Wednesday, March 10, 2010

Embryology

On page 80, Jerry Coyne describes one case of embryological evidence supporting evolution. As embryos, human fetuses have a fine, downy coat of hair called "lanugo," which is usually shed about a month before birth when it's replaced by the more sparsely distributed hair with which we're born. There is no need for humans to have a coat of hair in the womb because the temperature inside the womb is warm enough, and thus, it's explained as a remnant of our primate ancestry, given that fetal monkeys also develop a coat of hair at about the same stage of development which they actually keep. Coyne goes on to say that "while embryology provides such a gold mine of evidence for evolution, textbooks often fail to point this out." Why do you suppose this is? Are there certain flaws in the reasoning that embryology supports the theory of evolution? Provide other examples of how embryology supports evolution, and try to identify any flaws in those examples.

2 comments:

  1. Embryology is used in the book as a large supporter of the theory of Evolution. I think that this theory is not widely used to support the theory of Evolution because it is easily refuted by its critics, and because it is not a theory that is widely taught/ widely known. Also, Ernst Haeckel had a large part in embryology and its support of evolution. The problem is that later on his research was exposed to be not completely what he had presented it as. This made people doubt the entire concept of embryology in support of evolution. An example of embryology is that during development the human embryo forms three kinds of kidneys and two are disposed of and those two are similar to the ones of species such as jawless fish and reptiles that evolved before us. A flaw in this is that the theory of evolution in itself is about organisms adapting in order to survive and reproduce in the most efficient way. Why would an organism waste the energy of making three kidneys when it only needs one of them? It does not support the theory of evolution in the way that it does not make development more efficient or help an organism survive and reproduce. The lack of strong links supported by research between embryology and evolution provides many cracks for critics to tear apart the connection. Lastly, as Coyne mentions in the book on page 80 "I have met obstetricians, for instance, who know everything about the lanugo except why it appears in the first place," (80). This is emphasizing the fact that embryology is not widely known or taught enough for it to be used effectively as a support for the theory of evolution for a wide variety of people.

    ReplyDelete
  2. Sorry forgot to post my sources:
    www.pbs.org/wgbh/evolution/library
    www.creationresearch.org/crsq/articles (in order to find what the opposition used as their arguments)

    ReplyDelete