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

Charles Darwin Question

  1. Apr 13, 2008 #1

    I'm having a lot of trouble with this statement and was wondering if someone could help clarify or give me a brief explanation of Darwin's conceptual gap??

    It reads "Charles Darwin presented ideas on the causes of organismic change through time.
    A primary conceptual gap existed which left his theory open to criticism."

    I have tried endless hours searching the web for more information and reading through my textbook but still had no luck...

    Thankyou I would really appreciate your help. :)
  2. jcsd
  3. Apr 13, 2008 #2
    I don't know what exactly the "conceptual gap" is that your source is referring to, but some parts of the original formation of evolution by Drawin isn't in agreement with our current knowledge of evolution (neo-Darwinism). For instance, Darwin proposed a genetic mechanism of inheritance called "Pangenesis" but it has since between replaced with "Mendelian inheritance" as part of the modern sysnthesis. Note that although there was disagreement about the mechanism, the existance of the process known as evolution isn't in any scientific debate.
  4. Apr 13, 2008 #3


    User Avatar

    Staff: Mentor

    It would help a lot if you provided your source and the context of the quote.
  5. Apr 13, 2008 #4
    Ah yes! I didn't think of that approach!! Thankyou so much! :)
  6. Apr 13, 2008 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    If you have tried to provide a link and can't, send a Private Message to me and I can get your link to work (we recently changed some things here that will hinder you from posting a link until you have a few more posts...blame the spammers for ruining it for everyone). Context would really be helpful here.
  7. Apr 13, 2008 #6
    Oh I actually understand it now after missing a little important fact...
    But thankyou for telling me about posting links Moonbear, I'll remember it for next time :)
  8. Apr 14, 2008 #7
    What approach?
  9. Apr 30, 2008 #8
    the source is a Biology assignment, and the question is "In 1859, Charles Darwin published Thw Origin Of Species in which he presented ideas on the causes of organismic change through time.
    A primary conceptual gap existed which left his theory open to criticism. What was that conceptual gap?"

    I too have been trying to find the answer with little success.

    Any ideas peoples?
  10. Apr 30, 2008 #9
    Are these really kids asking for help with biology homework?

    Or are they creationist trolls fishing for a "conceptual gap"?

  11. Apr 30, 2008 #10
    Not cynical at all are you?!?

    wouldn't call myself a kid, (24 - I know, how ancient!!!)

    but definately asking for help with bio assignment, is very late and still no clue... have sadly run out of coffee.... woe is me :(

    personally have no time for creationists - twats don't think animals go to heaven!!! - if i were god i'd prefer the critters to the humans, but thats just me :)

    so any ideas or?!?
  12. Apr 30, 2008 #11


    User Avatar
    Science Advisor
    Homework Helper

    The conceptual gap was that genes are discrete.
    The problem at the time was that any small advantage would be diluted out if you think of inheriting traits as analogue quantities. It's only once you know that a trait/gene is fully inherited or not at all that the mechanism makes sense.
  13. Apr 30, 2008 #12
    The conceptual gap you refer to is probably the fact that Darwin didn't have a coherent notion of where his "variants" could come from in the first place. Natural selection nicely explains how evolution happens by preexisting variants becoming more prevalent due to environmental pressures. It does not say anything about where the varients came from to start with.

    Darwin may have had ideas about this, but whatever he thought it probably isn't the accepted view today. Darwin didn't know about mendelian genetics or mutations etc so he couldn't have had a modern view of where his variants came from.

    Though I haven't actually read Darwin's original writings so take this with a grain of salt...

    edit: mgb and I cross-posted. His post also makes sense, that may be the answer you are looking for.
  14. Apr 30, 2008 #13


    User Avatar
    Science Advisor
    Homework Helper

    The theory was called "Blending inheritance".

    The objections at the time were that an old trait could be breed back into a line - you could breed small dogs for size and strength back into wolves. This had practical importance to breed efficent cattle and sheep and would be impossible if the trait had been diluted to a tiny part by many generations.

    The example given by Darwin's critic Fleeming Jenkin (excuse the 19th C world view!)
    - imagine a white man shipwrecked on an island, however superior his gifts they would be diluted until many generations on there would be no trace of white skin among the islanders.
  15. May 1, 2008 #14
    *Cough* Neo-Darwinism came up around 1900 and it is NOT the current theory of evolution. The current one actually does not have a concise name and is often referred to as new modern synthesis and sometimes even postmodern synthesis (modern synthesis came up around the 1950s).

    One of the primary conceptual gaps in Darwin's original theory is the means of inheritance. Genes were unknown at that time and he could not really formulate how traits are passed on. In fact, he also accepted the possibility of Lamarckian inheritance, a notion that was refuted by the concept of neo-Darwinism.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook