Category Archives: Science

Evolution 101, with reference to coronavirus

By T. Ryan Gregory. Reproduced with permission

Mutations occur as chance errors in replication. They’re just mistakes in copying. Most have no effect. Some are detrimental to the organism (or virus), a few may happen to be beneficial — this depends on the environment.

Three main evolutionary processes determine what happens to genetic variation once it arises (and these are independent of the process that generates new variation, namely mutation): genetic drift, natural selection, and gene flow.

We call different versions of a gene “alleles” and we can talk about the proportion of those versions in a population as “allele frequencies”. Genetic drift is a random change in allele frequencies that occurs by chance.

Genetic drift is basically sampling error, in which the genetic variation in a new generation does not accurately reflect what was present in the previous generation. The most obvious mechanisms of genetic drift are founder effects and population bottlenecks. (But see below about genetic drift being common in small populations generally). Founder effects occur when a random, non-representative subset of a population moves to a new location and founds a new population. The allele frequencies in that founder population won’t be the same as in the source population, and there will typically be less variation overall.

Population bottlenecks are sudden, severe declines in population size in which survival happens at random. So, for example, a drought or storm causes a major die-off and the individuals who survive were just lucky (rather than having traits that helped them survive).

Gene flow is movement of genetic variation from one population to another. The overall effect is to introduce new variation into an existing population (if the source population has different alleles) and to make two populations that exchange alleles more similar to each other.

When we think about the early stages of new species evolving, we generally are considering ways that gene flow is being blocked. Lots of gene flow means two populations are less likely to diverge genetically.

The final evolutionary mechanism is natural selection. In this case, the reason some individuals survive and reproduce better than others is *non-random*. It doesn’t occur by chance. It is specifically related to heritable traits that make survival and reproduction more likely.

This is where the concept of “fitness” is relevant. In evolutionary terms, fitness refers to the advantage in survival and/or reproduction due to heritable traits. Fitness depends on the environment. What is fit in one environment may be neutral or unfit in another environment.

There are different forms of natural selection, depending on what part of the distribution of traits is fit/unfit in the population: directional selection, diversifying (or disruptive) selection, and stabilizing selection.

Under directional selection, one extreme of the distribution is fit and the other is unfit. This drives the distribution of traits in a particular direction from one generation to the next.

For example, if the largest individuals leave more offspring on average than smaller individuals in each generation, then the average size will increase over time. Not because individuals start being born larger in response, but because more offspring are born of large parents.

In diversifying selection, it is the two extremes that are fit and the average traits that are unfit. This can cause a population to split into two. For example, if the smallest and largest individuals do well but the medium-sized are at a disadvantage.

Finally, in stabilizing selection the average value is fit and the extremes are both unfit. The result is that this prevents the distribution of traits from changing in the population because deviations from the current average are detrimental in that environment.

I have added an image from Wikipedia to show these three types of natural selection. A is the original distribution of traits, B is the new distribution. 1) Directional, 2) Stabilizing, 3) Diversifying selection.

The different types of genetic selection: on each graph, the x-axis variable is the type of phenotypic trait and the y-axis variable is the amount of organisms. Group A is the original population and Group B is the population after selection. Graph 1 shows directional selection, in which a single extreme phenotype is favored. Graph 2 depicts stabilizing selection, where the intermediate phenotype is favored over the extreme traits. Graph 3 shows disruptive selection, in which the extreme phenotypes are favored over the intermediate. From Wikipedia

There are many factors that affect these evolutionary mechanisms. Mutation rates can be high if there is weak quality control and repair of errors, or if there is some environmental factor (mutagen) that messes up replication.

It also matters how much replication is happening. Every time a genome is replicated, there can be errors. Lots of replication means lots of opportunities for mistakes to occur. (In multicellular organisms, only mutations in the germline are relevant in evolution, of course).

As to what happens to alleles, this depends on the environment as well as population size. Genetic drift, which is sampling error, is stronger when samples (i.e., populations) are smaller. Natural selection, which is non-random, is stronger when populations are large.

Whether an allele is fit or unfit (will be subject to non-random natural selection) or neutral (will evolve by random genetic drift) depends on the environment.

Natural selection and genetic drift can happen at multiple levels. The main one is, of course, among organisms within populations, but these can also happen within organisms. Cancer is an example of cell-level selection that is usually suppressed in multicellular organisms.

When it comes to viruses, there are two levels as well: within hosts and among hosts. Because viruses mutate so quickly (by chance, because their repair mechanisms are weak), there can be new variation arising within a single host.

Some mutants will do better within the host — that is, they will be better at invading host cells or will be replicated more quickly than other versions of the virus within a host.

So, there is natural selection within the host.Some mutants will do better at getting into new hosts. For example, maybe they form smaller aerosol particles and spread father when sneezed out. Or maybe they are in high concentration in the nose rather than deeper in the lungs, so they get shed more easily.

The mutant viruses that do best within a host are not necessarily the same ones that do better at infecting new hosts. In fact, a highly virulent version might be very effective at invading host cells but do so much damage that the host never spreads it to another host.

There can be a trade-off between virulence (replication within a host that causes damage to the host) and transmissibility (spread to new hosts). Which versions of a virus evolve depends on the mutations that happen to occur by chance replication errors and the outcome of genetic drift and natural selection both within hosts and among hosts.

Whether viral evolution involves increased or decreased virulence and/or higher or lower transmissibility depends on many factors. Number of replication events happening. Rates of replication errors. Selective pressures within and among hosts. Viral and host population sizes.

Virulence and transmissibility are not the same thing, and there may be trade-offs between them, but it’s also a concern that a virulent (damages or kills the host) virus can still be successful at the host population level if it is able to spread to many new hosts.

Viruses that are both highly virulent and transmissible will eventually run out of hosts to infect, but they can do great damage before that happens.

One of the many positive effects of reducing transmission (e.g., with vaccines, masks, etc.) is that this imposes a selection pressure for less virulence. If only versions of the virus that don’t incapacitate or kill the host manage to reach new hosts, then those are fitter. Reduced transmission also means fewer replication events happening and this means fewer new mutations.

A mild but highly transmissible version of a virus can spread quickly through a population and then fizzle out as hosts become immune, and many people seem to be assuming this will happen with Omicron, but that also means a lot of replication and new mutations.

The Omicron variant in particular has many, many mutations specifically in the spike protein, which is one reason it is so much more transmissible and escapes previous immunity. And this may now be the starting point for new variants.

It is possible that Omicron is milder (than Delta, at least) and that it will infect pretty much everyone and that this will be a step toward SARS-CoV-2 becoming endemic (like flu, requiring seasonal vaccinations).

But it is also possible that Omicron may undergo more chance mutations that make it more virulent as well as highly transmissible. Then it spreading rapidly will mean many hospitalizations and deaths before it runs out of hosts. We do know it is still evolving.

Viruses don’t want anything. They just spread to new hosts or they don’t, and replicate effectively in hosts or they don’t. Mutation, genetic drift, gene flow, natural selection. There are many factors we can’t control, but there are some that we can. We really ought to try.

No photo description available.
Molecular phylogeny of Covid-19 variants. From https://nextstrain.org/ncov/ via T.Ryan Gregory’s posting

Tall el-Hammam; an airburst of gullibility; it gets worse

I shared the excitement when I read at https://www.nature.com/articles/s41598-021-97778-3 that

in ~ 1650 BCE (~ 3600 years ago), a cosmic airburst destroyed Tall el-Hammam, a Middle-Bronze-Age city in the southern Jordan Valley northeast of the Dead Sea

File:Tall el-Hammam overlooking the Jordan Valley 2007.jpg
Tall el-Hammam, overlooking Jordan Valley. Dead Sea and Jerico beyond it on horizon, to left. Creative Commons via Wikipedia

and that this event could have given rise to the biblical account of the destruction of Sodom and Gomorrah. Then I learned that the work was conducted by a group based on an unaccredited Bible college (Trinity Southwestern University, TSU), that the world’s leading authority on airbursts has denounced the claims as impossible, that eight separate major research groups have questioned the assumptions, reproducibility, and factual accuracy of related earlier work by the corresponding author, that there is an unusually active thread criticisng the work on PubPeer, and that Retraction Watch, which says that criticism has engulfed the paper, is in correspondence with the Chief Editor of the journal, part of the Nature group, where the work appeared.

Figure 53
Boslough’s supercomputer 15-megaton model of the Tunguska airburst, as copied in the paper under discussion

Problems listed by acknowledged experts in PubPeer include misuse of Mark Boslough‘s account of airbursts (Boslough is a long-standing critic of the claims of the TSU group); and no clear evidence that the destrution of the palace walls was catastrophic, absence of qualified examination of skeletons, anatomically misdescribed bones, claims without evidence that bone damage was associated with traumatic death, rather than later damage, the mixing of kinds of debris is commonplace and not evidence of catastrophe, the connection of the carbon-14 dates to the alleged destruction is not established, and claims of burning of bone lack evidence and consistency (Megan Perry of the Petra North Ridge Project, who knows what this kind of stuff looks like.) There is undeclared image manipulation, eventually admitted, but described as without significance. And the account of diamond vs graphite in the paper

Each diamonoid typically contains carbon atoms that are sp3-bonded (i.e., 3 bonded carbon atoms), as in diamond, rather than with sp2 bonding (i.e., 2 bonded carbon atoms), typical of graphite

does not inspire conidence.

Figure 44c fromthe paper. Note direction of shadows and of direction pointer

In the paper’s Figure 44c, shadows are cast by a sun shining from the direction labelled North. This obviously cannot happen at Tall el-Hammam, giving rise to further concerns about the quality of the work.

My own browsing in what are for me odd places1 shows that other archaeologists, including Aren Maeir of Bar Ilan University, agree in finding nothing unusual in the report compared to “normal” destruction by fire or warfare) Maeir is quite explicit:

[T]he destruction the report described was not that unusual. “I see some things that remind me of phenomena that we have in the Iron Age IIA (1000–925 BC) destruction at Tell es-Safi/Gath (e.g. vitrified or “melted” bricks, ultra-high temperatures, and other things)—a destruction that is most likely caused by the conquest and destruction of the site by Hazael of Aram,” he said.

Mark Boslough, an expert on cataclysmic events who even has an asteroid named after him, tells me that he is tired of repeated rebuttal of what he considers to be obviously false claims, and of seeing his own theoretical analysis of the effect of airbursts invoked as an explanation of claims completely inconsistent with such a process, or perhaps any credible process. For this reason, rather than publishing yet another counterblast that will be ignored, he has taken to describing the controversy, extending over many years, on Twitter (see here, here, and subsequent threads, and PubPeer).

Phillip Silvia, the author from whom soil samples can be obtained, is an electrical engineer by training, who received his PhD training in archaeology at TSU, and published much of this material through TSU press in 2016 as a paperback, in which his PhD advisor, Steven Collins, strangely absent from the author list of this paper although not from an earlier abstract, states (Foreword, page x) that “the Genesis 19 description of Sodom’s destruction was about good a phenomenological description of a cosmic airburst as one could imagine” and describes Tall el-Hammam as “the site I had identified as Sodom based on geographical details embedded in the boblical text”.

Screenshot from Collins’ introduction to Silvia’s 2016 book

Like I suspect many of the journalists and interested readers who swooped on this story, I failed at first to notice that the paper was not, despite the link, an article in Nature but in Scientific Reports. This is one of the stable of less exclusive journals closely linked to Nature being published by Springer, now controlled by the publishing giant Hotlzbrinck, and profiting from Nature’s reputation for excellence. I was only vaguely aware of the authors’ long history of invoking airbursts, took the many kinds of evidence listed at face value, and did not even blink at the claim that “[a]n airburst-related influx of salt (~ 4 wt.%) [from the Dead Sea, apparently] produced hypersalinity”.

Temperature changes in the central region of Greenland’s ice sheet.From US Geological Survey

The authors have since described this work to a much larger audience in The Conversation, where they repeat their claim, also published in Scientific Reports, of a similar catastrophe at Abu Hureyra in what is now Syria, around 10,800 BCE, assert that “it almost certainly won’t be the last time a human city meets this fate”, claim that such events “pose a severe modern-day hazard”, and advise that “unless orbiting or ground-based telescopes detect these rogue objects, the world may have no warning, just like the people of Tall el-Hammam.” The Abu Hureya paper also repeats a litany of earlier claims that the Younger Dryas, a period of severe cold in the northern hemisphere from around 12,900 to 11,700  years Before Present [Present is fixed at 1950 CE],  was caused by a  series of impacts with cometary debris, spread over at least four continents. These claims have been severely disputed; see papers listed below.

There are numerous additional reasons for concern about the TSU researh group.

Image
Trinity Soutwestern University campus, aerial view

The paper tells us that “The project is under the aegis of the School of Archaeology, Veritas International University, Santa Ana, CA, and the College of Archaeology, Trinity Southwest University, Albuquerque, NM, under the auspices of the Department of Antiquities of the Hashemite Kingdom of Jordan.” Veritas International University believes in “the full historicity and comprehensibility of the biblical record”. It is accredited by the Transnational Association of Christian Colleges and Schools (TRACS), which I have discussed here before. Trinity Southwest University, which now operates from an office in a strip mall in Albuquerque, was formerly in Tulsa, Oklahoma, under the name Southwest Biblical Seminary, and rejects any government accreditation whatsoever as intrusive violation of the separation of Church and State. While the traditional site of Sodom is in Israel (and within the pre-1967 boundaries).

The corresponding author is Allen West, who has been publishing prolifically in this area since 2005 (Evidence for the Extinction of Mammoths by an Extraterrestrial Impact Event) and in 2006 co-authored a book, The Cycle of Cosmic Catastrophes: How a Stone-Age Comet Changed the Course of World Culture, which claims  that the debris of a shattered comet was responsible for  “a cosmic chain of events [that] began 41,000 years ago and culminated in a major global  catastrophe  28,000 years later.” These events include everything from the extinction of the mammoths to the landform of the Carolina Bays to the legend of Atlantis to a purported “mysterious layer of black sediment” found spanning North America to the Younger Dryas discussed in the Abu Hureya paper.  West has no academic qualifications or affiliations, and gives his address as Comet Research Group (CRG), Prescott, Arizona (several of the other authors are also members of this group, which is linked to the Rising Light Group, a 501(c)3, tax-exempt charitable organization with a clear Christian and biblical agenda, registered in Allen West’s name.). As detailed by Pacific Standard Magazine, discussing how thing stood regarding CRG’s work in 2017, there have been calls for a for a formal inquiry and

University of Wyoming archaeologist Todd Surovell and his colleagues couldn’t find increased magnetic spherules representing cosmic debris at seven Clovis sites. Nicholas Pinter and his colleagues at Southern Illinois University Carbondale argue the carbon spherules are organic residue of fungus or arthropod excrement. And Tyrone Daulton of Washington University in St. Louis and his colleagues reported that supposed nanodiamonds formed by the impact were misidentified.

On the other hand, in an acrimonious exchange with me in the Comments section of The Conversation, West pointed out that

Our group included, among many others: Dr. James Kennett, emeritus professor at UCSB, specializing in stratigraphy, micropaleontology, paleobiology. He is a member of the National Academy of Sciences, which recognizes the contributions of just 0.1% of all scientists. Dr. Ted Bunch, former NASA section chief and a world-leading meteoriticist. Dr. Robert Hermes, retired from Los Alamos National Labs, world-recognized expert in trinitite or atomic glass. Dr. Wendy Wolbach, chemistry professor who discovered high-temperature soot at the K-Pg boundary.

I replied with a listing of some papers that I have examined criticising West’s own earlier work regarding airbursts, including sampling techniques and claimed evidence for very high temperatures:

Scott AC, Hardiman M, Pinter N, Anderson RS, Daulton TL, Ejarque A, Finch P, Carter-champion A (2017). “Interpreting palaeofire evidence from fluvial sediments: a case study from Santa Rosa Island, California, with implications for the Younger Dryas Impact Hypothesis”. Journal of Quaternary Science. 32 (1): 35–47. doi:10.1002/jqs.2914.

*Boslough M, Harris AW, Chapman C, Morrison D (November 2013). “Younger Dryas impact model confuses comet facts, defies airburst physics”. Proceedings of the National Academy of Sciences of the United States of America. 110 (45): E4170. doi:10.1073/pnas.1313495110.

*Boslough M (April 2013). “Faulty protocols yield contaminated samples, unconfirmed results”. Proceedings of the National Academy of Sciences of the United States of America. 110 (18): E1651. doi:10.1073/pnas.1220567110

Van Hoesel A, Hoek WZ, Pennock GM, Drury MR (2014). “The Younger Dryas impact hypothesis: a critical review”. Quaternary Science Reviews. 83: 95–114. doi:10.1016/j.quascirev.2013.10.033.

*Meltzer DJ, Holliday VT, Cannon MD, Miller DS (May 2014). “Chronological evidence fails to support claim of an isochronous widespread layer of cosmic impact indicators dated to 12,800 years ago”. Proceedings of the National Academy of Sciences of the United States of America. 111 (21): E2162-71. doi:10.1073/pnas.1401150111.

*Holliday VT (December 2015). “Problematic dating of claimed Younger Dryas boundary impact proxies”. Proceedings of the National Academy of Sciences of the United States of America. 112 (49): E6721. doi:10.1073/pnas.1518945112.

Thy P, Willcox G, Barfod GH, Fuller DQ (2015). “Anthropogenic origin of siliceous scoria droplets from Pleistocene and Holocene archaeological sites in northern Syria”. Journal of Archaeological Science. 54: 193–209. doi:10.1016/j.jas.2014.11.027.

*Van der Hammen T, Van Geel B (2016). “Charcoal in soils of the Allerød-Younger Dryas transition were the result of natural fires and not necessarily the effect of an extra-terrestrial impact”. Netherlands Journal of Geosciences. 87 (4): 359–361. doi:10.1016/j.jas.2014.11.027

See, however, in defence of the Younger Dryas impact theory, *Sweatman MB (2021). The Younger Dryas Impact hypothesis: Review of the impact evidence. Earth-Science Reviews. 218: 103677. doi:10.1016/j.earscirev.2021.103677. I thank Christopher R. Moore, one of the authors of the paper I am criticising, for drawing my attention to this review.

*Freely accessible via doi; for other papers, doi gives access to abstracts but not full text.

We await further developments with interest.

1] Bit for a rebuttal by a biblical archaeologist involved in the dig, though not an author on this paper, see here

An earlier edition of this post appeared on pandasthumb.org

Why creationism bears all the hallmarks of a conspiracy theory

A friend asked me why I bother about creationism. This article spells out my reasons. It has had some 150,000 reads since first published in The Conversation in February, and has been featured in Snopes and Yahoo! News, and attacked by Ken Ham and Bodie Hodge of Answers in Genesis, Jake Hebert Ph.D [sic] at the Institute for Creation Research, and others.

https://images.theconversation.com/files/381349/original/file-20210129-21-zsa3bk.jpg?ixlib=rb-1.1.0&rect=0%2C374%2C4031%2C2015&q=45&auto=format&w=1356&h=668&fit=crop
A replica of Noah’s Ark from the biblical tale at the Ark Encounter theme park in Kentucky. Lindasj22/Shutterstock

Many people around the world looked on aghast as they witnessed the harm done by conspiracy theories such as QAnon and the myth of the stolen US election that led to the attack on the US Capitol Building on January 6. Yet while these ideas will no doubt fade in time, there is arguably a much more enduring conspiracy theory that also pervades America in the form of young Earth creationism. And it’s one that we cannot ignore because it is dangerously opposed to science.

In the US today, up to 40% of adults agree with the young Earth creationist claim that all humans are descended from Adam and Eve within the past 10,000 years. They also believe that living creatures are the result of “special creation” rather than evolution and shared ancestry. And that Noah’s flood was worldwide and responsible for the sediments in the geologic column (layers of rock built up over millions of years), such as those exposed in the Grand Canyon.

Book cover of The Genesis Flood, The Biblical Flood and its Scientific Implications.

Such beliefs derive from the doctrine of biblical infallibility, long accepted as integral to the faith of numerous evangelical and Baptist churches throughout the world, including the Free Church of Scotland. But I would argue that the present-day creationist movement is a fully fledged conspiracy theory. It meets all the criteria, offering a complete parallel universe with its own organisations and rules of evidence, and claims that the scientific establishment promoting evolution is an arrogant and morally corrupt elite.

This so-called elite supposedly conspires to monopolise academic employment and research grants. Its alleged objective is to deny divine authority, and the ultimate beneficiary and prime mover is Satan.

Creationism re-emerged in this form in reaction to the mid-20th century emphasis on science education. Its key text is the long-time best seller, The Genesis Flood, by John C Whitcomb and Henry M Morris. This provided the inspiration for Morris’s own Institute for Creation Research, and for its offshoots, Answers in Genesis and Creation Ministries International. [Note added: Ken Ham points out in his rebuttal that Answers in Genesis arose independently of the Institute for Creation Research, and that his article concerning denial of divine authority, cited in the previous paragraph and below, does not mention Satan by name.]

Ken Ham, the founder and chief executive of Answers in Genesis, is also responsible for the highly lucrative Ark Encounter theme park and Creation Museum in Kentucky. As a visit to any of these websites will show, their creationism is completely hostile to science, while paradoxically claiming to be scientific.

Demonising and discrediting

These are common conspiracy theory tactics at play. Creationists go to great lengths to demonise the proponents of evolution, and to undermine the overwhelming evidence in its favour.

There are numerous organisations, among them Biologos, the American Scientific Affiliation, the Faraday Institute, and the Clergy Letter Project, which describes themselves as “an endeavour designed to demonstrate that religion and science can be compatible”, that is, promoting evolution science within the context of religious belief. Even so, creationists insist on linking together the separate topics of evolution, materialist philosophy, and the promotion of atheism.

According to Answers in Genesis, evolution science is a work of Satan, while former US Congressman Paul Broun has described it as “a lie straight from the pit of hell”. When he said that, by the way, he was a member of the House of Representatives Committee on Science, Space, and Technology.

Like other conspiracy theorists, creationists immunise themselves from fact-based criticism. They label the study of the past as based on unprovable assumptions, thus disqualifying in advance the plain evidence of geology.

They then attack other evidence by focusing on specific frauds, such as Piltdown man – a hoax skeleton purportedly of a missing link between humans and other apes that was debunked more than 60 years ago – or the dinosaur-bird amalgam “Archaeoraptor”, discredited by sharp-eyed scientists before ever making it into the peer-reviewed literature (although not before making it into National Geographic).

One favourite target is Ernst Haeckel, whose pictures of embryos, published in 1874, are now considered to be seriously inaccurate. However, they do correctly draw attention to what most matters here: the features shared during development by different organisms – including humans – such as gill arches, a long tail, and eyes on the side rather than the front of the head, confirming they have a common ancestry.

Haeckel’s name appears on the Answers in Genesis website 92 times. He is also the subject of a lengthy chapter in Jonathan Wells’ Icons of Evolution; Science or Myth?. This book, which even has its own high school study guide, was what first convinced me, back in 2013, that creationism was a conspiracy theory.

More from The Conversation’s Expert guide to conspiracy theories here.

It is a splendid example of creationist tactics, using long-rectified shortcomings (such as those in early studies on Darwinian evolution in peppered moths, in response to changing colours following reduced pollution) to imply that the entire science is fraudulent. Wells has a real PhD in biology, a PhD acquired with the specific goal of “destroying Darwinism” – meaning evolution science – from the inside.

Wells is a senior fellow at the Discovery Institute, a conservative thinktank which promotes creationism under the banner of “Intelligent Design”, and is also linked to other conspiracy theories, such as claims that the consensus on climate change is bogus, and that last November’s US presidential election was stolen. An article by a senior fellow at the Discovery Institute on the subject has now being removed from its website, but can be found here.

A series of graphics indicating seven contributing parts of a conspiracy theory.
How those fighting science denial break down reasoning of conspiracy theories. JohnCook@skepticalscience, Author provided

What next?

Conspiracy theories are always driven by some underlying concern or agenda. The theory that Obama’s birth certificate was a forgery, or that the 2020 US election was stolen, are about political legitimacy and will fade as the politicians promoting them fade from memory. The idea that COVID-19 does not exist is proving a little harder to dislodge, but scientists, such as those behind Respectful Insolence, are organising to fight back on science denial and misinformation.

I fear that the creationist conspiracy theory will not be so short-lived. It is driven by a deep-seated power struggle within religious communities, between modernists and literalists; between those who regard scripture as coming to us through human authors, however inspired, and those who regard it as a perfect supernatural revelation. And that is a struggle that will be with us for a long time to come.

‘God intended it as a disposable planet’: meet the US pastor preaching climate change denial

Grace Community Church Worship.jpg
Service at Grace Community Church. Lukasinia own work via Wikipedia

Every so often you come across a piece of writing so extraordinary that you cannot help but share it. One such piece is a sermon on global warming by American pastor John MacArthur. Full of beautifully constructed rhetorical flourishes, it is forcefully delivered by an experienced and impassioned preacher to a large and appreciative audience.

For me, as a man of science, it is the most complete compilation of unsound arguments, factual errors and misleading analogies as I have seen in discussions of this subject. But it’s important because climate change is a big election issue this November in the US, where there is a growing movement of evangelical Christians who deny its existence, while Joe Biden promises a “clean air revolution”.


Read more: Faith and politics mix to drive evangelical Christians’ climate change denial


The minister of the COVID-denying, law-defying Grace Community Church in Sun Valley, California – which has encouraged worshippers to congregate as normal despite state COVID-19 restrictions – MacArthur is an impressive figure whose Study Bible has sold almost 2 million copies.

He regards the infallibility of the Bible, from Genesis to Revelation, as essential to his faith, and his sermon about global warming can only be understood in that context. MacArthur’s rejection of the science is shared by other major US ministries and organisations such as Answers in Genesis, Creation Ministries International and the Discovery Institute.

In this sermon, MacArthur paraphrases “a scientist at Cal Tech” (except not a scientist at all, but the novelist Michael Crichton, best known for Jurassic Park), as saying in a lecture:

Consensus science is the first refuge of scoundrels … invoked only in situations where there is a political, social, financial agenda but no scientific support.

The reverend has the most serious reasons possible for rejecting the scientific consensus concerning the age of the Earth, the origins of humankind, the history and prehistory of the ancient near East and the peopling of continents: it is totally incompatible with the Genesis account of creation, Adam and Eve, the flood and the dispersion of peoples from the Tower of Babel.

Error, denial and misunderstanding

As for global warming itself, the reverend channels standard climate change denial, but all his arguments are unsound and have been convincingly refuted to the satisfaction of an overwhelming consensus of climate scientists (see in-depth discussion at Skeptical Science). He understates the amount of global warming, incorrectly describes the full record as dating back only 30 years, and cites the Little Ice Age as evidence that the changes currently taking place are natural. There’s more:

Here’s the key, friends, this is the real deal. Legitimate science recognises a close correlation between sunspots and climate change … The sun is the source of temperature changes because of its infrared variations. … There is absolutely no evidence that CO₂ contributes to warming. On the contrary the opposite is true. Warming produces CO₂ … It’s the other way round.

Here we have a collection of half-truths and misunderstandings, typical of denialists claiming to represent “legitimate science”. As the graph below shows, the 11-year sunspot cycle is a minor deviation, and the temperature increase since 1980 has occurred despite the fact that over that period the amount of solar energy falling on Earth has gone down slightly. Incidentally, this solar energy input is concentrated mainly in the visible, not the infrared, region of the spectrum, and it is the roughly balancing heat outflow from the Earth that is in the infrared.

Graph showing global temperature change between 1980 and 2015
NASA, Author provided

MacArthur offers a false dichotomy between saying that CO₂ warms the oceans, and warmer oceans release more CO₂. Unfortunately, both these statements are true. There is a positive feedback loop: human-released CO₂ is the primary driver, but its effect is amplified by the fact that yet more CO₂ is then released from non-human sources. Regarding CO₂ itself, MacArthur seems to be even more confused:

By the way, plants produce CO₂. What man produces is marginal … Industry doesn’t affect CO₂ in the environment or atmosphere.

Plants do produce CO₂ but they absorb more than they emit. However, when it comes to humans, their activity may cause only a small imbalance each year between CO₂ emission and natural uptake, but this imbalance is cumulative. CO₂ levels are now 50% above pre-industrial, and subtle atomic differences clearly show that fossil fuel is the source. But according to MacArthur, “There is no scientific reason to believe that ice caps are melting”.

Despite the Arctic Monitoring and Assement Programme’s video on this subject, the reverend does not think that the evidence for ice-cap melting is scientific, and that other factors are at play:

This is all political [and] financial agendas, class warfare, class envy … By the way, US$100 billion has been spent to make a case for global warming … driven by the socialist mentality … even some of the feminist mentality that resents male success.

All is now clear. Talk of global warming is part of a politically motivated conspiracy. But US$100 billion? That’s 600 years’ worth of all federal climate research spending. Clearly, those pesky socialists and feminists are formidable fundraisers. However, none of this matters because environmentalism is fundamentally misplaced. As MacArthur puts it, citing Revelation and the integrity of scripture:

God intended us to use this planet, to fill this planet for the benefit of man. Never was it intended to be a permanent planet. It is a disposable planet. Christians ought to know that.

And that is a statement that would leave anybody who cares about this world speechless.

This piece first appeared in The Conversation, where it has had over 300,000 reads. I thank my editor there, Jane Wright, for many helpful suggestions.

Undark: In Social Insects, Researchers Find Hints for Controlling Disease

Repost from UndarK:

In Social Insects, Researchers Find Hints for Controlling Disease

July 22, 2020 by Michael Schulson

Given that she infects ant colonies with deadly pathogens and then studies how they respond, one might say that Nathalie Stroeymeyt, a senior lecturer in the school of biological sciences at the University of Bristol in the U.K., specializes in miniature pandemics. The tables turned on her, however, in March: Covid-19 swept through Britain, and Stroeymeyt was shut out of her ant epidemiology lab. The high-performance computers she uses to track ant behavior sat idle, and only a lab technician — deemed an essential worker — was permitted to tend to the lab’s hundreds of black garden ant colonies, each housed in its own plastic tub.

With governments across the world now encouraging people to maintain space between one another to prevent the spread of the virus, Stroeymeyt drew parallels with her insect subjects. The current guidance on social distancing “rung familiar,” Stroeymeyt said, “because I’ve been seeing it among the ants.”

Such insights are at the heart of a burgeoning field of insect research that some scientists say could help humans imagine a more pandemic-resilient society. As with humans, fending off Read the rest of this entry

What does Mt St Helens teach us about Noah’s flood? Almost nothing.

CanyonGoogleEarthYoung Earth Creationists (YECs) argue from the rapid and dramatic events observed at the Mt St Helens 1980 eruption to the conclusion that the Earth’s geological record, as displayed for example at the Grand Canyon, could be the results of the even more dramatic events associated with a biblical worldwide flood. Geochristian, in the post I link to below, dismantles specific examples of this claim, and goes on to challenge the view that the Bible describes Noah’s Flood as a worldwide catastrophe anyway. Illustration: Step Canyon, Mt St Helens; Google Earth via Geochristian

Regarding geology, the YEC arguments derive their rhetorical power from the all-or-nothing thinking that runs through all their positions. They claim that Mt St Helens demonstrates the correctness of catastrophism over geological gradualism. If all this much can happen so quickly, why assume that the Earth’s deep geology really required deep time? If the flowing ash and mud from Mt St Helen’s shows lamination and cross bedding, does that not destroy the geologist’s argument that the lamination and cross bedding of shales and sandstones are the result of slow deposition? If in a matter of days snowmelt carved a canyon in the Mt St Helens deposits, would not the waters of a year-long flood have sufficed to carve out the Grand Canyon? If the Mt St Helens eruption rapidly uprooted and re-deposited large number of trees, could not the Earth’s fossil fuel deposits have been formed in the same manner?

Geochristian discusses each of these claims in detail (spoiler; none of them will stand up to examination). What I want to point out here is how much they all have in common. They all depend on imposing absolute either/or divisions on reality, cherry picking similarities and ignoring differences, and imposing the simplest of models on complex reality. The dispute between catastrophism and gradualism, although repeatedly revived by creationists (see e.g. here https://www.allaboutcreation.org/catastrophism-versus-uniformitarianism-faq.htm ) was pronounced dead by TH Huxley, “Darwin’s bulldog”,in his Presidential Address to the Geological Society in 1869 https://mathcs.clarku.edu/huxley/SM3/GeoAd69.html. It’s simply a matter of perspective. Catastrophic events do happen from time to time, but not very often, giving the impression of gradualism over long periods of time. Cross bedding can occur catastrophically, in well-understood special circumstances, but geologists have never had any difficulty in distinguishing between what is found in sudden volcanic outpourings and the completely different wind-blown cross bedding observed in desert sandstones, including ironically the Coconino Sandstone within the Grand Canyon itself. Canyons such as Mt St Helens Step Canyon can indeed form very rapidly in uncompacted sediments, but the Step Canyon is straight, and carved on a steep slope through soft debris, while Grand Canyon has bends and is carved through extremely hard rock by a river flowing over a plateau with, overall, a gentle gradient. And the tree debris from Mt St Helens bears no resemblance, either in texture or in amount, to the world’s coal fields.

Next, Geochristian attacks the YEC interpretation of Genesis. In particular, the word “eretz”, describing the territory immersed in the flood, can mean either the Earth, or a more limited region. Here his motivation is to preserve faith in the text, while rebutting the interpretation that requires the flood to be worldwide. My own approach would be rather different. In the biblical narrative, God sets out to destroy mankind, apart from the virtuous relic represented by Noah and his family. This could hardly have been accomplished by a merely local flood, though one could well argue that the author(s) of Genesis did not make a clear mental distinction between local and worldwide. However, the entire problem disappears if you regard the Genesis narrative (or, rather, fused narratives) in context within a much more ancient Mesopotamian literature, and I argue https://paulbraterman.wordpress.com/2018/11/12/noahs-flood-and-how-to-talk-to-creationists-about-it/ that this is actually more respectful of the text than supernaturalist literalism. However, in my experience discussions between those who do, and those who do not accept a supernatural origin for Scripture are rarely productive.

So why I am I, an unbeliever, re-blogging Geochristian’s material at all? Because as I see it, the crucial gulf is not between religious believers and unbelievers, but between those who are willing to accept reality in all its complexity, and those who prefer to impose their own dogma. And this does not affect only such matters as evolution and the age of the Earth, but such intensely practical matters as conservation, global warming, the regulation of market-based economies, and, right now, our reaction to one particular virus that happens to have mutated and evolved.
h/t Michael Roberts https://michaelroberts4004.wordpress.com/2020/05/19/what-does-mt-st-helens-teach-us-about-noahs-flood-almost-nothing/

 

 

 

GeoChristian

All I got from Mt St Helens (MSH) in the days following its May 18, 1980 eruption was a few pretty sunsets. I was an undergraduate student in my first year at the University of Utah, and most of the ash cloud passed far north of Salt Lake City. MSH became more significant for me a few years later as a geology graduate student at Washington State University, where my research project involved analysis and correlation of Cascade Range tephra (volcanic ash) layers buried at various levels in the Quaternary Palouse Loess of eastern Washington. Some of these tephra layers correlated to ancient eruptions of MSH, dated around 13,000 and 36,000 years ago.

Fortieth Anniversary

img571_900w_889h Credit: USGS, Robert Krimmel, public domain

Due in part to easy accessibility, the 1980 eruptions of MSH have been studied more closely than just about any other explosive volcanic eruption in history. Geologists have learned…

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Where rocks touch: geologic contacts

Another delightful posting from my friend Marli Miller.Thanks, Marli. I’ve blogged here earlier myself about the famous unconformity at Siccar Point, and the depositional contact at the Giants Causeway between a later lava flow, and the paleosol formed by weathering of the one before it.

geologictimepics

Geologic contacts are the surfaces where two different rocks touch each other –where they make contact. And there are only three types: depositional, intrusive, or fault. Contacts are one of the basic concerns in field geology and in creating geologic maps –and geologic maps are critical to comprehending the geology of a given area. For those of you out there who already know this stuff, I’ll do my best to spice it up with some nice photos. For those of you who don’t? This post is for you!

Depositional contacts are those where a sedimentary or volcanic rock was deposited on an older rock (of any type). Intrusive contacts are those where igneous rocks intrude older rock (of any type). Fault contacts are… faults! –surfaces where two rocks of any type have moved into their current positions next to each other along a fault.

In a cross-sectional sketch they may…

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Some Assembly Required, Neil Shubin (review) [Long]

Some Assembly Required, Neil Shubin, Pantheon/Penguin Random House, March 2020, ISBN 978-1101871331, publisher’s price HB $26.95, £20.72. Publication date March 17

A shorter version of this review has appeared on 3 Quarks Daily.

This book will be of interest to anyone who is interested in the way in which evolution actually proceeds, and the insights that we are now gaining into the genome, which controls the process. The author, Neil Shubin, has made major contributions to our understanding, using in turn the traditional methods of palaeontology and  comparative anatomy, and the newer methods of molecular biology that have emerged in the last few decades. He is writing about subject matter that he knows intimately, often describing the contributions of scientists that he knows personally. Like Shubin’s earlier writings, the book is a pleasure to read, and I was not surprised to learn here that Shubin was a teaching assistant in Stephen Jay Gould’s lectures on the history of life.

Shubin is among other things Professor of Organismal Biology and Anatomy at the University of Chicago. He first came to the attention of a wider public for the discovery of Tiktaalik, completing the bridge between lungfish and terrestrial tetrapods, and that work is described and placed in context in his earlier book, Your Inner Fish. The present volume is an overview, from his unique perspective, of our understanding of evolutionary change, from Darwin, through detailed palaeontological studies, and into the current era of molecular biology, a transition that, as he reminds us, parallels his own intellectual evolution.

18 March 2020, this just in:  https://edition.cnn.com/2020/03/18/world/fish-finger-fossil-scn/index.html Fish finger fossils show the beginnings of hands; The researchers analyzed the fin to determine its skeletal structure.

Read the rest of this entry

Evolution goes viral! (And how real science works)

I have just one good thing to say about Behe’s book: the rebuttals have introduced me to some splendid science, such as this: a four-mutation sequence with enhanced function at each step, refuting all three of Behe’s arguments; and reproducible!

Telliamed Revisited

This is the fourth in a series of posts about a new book by Michael Behe, Darwin Devolves. Behe is a leading proponent of intelligent-design creationism (IDC), which asserts that known processes cannot adequately account for evolution and, therefore, some intelligent agent must be involved in the process. Behe is a professor of biochemistry, which gives him knowledge and credentials that most IDC advocates do not have. However, my posts explain why I think his logic is unsound and his evidence weak and biased.

In brief, Behe argues that random mutation and natural selection are almost entirely degradative forces that break or blunt the various functions encoded by genes, producing short-term advantages that are so pervasive that they prevent constructive adaptations, which he claims are very unlikely to emerge in the way that evolutionary biologists have proposed. Unlike young-Earth creationists, Behe accepts the descent of living species from common…

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Darwin does devolve. Sometimes. So what?

“[T]here is in fact nothing that can alleviate that fatal flaw in Darwinism” says Professor Behe, stating the book’s central claim in the mendaciously mislabelled creationist web journal Evolution News.

The claim is clickbait, the book title misleading, and the argument long since rebutted. The historical roots of the argument show the close links between what now calls itself Intelligent Design, and biblically inspired “creation science”. The issues are important because the Intelligent Design movement gives a veneer of intellectual respectability to the denial of scientific reality. Read the rest of this entry

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