Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Then and now

  1. Sep 21, 2005 #1
    Billions of years ago, what if a species had been born without a particular part of its body for i.e reproduction ?

    In developmental biology, why can an egg and a sperm gives birth to an embryo, which was termed I think only after we had already known more about this kind of phenomenon ? Why does the cell does divide and shape into a different kind of animal but human shape with nose, long legs (:smile: I know some have very short legs, very long back but always love to wear shorts :biggrin:), etc.

    Another question is why couples (interacial) give birth to children whose skin is the same as their father not ther mother, mostly like that ?

    Thank you
  2. jcsd
  3. Sep 21, 2005 #2


    User Avatar
    Science Advisor
    Homework Helper

    I quote the words of Rene' Thom:

    "all creation or destruction of form or morphogenesis can be described by the disappearance of the attractor representing the initial form and their replacement by capture by the attractors representing the final form".

    I know, it's cryptic. Know about the Mandelbrot Set? Take a simple-looking difference equation and iterate it and a marvelous pattern develops. Right? Doesn't DNA iterate? That is, replication is of a previous strand which was replicated previously and so on. Now some would argue that DNA does not change after replication so it's not the same as that Mandelbrot stuf. Are we sure about that? When DNA replicates, are the product strands identical in every way to the strands that bore it or is there some change we're not aware of? I don't know but I suspect it's not. Perhaps the Biology gurus in hear can answer that for me.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook