J. Melosh, Self-shielding of thermal radiation by Chicxulub impact ejecta: Firestorm or fizzle? Geology, 2009. 37(12): p. 1135-1138.

[39]Morgan, J., N. Artemieva, and T. Goldin, Revisiting wildfires at the K-Pg boundary. Journal of Geophysical Research: Biogeosciences, 2013. 118(4): p. 1508-1520.

[40]Trinquier, A., J.-L. Birck, and C. Jean Allègre, The nature of the KT impactor. A 54Cr reappraisal. Earth and Planetary Science Letters, 2006. 241(3–4): p. 780-788.

[41]Goderis, S., et al., Reevaluation of siderophile element abundances and ratios across the Cretaceous–Paleogene (K–Pg) boundary: Implications for the nature of the projectile. Geochimica et Cosmochimica Acta, 2013. 120: p. 417-446.

[42]Marriner, N., C. Morhange, and S. Skrimshire, Geoscience meets the four horsemen?: Tracking the rise of neocatastrophism. Global and Planetary Change, 2010. 74(1): p. 43-48.

[43]Reed, J., P. Klevberg, and C. Froede Jr, Towards a diluvial stratigraphy, in The geologic column: Perspectives within diluvial geology, J. Reed and M.J. Oard, Editors. 2006, Creation Research Society Books. p. 31-51.

[44]Jones, A.P., et al., Impact induced melting and the development of large igneous provinces. Earth and Planetary Science Letters, 2002. 202(3): p. 551-561.

[45]Elkins-Tanton, L.T. and B.H. Hager, Giant meteoroid impacts can cause volcanism. Earth and Planetary Science Letters, 2005. 239(3–4): p. 219-232.

[46]Ingle, S. and M.F. Coffin, Impact origin for the greater Ontong Java Plateau? Earth and Planetary Science Letters, 2004. 218(1–2): p. 123-134.

[47]However, some do not find the evidence for an impact at Chicxulub convincing. See for example the recent in depth analysis by Clarey, T.L., Do the data support a large meteorite impact at Chicxulub? Answers Research Journal, 2017. 10: p. 71-88.

[48]Some of the language in Revelation 8:8-11 could be compatible with the description of the impact of extraterrestrial objects, but most modern commentators agree that the context of John’s vision is prophetic and presented in apocalyptic style. See, for example, J. Paulien, The End of Historicism? Reflections on the Adventist Approach to Biblical Apocalyptic—Part One. Journal of the Adventist Theological Society, 2003. 14(2): p. 15–43. It should also be noted that as of May 8, 2017, the Earth Impact Database  listed 190 confirmed impact structures identified on Earth, of which Chicxulub is listed as the second largest in diameter. This article focuses only on the K-Pg impact event, but biblical and theological considerations similar to those expressed for this specific event can also apply to the larger phenomenon of large meteoritic impacts on Earth.

[49]Gibson, L.J., A catastrophe with an impact. Origins, 1990. 17(1): p. 38-47.

[50]Oard, M.J., An impact Flood submodel—dealing with issues. Journal of Creation, 2012. 26(2): p. 73-81.

[51]Spencer, W.R., Geophysical effects of impacts during the Genesis Flood, in Proceedings of the Fourth International Conference on Creationism, R.E. Walsh, Editor. 1998, Creation Science Fellowship. p. 567-579.

[52]Spencer, W.R., Catastrophic impact bombardment surrounding the Genesis Flood, in Proceedings of the Fourth International Conference on Creationism: , R.E. Walsh, Editor. 1998, Creation Science Fellowship. p. 553-566.

[53]Oard, M.J., Precambrian impacts and the Genesis Flood. Journal of Creation 2014. 28(3): p. 99–105.

[54]Spencer, W.R., Impacts and Noah’s Flood—how many and other issues. Journal of Creation, 2013. 27(1): p. 85-89.

[55]Unfred, D.W., Asteroidal impacts and the Flood-judgment Creation Research Society Quarterly 1984. 21: p. 82-87.

[56]Froede, C.R.J. and D.B. DeYoung, Impact events within the young-earth Flood model. Creation Research Society Quarterly, 1996. 33: p. 23-34.

[57]See Gen.4:10,17; Gen 9:5; Ex 20:13.

[58]For a summary of scholarly work supporting the “undoing of creation” motif, see Davidson, R.M., The Genesis flood narrative: Crucial issues in the current debate. Andrews University Seminary Studies, 2004. 42(1): p. 49-77.

[59]Shea, W.H., The structure of the Genesis Flood narrative and its implications. Origins, 1979. 6(1): p. 8-29.

Posted in Catastrophism, Dinosaurs, Genesis Flood, Geological Column, Geology, Philosophical and Historical Perspectives | Tagged , , , , , , , , , , , , , , , , , , , , , | Leave a comment

Organisms in their niche: passive modeling clay or problem-solving entities?

One person’s cultural background can bias their view about people from other cultures…even before they have ever met. Could people also have a bias about how they think about other creatures? It may even be possible that scientific culture could prejudice the way researchers see creature-environmental relations with the potential to bias whole research programs.

Last November, Great Britain’s prestigious Royal Society held a conference to deliberate if evolutionary theory needed an “extension” to accommodate fresh ideas from new discoveries. Nature had also opened the question for debate (Fig. 1). Supporters of status quo evolutionary theory held that new findings could readily be explained within the current structure. While an advocate of the new “Extended Evolutionary Synthesis,” Gerd Muller of the University of Vienna had previously stated that one value of the extension would overcome the “restrictions” of “externalism.”[1] Externalism is principally a way to think about how organisms formed, yet it may bias how we think and write about a creature’s behavior. What is externalism supposed to explain for evolutionary theory and what elements of it does Muller hope to escape?

Fig. 1: Nature recognized the growing number of researchers dissenting from aspects of the Darwinian model and opened a discussion in 2014. Laland, K. et al. 2014. Does evolutionary theory need a rethink? Nature. 514 (7521):161-164.

As it turns out, disputes over whether the source of an organism’s form derives from external or internal causes have been longstanding. Stephen Jay Gould frames this historical discussion: “The designation of one principle or the other [internalism/structuralism or externalism/functionalism] as the causal foundation of biology virtually defines the position of any scientist towards the organic world and its causes of order. Shall we regard the plan of high-level taxonomic form as primary, with local adaptations viewed as a set of minor wrinkles (often confusing) upon an abstract majesty? Or do local adaptations build the entire system from the bottom up?…This dichotomy continues to define a major issue in modern evolutionary debates: does functional adaptation or structural constraint maintain priority in setting evolutionary pathways and directions?”[2]

In this case, the phenomenon most in need of explanation is: why do organisms appear to fit their environments so well? They have traits that seem to precisely relate to, and even exploit properties of nature (e.g., inertia and gravity) and other external conditions. Externalists, see these traits as imposed on organisms from the outside. This generally happens by the very external conditions, designated as “selective pressures,” which match so well to the trait. Michael Denton explains that according to the paradigm “often referred to as functionalism, the main designs of life (pentadactyl limb, body plans, etc.) are not the result of physical law, that is, not immanent in nature or arising from intrinsic physical constraints inherent in biological matter, but rather the result of specific adaptations built additively by selection during the course of evolution, to serve particular functional ends, ends that are imposed by the environment and that are external to the organism itself.”[3]

Few people recognize that in the externalist approach organisms are viewed essentially as passive lumps of clay being molded by their environment. In fact, two researchers stated that is exactly how Charles Darwin’s theory encapsulates the organism-environment relationship, “He [Darwin] accepted the view that the environment directly instructs the organism how to vary, and he proposed a mechanism for inheriting those changes…The organism was like modeling clay, and remolding of the clay meant that each of the billions of little grains was free to move a little bit in any direction to generate new form…If an organism needed a wing, an opposable thumb, longer legs, webbed feet, or placental development, any of these would emerge under the proper selective conditions with time.”[4] Which Marta Linde Medina, another leading theoretician in this field, sums up, “as a result, organisms are as passive as the matter that forms them.”[5]

Externalism has a strong philosophical appeal to those who advocate for explanations of biological phenomena that are fully naturalistic. It is certainly not teleological. Externalism also can feed into the view that if God didn’t create nature, nature can somehow create itself—including crafting living things. Interestingly, externalism is analogously central to both Darwin’s theory of evolution and influential psychologist B.F. Skinner’s theory of human behavior. “First, both theories draw on an externalist or ‘outside-in’ pattern of explanation, in which the structure or behaviour of living things is seen as a consequence of their environments. Second, both rely on a process that can be described loosely as ‘trial and error.’”[6]

Externalism is currently the dominant view in biology. Denton elaborates on the probability that any view other than externalism would be “very alien” and essentially “inconceivable to most English-speaking biologists.”[7] But what if it is wrong in the sense that it has identified causality backwards? This updated insight may be indicated by waves of discoveries documented by Gerd Muller and others. They’ve found a principal role for internal factors.

What if populations of organisms could be seen from a design-based perspective as traveling through diverse environments just as human-designed vehicles do? Designed capacity of an entity is always an internal feature as designers build into their craft the ability to successfully engage all anticipated external conditions. Similarly, innate self-adjusting capacity should be true for organisms. Thus, intrinsic design could control both its basic body plan and 100% of its ability to adapt itself to external conditions. Internal programming also specifies certain external conditions to be a stimulus or a cue for both man-made things and organisms. Inherently designed systems control detection of challenging exposures and would specify internally driven self-adjustments primarily as targeted solutions to environmental challenges and rarely, if ever, by “trial-and-error.” Individuals (or populations over multiple generations) could actively detect environmental conditions and could express a spectrum of phenotypes from a relatively stable genotype controlled by innate systems.

Enriching the phenotypic panoply is the capacity of several biological systems to “learn” from environmental interactions by processes similar to IBM’s “Watson” computing system; meaning, organisms are designed with a nature already devised to be nurtured. It may be demonstrated that organisms are causal for the successful fit of their traits-to-exposures, rather than externalism’s notion of personified environments seeing, selecting, and saving traits to build organisms.

Perhaps, the tight organism-environment relationship may be explained by populations of active, problem-solving organisms continuously tracking environmental changes via innate mechanisms to express heritable phenotypes bearing problem solving potential—which already precede environmental challenges. This is worth thinking about as an internalist approach may well be confirmed by continuing research.


Randy J. Guliuzza, P.E., M.D. is a licensed professional engineer and medical doctor previously Board Certified in Aerospace Medicine who now specializes in researching engineering principles of biological adaptation.

 

References

[1]Muller, G. B. and M. Pigliucci. 2010. Evolution—The Extended Synthesis. Cambridge, Mass.: The MIT Press, p. 13.

[2]Gould, S. J. 2002. The Structure of Evolutionary Theory. Cambridge, Mass.: Harvard University Press, p. 252.

[3]Denton, M. J. 2013. The Types: A Persistent Structuralist Challenge to Darwinian Pan-Selectionism. BIO-Complexity, (3):1−18. doi:10.5048/BIO-C.2013.3

[4]Kirschner, M. and J. Gerhart. 2005. The Plausibility of Life. New Haven: Yale University Press, p. 3. 31.

[5]Linde Medina. M. 2011. Reply to the Comments on “Natural Selection and Self-Organization: A Deep Dichotomy in the Study of Organic Form.” Ludus Vitalis 19 (36):387-397.

[6]Godfrey-Smith, P. 2010. It Got Eaten. London Review of Books. 32 (13):29-30. http://www.lrb.co.uk/v32/n13/peter-godfrey-smith/it-got-eaten

[7]Denton, M. Two Views of Biology: Structuralism vs. Functionalism. Posted on evolutionnews.org February 3, 2016 accessed on March 28, 2017. https://www.evolutionnews.org/2016/02/two_views_of_bi/

Posted in Biology, Design, Environment, Evolutionary Theory, Philosophical and Historical Perspectives | Tagged , , , , , , , , , | Leave a comment

A Review of the Documentary Film “Is Genesis History?”

Is Genesis History? asks a question that many Christians struggle with. Is the first book of the Bible comprised of pious myths? Is it an allegory designed to teach important lessons about God, but not actually a record of the history of life on Earth? Or is it a reliable record of events that actually occurred in the past? In other words, is Genesis the oldest book of history available today, one that records events that really did occur in the ancient past, or is it and the information it contains something else?

Dr. Art Chadwick of Southwestern Adventist University discusses dinosaur fossils with Is Genesis History? host Del Tackett.

Dr. Art Chadwick of Southwestern Adventist University discusses dinosaur fossils with Is Genesis History? host Del Tackett.

In addressing whether or not Genesis is history, host Del Tackett of Focus on the Family takes viewers to a number of spectacular locations. At each of these, he interviews an expert who explains the significance of what is being viewed. Paul Nelson comes across very well in a museum of computing and Marcus Ross in a museum full of dinosaurs and other fossils. Art Chadwick’s segment out at the spectacular dinosaur site he and his team are excavating is impressive, and who wouldn’t be interested in what Steve Austin has to point out in the Grand Canyon? The way in which the film takes viewers to places and exposes them to some of the abundant scientific research makes this a fascinating and compelling film. I count a total of 11 expert scientists ranging from microbiologist Kevin Anderson to astronomer Dany Falkner, but Hebraist Steve Boyd and Pastor George Grant add a dimension that rounds out the film in an interesting way. It turns out that the humanities play a role as important as the sciences in addressing questions about Genesis.

This doesn’t mean that every possible line of evidence is explored, the focus of the film is on history, geology and time, but there is so much data and so many questions that covering everything is more than the work of a lifetime. While some wise restraint is shown, if I had one criticism, it would be that Is Genesis History? still probably tries to cover a bit too much ground in too little time. At least this keeps it moving along at a brisk pace and gives a general overview of some of the science that is consistent with the Genesis account, as well as theological arguments and commentary on the original Hebrew.

Most Young Earth Creationists will probably love Is Genesis History?. It is a good general introduction to some of the evidence consistent with events like the flood and the understanding of origins shared by Bible-believers. Those who do not share that belief, but are willing to take this film as an education in what others are thinking will be better off for watching it. On the other hand, zealous deniers of the Genesis record of history will find it maddening. Is Genesis History? will inevitably get lots of 1 and 5 star reviews if it is ever sold on Amazon.com.

Probably the most valuable thing about Is Genesis History? is that it makes quite clear to any viewer that there are serious scientists and scholars who are willing to engage with and, in fact, embrace the biblical account of history and the data from nature. In addition, a significant amount of that data they engage with is consistent with and well interpreted within a biblical paradigm. In other words, believers are not fanatics who believe based on blind faith. There are reasonable empirical reasons to believe that Genesis really is a record of history and, in general, the interpretations that come out of this paradigm are quite rational.

Is Genesis History? avoids advocacy of controversial models that seem improbable when you think about them. If I give examples, I risk many long and pointless discussions with those who believe some of them actually do make sense, so I’ll avoid that. Watching a film about the creation in which it is not necessary to occasionally wince as some improbable speculation is trotted out as both true and supported by the Bible is wonderful.

Finally, the way Is Genesis History? is being released is interesting. It will be screened for one night, February 23, 2017, in several hundred theaters across the US. This is being done through an organization called “Fathom Events.” How effective will this be? Only time will tell, but my expectation is that it will get a lot of church groups into theaters that night. Christians should not be embarrassed to take a Christian group to see it, or a friend who is interested, but not a believer. The production quality is pretty good; it moves along at a stimulating pace and Del Tackett is an engaging host who draws out the expertise of the 13 experts featured in the film. I’ll be going to watch it and expect I will be in some very good company.


Epilog – February 24, 2017

These are my reactions after watching Is Genesis History? at the Regal Riverside Plaza Stadium 16 theater in Riverside. Please note that I’m writing from memory, so there may be some minor errors in my recall of details, but my objective is to report major impressions rather than give an exhaustive and detailed critique.

My reaction falls into two categories: 1) the actual experience of the event and 2) my take on the final cut. I will begin with the experience itself, but to do that I should first mention something that occurred shortly before the showing. This was a posting by Paul Nelson repudiating what he said in the film. It can be found at:

http://www.evolutionnews.org/2017/02/new-film-is-genesis-history-presents-a-false-dichotomy-i-dissent-from-my-role-in-it/

This sounds far worse than it actually is, but Paul’s concern about the way he comes across in the film is valid. For a detailed explanation, read what Paul has to say. Paul is concerned that he placed the fundamental dichotomy between evolution and long time periods versus creation and short time periods, which is wrong place. He feels—and I’m sympathetic to this view—that the true dichotomy revolves around the philosophy of naturalism. If methodological naturalism is embraced as the rule for scientific knowledge, we come to an interpretation of nature which generally includes evolution and long time periods. If we reject naturalism, we head in the direction of theism which may or may not involve creation over long or short time periods. It is unusual for the premiere of a film to coincide with a critique by one of those involved of their own performance, but I personally think this is fantastic. It reflects incredibly positively on those who worked on Is Genesis History?. These are not people who are offering simplistic explanations rooted in traditional interpretations. Paul shows an admirable concern for what is true and a willingness to evaluate what they have done and correct misconceptions. I am in deep admiration of the courage and humility it took to do this. In addition, I believe that Paul’s repudiation brings a level of clarity that we seldom see in discussions of origins.

After procrastinating for way too long, when I went to purchase my ticket online for Is Genesis History?, I was both surprised and pleased to see that the screen where I was to watch it was almost sold out. This meant reserving a seat near the end of the very front row. After I purchased my ticket, there were about 8 seats left. When I arrived to see the film, I was surprised to see that it was being shown on a second screen in the multiplex theater, but have no idea if this was added in response to the fact that the first screen sold out. What was interesting was seeing the number of people who just looked like Christians in the lobby. In fact, I ran into one or two people I know who were there to see the film. Looking at what was showing on the other screens in the theater, the juxtaposition of Fifty Shades Darker with Is Genesis History? was interesting. If nothing else, showing Is Genesis History? in this particular multiplex meant that two of its screens were showing something of actual interest and with the potential to edify viewers.

As expected, when I took my front row seat to watch Is Genesis History?, there were not many empty seats. In fact, in this 76-seat room, I counted 3 empty seats, but I’m not sure about the few handicapped seats that were available. Certainly, there were less than 10 empty seats, but I have no idea how many there were at the other screen in the same theater. The crowd itself seemed to be excited about what was going on, with different snippets of conversation revealing, unsurprisingly, a large proportion of evangelical Christians. The gentleman seated next to me attends The Grove Community Church in Riverside. Strangely, while there was nothing on the screen and the lights were turned down, there was some audio running that sounded as if it belonged with video. At exactly 7:00 pm, the scheduled start time, anticipation was clearly high, but nothing actually happened. Eventually, what sounded like an opening series of ads for other films began, but there was still no image on the screen. This prompted some joking and murmuring among the audience. Further technical difficulties marred the start of the program. Eventually, there was video, but no audio and finally, with a bit of an audience cheer, we had both. However, we were still subjected to a long series of promotions for different wonderful looking programs and extra materials associated with Is Genesis History? Then, a short film was shown detailing who the experts featured in the film are.

While I think everyone was more than ready to get into the film at this point, showing this short about the authors before the feature film did address one objection raised before the showing, that viewers could have the misimpression that Steve Boyde, an expert in Hebrew, was associated with Hebrew Union College, where his interview was filmed. While Dr. Boyde has a Ph.D. in Hebraic and Cognate Studies from Hebrew Union College, both the short and website for Is Genesis History? make it clear that he does not work there. I believe this misimpression arose from the fact that in the film itself the lower thirds consistently give both the name of the person being interviewed and the place where the interview took place. So “Steve Austin” and “Grand Canyon” appear together and the pattern repeats with the other experts. So, while Dr. Boyde does have some legitimate association with Hebrew Union College, the lower third was simply revealing the location of the interview.

The film itself didn’t start until 7:30 pm, half an hour after the scheduled start time. Some of this may have been due to the initial technical difficulties, but irrespective of that, my personal feeling was that the amount of material before starting was excessive and detracted from the experience. It may be that some of it was shown to cover for the technical problems, but I have no real way of knowing. What was clear was that there was some degree of relief among the audience when the actual main feature started and we could sit back to enjoy it in our special reclining theater seats.

I will get to a short critique of the final cut of Is Genesis History? in a moment, but want to mention that at the end of the feature, there was an interview by the host, Del Tackett, of three of the experts featured in the film: Andrew Snelling, Danny Faulkner and Robert Carter. When the film ended by fading to a quotation of Romans 1:20, there was a smattering of applause among the audience, but this petered out when the film went straight into the interview. Many in the audience had clearly enjoyed the film, but were ready to leave, so the interview was a bridge too far. During it some started to leave. This was a pity as the interview did a lot to flesh out some important points, like the fact that not all creationists agree on all interpretations of the evidence. When the end finally came, it was after the scheduled ending time of 9:00 pm, suggesting that the technical issues at the start drove the timing of everything back by several minutes.

So how would I summarize the overall experience? For me it was pretty wonderful. Being with other believers is always a joy and Is Genesis History? really is an interesting film to watch. Yes, there were some technical difficulties and these probably made the experience seem to drag on a little too long at the end, but overall it was great.

As far as the final cut of Is Genesis History? is concerned, this is a good film and my overall impression remains consistent with my initial review of an earlier cut. Del Tackett’s opening at Mt. St. Hellens is very cleverly done. His interviewing style is great and he does the very difficult job of bringing experts in various fields to the point in a reasonably succinct way. That is not a trivial achievement!

What about Paul Nelson’s repudiation of what he says on the film? I continue to admire Paul for what he did. As a philosopher, he is clearly seeking for the greatest precision and clarity in the important point he is making. Having said that, I’m fairly sure that more casual viewers will not be troubled by what is actually on the film.

The few films that I have personally worked on do not make me an expert on every aspect of film production, but there were a few production issues that did jump out at me. While most of the audio is excellent, there is wind noise in a couple of short segments. The most distracting noise comes during one part of the interview with Art Chadwick where tarpaulins flapping in the wind make a significant racket. Audio is something that anyone producing a film has struggled with and maybe perfection is too much to expect, but those few short segments were distracting for me. The editing is well done and keeps the pace of the film comfortable while constantly moving forward. If there was one change I’d make, it would be to comb through and remove every possible occurrence of the word “absolutely.” Editing audio to remove words can be tricky, but for some reason the word “absolutely” pops up absolutely too many times. In general, the videography is excellent. The way drone shots were used, particularly toward the beginning and end, is spectacular and the impact was greatly enhanced on the big theater screen. At the same time, much of what was filmed occurred in bright sunlight casting harsh shadows. There were many shots that would have been enhanced by using a reflector to brighten the speakers faces, or shooting earlier or later in the day when the lighting is a bit softer and more complimentary. This is particularly true of times when the speakers were wearing hats casting a dark shadow across their face. I wish the director had talked Del Tackett into removing his cap when he was talking out in the field. Finally, I’m not sure whether this was an issue with the camera used or something else, but both in Is Genesis History? and the interview that followed, dark areas on the screen were quite pixelated in some shots. There are a number of reasons this can happen, some of which may be fixable, but whatever the reason, it is a shame to see this sort of thing in a film. While these are minor quibbles and don’t detract from the content of the film, they may not even be visible on smaller screens, it is a pity to see them.

In summary, I’m glad that I joined the thousands of other viewers who attended the rollout of Is Genesis History?. The experience was great and the film itself is well worth seeing, whether or not you agree with everything that is said. If you are interested in seeing Is Genesis History? yourself, the place to watch for additional showings and announcements about DVDs or web streaming is the film’s website at:

http://isgenesishistory.com/

Is Genesis History? was the top film in theaters within the United States on February 23, 2017. It may be tempting to sniff at this, after all, it was a Thursday night, not a weekend, when theater audiences peak. Having said that, over 143,000 people attended, and that is nothing to sniff at. Additional showings have been scheduled, mostly in the same theaters, for Thursday, March 2 and Tuesday, March 7.


Review by Timothy G. Standish, PhD
Senior Scientist
Geoscience Research Institute

Posted in Reviews and Events | Tagged , , , , , , , | 5 Comments

Microbes, Symbiosis, and the Lesson of Interdependence

A very common reaction to the thought of “microbes” is a compelling desire to slather up in hand sanitizer! However, it is seldom realized that the greatest majority of microorganisms are at the very least not harmful, and at the most necessary for human life! Many aspects of microbial interaction with our environment allow it to be so perfect for humans. Some of these aspects include oxygen generation, nitrogen fixation, decomposition, food-chain contributions, food production, and antibiotic production. However, in this blog I want to highlight one specific aspect of the contribution that microbes make to our lives and our environment by focusing on symbiotic relationships.

A symbiotic relationship is one in which at least one partner must be in the relationship in order to survive. We know now that symbiotic relationships between microbes and other organisms are common, and are proving to be more of the rule of life than the exception.

  1. A popular example of symbiosis is the relationship that corals have with algal cells living within them (Fig. 1).The algal cell within the coral photosynthesizes providing metabolic products for the coral to consume, and the coral offers a safe living environment for the alga. When corals become stressed, they often expel the algal cells, causing “bleaching,” and usually soon after die. Corals are the builders of the oceans; constructing reefs that provide safety and an environment for thousands of other organisms to live and thrive.

    Fig. 1: SEM Microphotography of the endodermal tissue of the polyp of a reef coral (Porites porites) that shows the distribution and density of symbiont algal cells (genus Symbiodinium, indicated by the arrows). Photo courtesy of Allisonmlewis, available at https://en.wikipedia.org/wiki/Symbiodinium#/media/File:HostTissue_section.png (CC BY-SA 4.0).

    Fig. 1: SEM Microphotography of the endodermal tissue of the polyp of a reef coral (Porites porites) that shows the distribution and density of symbiont algal cells (genus Symbiodinium, indicated by the arrows). Photo courtesy of Allisonmlewis, available at wikipedia.org (CC BY-SA 4.0).

  2. Lichens are another example of symbiosis involving microorganisms. Lichens typically grow on rocks or the bark of trees and are a symbiosis of algal or cyanobacterial cells living within a fungal matrix of hyphae (long, hair-like fungal cells). Together these organisms form what we know as lichens that are not only beautiful, but form an important part of the food chain for other organisms.
  3. Even more widespread and important, is the symbiosis of bacteria in the guts of all plant-consuming animals. Animals and humans lack the ability to metabolize plants because they can’t digest cellulose, a polymer of glucose that makes up the woody (fibrous) parts of all plants. This glucose is linked together in a fashion that prevents our enzymes from breaking it apart. Nevertheless, cellulose is the main source of carbon and energy for many animals that live on grass, straw, and, in the winters, eat bark right off the trunks of trees. These animals are able to survive on cellulose because they have bacterial symbionts in their guts that convert it into various fats, which can then be digested and consumed for nutrition. I imagine when God spoke the plants and animals into existence and gave them the “herbs of the field to eat,”(Gen 1:30) that He also, in the same breath, created a system of symbiosis where every animal was constantly dependent on something unseen to provide nutrients – an important spiritual lesson of our dependence on God for our daily bread, not only to nourish our physical bodies, but to sustain our spiritual being.
  4. New studies of symbiosis in humans reveal that the bacteria in our guts profoundly impact our health: our microbiome affects obesity, diabetes, autoimmune diseases, and mental disorders. Scientists are discovering that the foods we eat not only affect our own health, but the health and variety of our microbiome, which then, in turn, affects our health. Some microbes in our intestines produce vitamin K, a vital nutrient. Researchers now know that human exposure to microbes causes an improvement of their immunity and decreases allergies like hay-fever. Symptoms of some deadly allergies like lupus and rheumatoid arthritis can even be reduced by introduction of microbe infections such as worms. The number of microorganisms in our body is equal to the number of our own cells, however due to their microscopic size we outweigh them!  I believe that when God formed humans he built into us a symbiotic relationship with microorganisms that is part of who we are and aids in the functioning of our bodies. Once again, a spiritual lesson for God’s quiet, but constant help as we make our way through this world.
  5. A final example of a symbiotic relationship is that between soil microbes and plants. Of the vascular plants researched, 95% were found to be associated with mycorrhizae, which are fungi that associate with roots of plants. Additionally, some types of bacteria, referred to as rhizobia, live within the roots of legume plants (such as soybeans, alfalfa, and peanuts) in specialized structures called root nodules where the bacteria provide nitrogen to the plant, and the plant supplies the bacteria with simple sugars (Fig. 2).

    Rhizobia nodules on the roots of a cowpea (Vigna unguiculata) plant. Photo courtesy of Dave Whitinger, available at https://en.wikipedia.org (CC BY-SA 3.0)

    Rhizobia nodules on the roots of a cowpea (Vigna unguiculata) plant. Photo courtesy of Dave Whitinger, available at wikipedia.org (CC BY-SA 3.0)

Our world is interdependent. God created us to be in association with each other. This is not only seen among humans, but in other created organisms as well. We admit that sin has had an effect on all of creation, and the Darwinian competition and struggle for survival might be an expression of this. However, cooperation and positive interaction between organisms, even of different species, is also an important narrative in biology. One lesson we can glean from this look into the natural world of microorganisms and symbiosis is that we are happiest and healthiest when we are living our lives in service to one another.


Suzanne Phillips, Ph.D., is the chair of the Department of Earth and Biological Sciences, Loma Linda University

Posted in Anatomy and Physiology, Biology, Cooperation, Design, Environment | Tagged , , , , , , , , , | 1 Comment

The Great Search

The Geoscience Research Institute is located on the campus of Loma Linda University Health, an institution of higher learning that keeps Christian service at the core of its mission. In this post, we asked Dr. Richard Hart, the President of Loma Linda University Health, to share some personal reflections on the role of knowledge in the quest for meaning and greater understanding. 


In a world drowning in information, there is an even stronger search for ultimate truth. It seems the information age expects each of us to sort out misleading advertisements, internet “facts”, and professionally perpetrated misinformation in our own attempts to determine what is true. Even our recent presidential election and continuing political dialogue centers on the issue of what is really true.

For those of us who feel that knowing truth and having confidence in our belief is not only important, but possible, this great search for truth is both concerning and even prophetic. This becomes even more evident when working in an academic health science institution like Loma Linda, where Biblical truths and scientific advances are both considered essential foundations of knowledge. So how do we tread this line in a world that is now fully captivated by the logic and power of the scientific method and its interpretation of the world around us?

As someone who learned the basics of medicine over 45 years ago, it is clear that many of the “facts” of yesteryear are now debunked and a new set of “facts” has taken their place. Many diseases that had obvious explanations when I was a student are now shown to be something quite different in causation and treatment. Does this mean we are closer to the truth today than before? Or are we just taking our understanding to a different level, only to learn more in the future?

I can apply the same concerns to the Biblical “truths” I was taught as a child. Growing up in rural northern Idaho, life was simple and it seemed the difference between right and wrong was clear. But exposure to the broader world has changed my views on many issues, including race relations, gender issues, addictions, Sabbath observance, impact of genetics, origins, and perhaps most importantly the human and even individual imperfections that influence our church teachings and doctrines. I can see different ways to interpret Biblical concepts that seemed so clear in one direction as a child, but are now more complex and nuanced. Does that mean I am straying from the “truth” or am I reaching a new level of understanding of God’s ideal for mankind?

Coming back to Loma Linda, are there instructions – research boundaries – we should be insisting our faculty adopt and follow? Or are we brave enough to let truth take us where it will, believing that our God is the ultimate arbiter? There is a fascinating debate recorded in our board minutes from the 1950’s when two professors, Richard Walden and Frank Lemon, first proposed studying the causes of death among Adventists in California, comparing them to American Cancer Society controls. Their proposal prompted a big debate – what if we weren’t healthier, if our unusual health practices were not beneficial? Fortunately the board gambled on Walden and Lemon, and their study became the foundation of the Adventist Health Studies that have now gained such acclaim for the benefits of the Adventist lifestyle. I certainly hope that today we do not fear this great search for truth, believing that the One who created us also knows all about our science and Bible and where it must eventually lead.

So where does this leave us? Surely there are some absolutes that are unquestionable? Yes, I am sure there are, in both the Bible and science. But I am also convinced that we must continue to embrace a certain skepticism, a wondering in our souls, about many questions that are before us today. God has given us individually the power to think and question, to wonder and make decisions. Our church pioneers labored long and hard to filter out the essentials that established this church, but also taught the concept of “present trutharth”, the idea that better understandings will come in the future. I am comfortable with that status, even though it leaves a certain uneasiness inside. My sense is that this is exactly the way God wants it, keeping me asking while still believing, having faith before the unknown, wondering while also certain of His care and guidance.


 

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Stability of Organic Molecules: Lessons from Vitamin C

The  stability of organic (carbon-based) molecules is an interesting and challenging topic as there are many different types of functional groups, molecular configurations, and molecular collisions to consider.  Research on the stability of ascorbic acid (Vitamin C) and other vitamins demonstrates which factors to consider when it comes to the preservation of carbon-based molecules.   Ascorbic acid is a very important but very unstable organic molecule which is characteristic of the class of organic molecules we know as vitamins (Fig. 1).

Figure 1: Ascorbic Acid better known as Vitamin C is an unstable organic molecule that is highly water soluble.

Figure 1: Ascorbic Acid, better known as Vitamin C, is an unstable organic molecule that is highly water soluble.

Vitamin stability has been studied for decades under a variety of storage conditions, and it is interesting to see how chemical manufacturers address long term stability issues. As stated on the website of DSM  (a chemical company located in the Netherlands): “The vitamin manufacturing industry has developed products of high purity and quality, with improved stability, high bioavailability and optimum handling and mixing properties…. However, when dealing with complex and reactive compounds such as the vitamins, no product form can offer complete and unlimited protection against destructive conditions, excessive periods of storage or severe manufacturing processes. The individual feed manufacturer must take responsibility for assuring customers that vitamins have been stored, handled and added to feeds in an optimum manner and that vitamin levels are routinely monitored for quality assurance.”

Temperature, water content, pH, oxygen levels, light (type/intensity), catalysts (metals like Fe, Cu, etc), inhibitors, chemical interactions, energy (heat), and time are all factors that affect the stability of organic molecules. Double bonds and other functional groups are susceptible to rearrangements and reactions that vary with these conditions and is why organic chemistry textbooks are so thick! Vitamin C is somewhat stable in a dry, powdered form but dilution in water greatly accelerates the transformation of ascorbic acid into a biologically unusable form.   Low pH’s can slow this degradation but at neutral to higher pH, dilute solutions of vitamin C can degrade very quickly. Every organic molecule has its  own conditions of stability. In general, UV-light and oxygen are constantly attacking these molecules and rearranging their structures into molecular configurations unsuitable for their original purpose.   Water speeds the degradation. This is why many vitamins and pharmaceuticals are packaged in thick, dark containers with desiccants.

Eliminating water, oxygen, and energetic radiation (gamma, x-ray, UV, visible) can greatly extend and preserve organic molecules which is why some biomolecules can be preserved for longer periods of time when embedded in crystalline or amorphous solids like amber or stone. Scientists have tried to mimic natural means to preserve biochemical molecules through the use of sugars like trehalose. Trehalose can help enzymes and proteins preserve their activity when lyophilized (freeze-dried) together. Other sugars and polyols have been explored as a partner chemical that provides many hydrogen bonding sites that stabilize the complex 3-D structure of proteins, enzymes, and nucleic acids in the absence of water but trehalose seems to be one of the best.

Water Bears (tardigrades) (Fig. 2) have been in the news lately because new information about their genome relating to their ability to survive harsh conditions such as absolute zero, vacuum of space, and high temperatures around volcanoes was recently published.

Scanning electron microscopy images of the extremotolerant tardigrade, Ramazzottius varieornatus, in the hydrated condition (a) and in the dehydrated state (b), which is resistant to various physical extremes. Scale bars, 100 μm. From Hashimoto et al., 2016, Nature Communications, 7, 12808 (Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License).

Scanning electron microscopy images of the extremotolerant tardigrade, Ramazzottius varieornatus, in the hydrated condition (a) and in the dehydrated state (b), which is resistant to various physical extremes. Scale bars, 100 μm. From Hashimoto et al., 2016, Nature Communications, 7, 12808 (Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License).

The November 7, 2016 issue of Chemical & Engineering News featured this recent research as it interests chemists and engineers who are trying to find innovative ways to preserve unstable carbon-based molecules of life: “Although commonly found in moss and lichens, tardigrades are truly aquatic animals, requiring a film of water surrounding their body to take in oxygen and expel carbon dioxide. Without water, they dry out, practically cease metabolism, and curl up into a sturdy desiccated form called a tun. It is the tun state that enables tardigrades to withstand many extremes. And then if they return to water, they bounce right back.”   It is believed that tardigrades produce various “dry-tolerant proteins” that “are intrinsically disordered in water but develop secondary structures in the dehydrated state that allow them to stabilize DNA, proteins, and cell membranes.”

Carbon-based chemistry in living systems is  constantly under thermodynamic and kinetic distress from heat, light, radiation, oxygen, water and other reactive chemicals that limits their longevity. This is to say nothing of the enzymatic biological attacks from the microbial world that slice-and-dice organic chemicals in an effort recycle them for their own energetic requirements.   The same flexibility that allows living systems to constantly recycle and renew carbon-based materials are the same mechanisms that inhibit long term stability.


Ryan T. Hayes is a Ph.D. chemist (Andrews University) studying how to preserve vitamin C and other biomolecules through the use of spherical nanopolymers called dendrimers.

 

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