• Darwin’s Doubt – Chapter 1 – Part 3

    I’ve discovered that Meyer has conveniently divided his chapters into sub-headings, so I’ll be tackling one sub-heading per post.

    This sub-heading is called The Cambrian Explosion and the Action of Natural Selection.  Once again, I hope this is a historical discussion, though there is evidence that it is not.  I am constantly amazed by creationists’ conflating Darwin with modern evolutionary theory.  Darwin was a smart guy, but Wallace was well on his way to figuring out the same principles.  Darwin didn’t know anything about DNA, molecular biology, activator genes, etc. etc. etc.

    Meyer briefly mentions three of the major tenets of Darwinian evolution (and I”m using the term correctly): variations, heritability, and the struggle for survival.  Again though, this is Darwin’s ideas, not modern evolution, so any arguments made to disprove this are strawmen.  Only attacking modern evolutionary theory will work here… and no matter how much one says “Evolution is wrong”, it still doesn’t mean that creationism is right.  Only positive supporting evidence will do and there isn’t any.

    Meyer again talks about macromutations and complains that only variations are within species.  He says,

    Only minor variations meet the test of viability and heritability.

    That’s a big claim.  And, Meyer refuses to support it.  But let’s talk about this a second.  What does this even mean?

    What Meyer is saying, in a complex way, is really that in spite of the thousands of years of variation, dogs are still dogs, wheat is still wheat, and mosquitoes are still mosquitoes.  This is a classic creationist trope.  It was originally used to discredit evolution in support of Young Earth Creationism.

    By saying that even over recorded history things couldn’t change, even when we tried, then there’s no way for organisms to change into new species, therefore, a young Earth is supported.

    Yeah, it’s crummy logic, but at least it doesn’t have evidence either.

    I want to show you something.  This is a visual clue of something that Dawkins has said.  Dawkins says (Greatest Show on Earth, 393 of 8279 on Kindle Edition)

    Every individual along the chain [of ancestry] is as similar to its neighbors in the chain as mothers and daughters are expected to be.  And more similar to its neighbors in the chain, as I have also mentioned, than to typical members of the surrounding population.  [emphasis in original]

    What Dawkins is saying is that evolution is about populations, not individuals.  Within a population, you can have much greater variation than would be expected between parent and child.  This is trivially easy to show.

    Members of the Cell Biology and Metabolism Program: National Institutes of Health http://cbmp.nichd.nih.gov/
    Members of the Cell Biology and Metabolism Program: National Institutes of Health

    Just comparing some basic physical characters, within this small group of people is a huge variation in morphology.  Of course, they are still humans.  That’s not the point of the picture.

    The point is that within a population, there is much more variation between groups of individuals than between parent and offspring.  Here’s a discussion on the types of speciation and how this massive variation in population can easily result in a new species (or two or three).

    Humans are a poor example to use for this.  Because of our technology, we can overcome physical and biological barriers to interbreeding.  In a way, we’ve supplanted evolution with technology, but that’s a whole ‘nother can of worms.

    Both Dawkins and Meyer agree that evolution is slow and that we wouldn’t expect to see new species (by this, I think that they both mean obviously new species with huge morphological differences) in a person’s lifetime or even in all of recorded history.

    Meyer closes this section with a curious statement.

    More significant changes to the form and anatomical structure of organisms would, by the logic of Darwin’s Mechanism, require untold millions of years, precisely what seemed unavailable in the case of the Cambrian explosion.

    WTF?  Seriously?

    The Cambrian time period lasted for well over 60 million years.  Before 580 million years ago, single-celled organism were almost all that existed.  Over the following 70-80 million years, the rate of evolution increased by an order of magnitude (note that this is in dispute and some sources say that the evolution rate was comparable to most of the rest of the rest of the time periods of the Earth).

    All present phyla seemed to have appeared within the first 20 million years.  Although, this again is an active area of research and many papers suggest that the modern phyla were present well before this time frame.

    Regardless of all the caveats and current research and all that stuff, Meyer is saying that “millions of years” are “unavailable in the case of the Cambrian explosion”.

    So, 20-70 million years isn’t the “millions of years” that Meyer thinks are needed here.  What does ‘millions of years’ mean in this case?

    I’d like to add at this paper (2006) suggests that the last common ancestor of humans and chimpanzees was between 4 and 6.3 million years ago.  There are a variety of ranges, but these seem to be the most current and used the largest amount of molecular data to generate the date range.

    So, the diversification of humans and chimpanzees happened in (perhaps) 1/10th the length of the Cambrian explosion.  I would submit that the evolution of intelligence (something the dinosaurs didn’t do over a hundred million years) was just a great a change as the development of hard shells.

    Whales and dolphins went from purely terrestrial mammals to purely ocean dwelling in less than 50 million years.

    So, I’m honestly not sure what Meyer’s complaint is here.  Peer-reviewed research shows that massive variation in species (and larger groups) can happen in way less than 50 million years.  Meyer seems to agree, but then says that 50 million years isn’t enough time.

    Finally, I’d like to point out the purely arbitrary nature of taxonomy.  I’ve talked about this before, but the whole Linnean system is purely made up.  What is a phylum?  A phylum is a group of organisms that all share a particular character.  That’s all that it is.  Would anyone say that the first organism with that new character should be a new phylum?  No, that’s silly.

    But, over time, because that character was so successful (for example, existence of a notocord), it came to have well over 100,000 species within it.  In other words, saying that new phylum appeared in the past is useless without knowing how those various phyla appear now.  And no one can predict what phyla have appeared in the last few years… we won’t know until millions of years down the line when that character is in thousands of species.

    Meyer continues to make claims without evidence and without understanding what evolution really is and how it really works.

    UPDATE: corrected for plural issues with my Latin and for a slightly better flow.

    Category: Book ReviewEvolutionScience


    Article by: Smilodon's Retreat