wells is peeved with haeckel’s embryos

Another misleading offering from Icons of Evolution:

VERTEBRATE EMBRYOS. Why do textbooks use drawings of similarities in vertebrate embryos as evidence for their common ancestry — even though biologists have known for over a century that vertebrate embryos are not most similar in their early stages, and the drawings are faked?

The short answer: most texts no longer do this; editors & publishers have corrected their error as they’ve become aware of it.

The long answer:  in this claim Wells is referring to a series of drawings by the German embryologist Ernst Haeckel, which seemed to show very strong similarities in form between the embryos of a number of different vertebrate groups. Haeckel may well have fudged these drawings to exaggerate the embryos’ similarities – but nonetheless, current research does show that early vertebrate embryos do in fact have a number of similarities. And embryos of species that recently shared a common ancestor have more features in common than more distantly-related groups. For example, at some stage in their development all chordate embryos have a notochord, a dorsal nerve cord, a tail that extends beyond the anus, and pharyngeal pouches – features which are missing from all other animal taxa. (These four features are examples of homologous structures.) And within the chordates, mammal embryos are more similar to each other than they are to reptile embryos.

Wells also tries to make out that Haeckel’s flawed drawings formed the basis of Darwin’s understanding of embryology, which was one line of evidence in The origin of species. In fact, Haeckel’s work was published well after Darwin completed The origin, so could hardly have had an impact. What did impress Darwin was Haeckel’s work on phylogenetic trees, which supported and illustrated his own key concept of descent with modification. In other words, he was delighted with Haeckel’s application of the theory of evolution via natural selection, rather than using Haeckel’s work to support his own.

What’s more, Wells berates Haeckel, not only for fudging his drawings, but also for not including information on monotremes [echidnas & platypus] in his figures. Now this really is silly. As Alan Gishlick points out, monotremes hadn’t even been discovered in 1866, when Haeckel published his famous embryology work! What’s more, when the scientific world did get its collective hands on monotreme specimens, monotremes were recognised as mammals because they had common features of embryonic development. This is an excellent example of how important studies of comparative embryology are to our understanding of evolution – and ‘evo-devo’ (or evolution & developmental biology) is one of the fastest-growing fields in biology today.

5 thoughts on “wells is peeved with haeckel’s embryos”

  • Alison Campbell says:

    You mean Graeme Finlay’s course (http://www.cce.auckland.ac.nz/cce/continuing/index.cfm?P=8548&ClassNumber=77959) on ‘resolving the controversy between evolution & creationism’? (typing from memory here – should have opened it in another window!) We’ve corresponded in the past, & good on him for sticking his neck out & running it. But I wish, oh how I wish, that he hadn’t cast it as a controversy. That to me gives cdesign-adherents(& others) the idea that their framing of the whole thing as ‘controversy’ has some legitimacy…

  • Its a good point! Maybe he could have called it “Evolution: the unnecessary fuss” !!
    I’m not sure I’d want to run it, either. Does he teach something similar in university classes?
    I once assisted at a GE/GMO education “mixer”: we were to just turn up, no prepping, and were let loose in a room with people who wanted to ask us questions. An interesting sort of an exercise, although a bit nerve-wracking at first. Most people were pretty reasonable, thankfully, although you suspected one or two of the Rastafarian hair-style types weren’t actually taking in what you were saying all that much! (Either from prepping themselves with a little of their favourite weed, or just lack of interest in other views.) Funnily, my memory is that a good number of the people that turned up to assist weren’t geneticists, but actually “protein” people. Not sure what to make of that!

  • Alison Campbell says:

    I don’t know if he does any ‘formal’ teaching on the subject but it would certainly be infused in some of his work, I think.
    I had a student come to see me recently who asked about the possibility of setting up a ‘club’ (for want of a better word) for the undergrad students to come & discuss big science issues. Including evolution (& most definitely not from a creationist perspective!). He’s certainly identifed a need; the difficulty for me would not be so much in setting something like that up but in getting a reliable source of ‘knowledgeable others’ to come along & talk – I can’t do things like the big bang, for example!

  • Protip for religious people out to prove science wrong;
    If the information you have aquired is false in any way, simply look else where.
    Science is full-proof. You wouldn’t attack mathematical fact with questions (that apparently make it incorrect) if you saw ‘2 + 2 = 4’ and you equally shouldn’t if there’s something else written on science that has been through peer review and has been tested.
    . 2 + 2 = 4
    . Fish have gills
    . Oxygen is essential to human life
    . Evolution has an explanation to life
    . Evolutionary biology is now considered essential to all biological studies and work
    . Roughly 30% of men in America suffer from pre-mature ejaculation
    . A majority of Creationists attempt to disprove fact because the fact gives an alternative to a loving sky daddy who promises them the idea of the best mortal greed (eternal life)in exchange for worship ceremony and the attack, verbally and physically (stated in the bible for example) to people who think twice about the bible.
    All these dot points are currently FACT. When Creationists can prove that there’s an alternative answer to; ‘2 + 2 = 4’ then I’ll consider that maybe Scientific Fact (which has been tested several times and been through peer review) isn’t fact because of that persons applicable religion.
    I am open to opinion and anything anyone has to say, if they can show reasonable evidence for their claims.
    Also my disrespects go out to the pathetic individual who stated; “Another misleading offering from Icons of Evolution”. Slandering Science with motive derived from Religious beliefs is unfair to those who want only to learn and choose not to live a life of ignorance.
    If you read this and felt insulted, all I feel is pitty for your attitude and I insist on getting a psycological check-up in case you suffer from a lack of ability to open yourself to reason.
    Have a nice day.

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