Thursday, 30 July 2015

A criticism of Stephen Palmer's talks at the Coventry Creation Day - 6

Given both the long-standing, overwhelming scientific consensus on the reality of evolution, and the fact that there are many prominent life and earth scientists who are committed Christians and obviously do not regard evolution as intrinsically anti-theistic, the burden of proof clearly lies solely on the evolution denialists in our community to show why such a robust consensus that unifies both believers and non-believers is wrong. Unfortunately, evading the burden of proof is a common tactic among evolution denialists. One attempt to shift that burden of proof is to assert that scientists are the least qualified to speak authoritatively on evolution. The justification for this bizarre claim is that scientific specialisation means that each individual scientist can only speak authoritatively on a narrow subject, and therefore not offer an opinion on the remainder of the field. The argument therefore is that each scientist is accepting on trust what others outside their area of competence says, and therefore accepts evolution on faith.

This poor logic can readily be demonstrated by the always-useful tactic of replacing evolution with any other well-accepted scientific fact and seeing how unconvincing the logic is:
"As research scientists are hyper-specialised, they are therefore manifestly unqualified to speak authoritatively on continental drift. Individual geologists may be experts in geophysics, stratigraphy, radiometric dating, biogeography, or vulcanology, but given that - say - the geophysicist has probably never seen a fossil or the biogeographer never dated a fossil, they are simply looking at a tiny part of the whole, and merely taking the word of the other scientists."
Similar points could be made about the germ theory of disease, the atomic theory of matter, or any other well-attested fact for which a robust scientific theory exists, with the fundamental principle being the difference between the scientific theory that seeks to to explain the scientific facts (common descent in this case) and the theoretical mechanism that seeks to explain these facts (the modern synthetic theory of evolution). When framed this way, the patently unconvincing nature of this attempt by evolution denialists to evade the burden of proof is obvious.

Prior to undertaking graduate studies and beginning their hyper-specialisation, evolutionary biologists in their undergraduate studies learn about the facts of common descent and large-scale evolutionary change such as:

  • The biogeographic distribution of species
  • Atavisms
  • Comparative anatomy
  • Comparative genomics
  • The fossil record
  • Developmental biology
Certainly, once they complete their PhD and embark on a research career, the life scientist will have begun the process of hyper-specialisation, but having studied the evidence for common descent and large-scale evolutionary change at the start of their career, they will see why, to quote the legendary geneticist Theodosius Dobzhansky, nothing in biology makes sense except in the light of evolution.

Furthermore, given that the hallmark of a good theory is its explanatory and predictive power, even in their areas of specialisation, biologists will be able to see how well evolution explains and integrates what they see, as well as allows them to make useful predictions that can be tested. For example in a 2009 paper on tooth enamel genes in placental mammals, the authors predicted that in animals that do not have teeth or have teeth without enamel, the genes coding for these tooth enamel proteins would be corrupted:
Enamel is the hardest substance in the vertebrate body. One of the key proteins involved in enamel formation is enamelin. Most placental mammals have teeth that are capped with enamel, but there are also lineages without teeth (anteaters, pangolins, baleen whales) or with enamelless teeth (armadillos, sloths, aardvarks, pygmy and dwarf sperm whales). All toothless and enamelless mammals are descended from ancestral forms that possessed teeth with enamel. Given this ancestry, we predicted that mammalian species without teeth or with teeth that lack enamel would have copies of the gene that codes for the enamelin protein, but that the enamelin gene in these species would contain mutations that render it a nonfunctional pseudogene. To test this hypothesis, we sequenced most of the protein-coding region of the enamelin gene in all groups of placental mammals that lack teeth or have enamelless teeth. In every case, we discovered mutations in the enamelin gene that disrupt the proper reading frame that codes for the enamelin protein. Our results link evolutionary change at the molecular level to morphological change in the fossil record and also provide evidence for the enormous predictive power of Charles Darwin's theory of descent with modification.[1] (Emphasis mine)
Far from being a liability, the specialisation of these scientists means that they are uniquely placed to speak with authority about why this evidence provided powerful evidence for common descent and large-scale evolutionary change. Furthermore, when other scientists in other specialties (biogeography, ecology, developmental biology) also state that the evidence in their sub-specialty provides powerful evidence for common descent, and that this evidence confirms the predictive power of descent with modification, far from being a liability, this hyper-specialisation means that irrespective of their specialty, mainstream scientists agree that the evidence in their separate specialties confirms the reality of common descent. This is why the fact that > 99% of professional biologists accept evolution is so powerful. It's not an appeal to popularity, but rather the recognition that the vast overwhelming majority of professional scientists who examine the evidence agree that it "provides evidence for the enormous predictive power of Charles Darwin's theory of descent with modification."

Finally, this special creationist argument ignores the fact that science at heart is organised scepticism, with everything held provisionally, pending further evidence. Furthermore, given the highly competitive nature of science, claims that don't add up, such as the recent claim that under certain conditions bacteria could utilise arsenic instead of phosphorus, are rapidly exposed. As the author of the website Skeptical Raptor, who has worked in the pharmaceutical industry notes:
[s]cience has always been open to criticism and analysis, in fact, part of developing those theories and principles is provide evidence in the most transparent manner possible, and then stand in front of your peers for hostile and critical questions. No real scientist could get away with a claim that “smoking is healthy” today, because there would be a hundred scientists jumping on it, and showing the contrary evidence.  
We have high quality open source journals that publish information quickly (still heavily peer-reviewed), so that claims that don’t make scientific sense get smashed out of existence quickly. As opposed the misinformation pushed by pseudoscientists, scientific evidence is based on the quality and quantity of evidence. That’s why we know that evolution is a fact, anthropogenic global warming is a fact, HIV causes AIDS is a fact, and vaccines being safe and effect are a fact.[2]
Put another way, bro. Palmer is obliged to explain why tens of thousands of highly skilled scientists are mistaken in their claims that their area of expertise provides evidence for the predictive and explanatory power of evolutionary biology" particularly when his area of expertise lies well outside these areas. It is difficult at best to accept that his opinion on those matters is more authoritative than those who actually specialise in these areas. 

Do scientists trust other scientists outside their sphere of expertise? Of course they do. Is that a problem? Not at all. As a medical doctor, my area of expertise lies in one area, which means that if I want an opinion on areas such as infectious diseases, orthopaedic surgery, endocrinology, or cardiology, I will seek the opinion of a specialist in those areas, simply because it is impossible for me to maintain expertise in every area of medicine which has a bewildering variety of subspecialties. In other words, I trust that the other experts know their specialty, and are competent. My lack of understanding of those areas outside my small area of expertise however does not mean that I am not able to defend modern medicine against the pseudoscience of alternative medicine. The point is clear and  hardly needs further elaboration.

Fact and Theory - Clarifying Misconceptions

I cannot stress often enough that unless you properly define something, any criticism you make of it will be irrelevant as you will be attacking a straw man. Opponents of evolution are notorious for failing to define evolution, as can be seen by special creationists who attack evolution because it does not provide an explanation for the origin of life, or claim that 'microevolution has been observed, but macroevolution is a baseless hypothesis." Both those claims betray a profound ignorance of evolutionary biology, and make it impossible to take seriously the claims made by anyone advancing such a straw man version of evolution.

Once again, evolution refers to fact (common descent) and theory (the modern evolutionary synthesis). Abiogenesis is a related, but separate discipline which seeks to explain the emergence of life from non-life. At present, it is fair to say that at the moment, no one knows exactly how life emerged from prebiotic precursors, though there are a number of compelling hypotheses. However, the fact that we do not have a robust theory of abiogenesis does not mean the fact of common descent is in doubt. Likewise, problems real or imagined with the modern synthetic theory of evolution do not mean that the fact of common descent it seeks to explain is in doubt.

The example of gravity provides an excellent analogy. Gravity refers both to fact (gravitational attraction, gravitational lensing, planetary motion) and theory (Newton's theory of gravity, general relativity). Newton's theory of gravity held for centuries until it could no longer explain certain phenomena which genera relativity was able to explain. 

As successful a theory as general relativity is, we know that it is incomplete, because it cannot explain gravity at the quantum level, and this is a fairly major problem. However, any physicist who claimed that gravity did not exist because GR could not explain gravity at the quantum level, or that GR was worthless as a theory because it is not a quantum theory of gravity would not be taken seriously. Likewise, anyone who claimed that common descent does not exist because modern evolutionary theory does not provide a robust explanation of abiogenesis, or asserted that the modern synthetic theory of evolution did not have any predictive or explanatory power because of unsolved problems in evolutionary biology would not be taken seriously outside of special creationist circles.

Along with a failure to properly differentiate between abiogenesis and evolutionary biology, and evolution as fact and theory comes the special creationist confusion over microevolution and macroevolution. While special creationists claim to have no problems with microevolution ("change within species") they allege that while microevolution is uncontroversial, macroevolution has never been observed. One of the problems with the micro-macro claim is that it fails to acknowledge that as I pointed out earlier, the fact of evolution (common descent and large-scale evolutionary change) is no longer in doubt, and has been accepted by the overwhelming majority of competent scientists for well over a century.

The evidence for common descent comes from disciplines as disparate as palaeontology, comparative genomics, and developmental biology, and outside a tiny minority of fundamentalists with science degrees whose rejection is based not on science, but adherence to dogma, there is no doubt among life scientists of the truth of common descent.

[1] Meredith R.W. et al “Molecular Decay of the Tooth Gene Enamelin (ENAM) Mirrors the Loss of Enamel in the Fossil Record of Placental MammalsPLoS Genetics (2009) 5(9): e1000634. doi:10.1371/journal.pgen.1000634
[2] Skeptical Raptor "Debunking the 'mistakes science made' tropes?" Skeptical Raptor's Blog 27th May 2015