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Science Forum

Science Forum

  1. Subscriber moonbus
    Uber-Nerd
    24 Nov '17 15:10
    http://www.bbc.com/news/science-environment-42103058

    A new species has emerged and we saw it happen.
  2. 24 Nov '17 21:04 / 2 edits
    Originally posted by @moonbus
    http://www.bbc.com/news/science-environment-42103058

    A new species has emerged and we saw it happen.
    yes, indeed.
    It says "...This new finch population is sufficiently different in form and habits to the native birds, as to be marked out as a new species, and individuals from the different populations don't interbreed... "

    So this new species is at a result of hybridization between two related species but then followed by rapid further changes via evolution so that they are now rapidly become so different in characteristics from either of their two parent species that they no longer interbred with either of their two parent species thus, by any reasonable definition of species, they are now a new species.

    This observation of such a rapid species change is yet further evidence in support of punctuated equilibrium (see https://en.wikipedia.org/wiki/Punctuated_equilibrium) although the evidence for punctuated equilibrium was already so strong that it really was already scientific fact.
  3. Subscriber moonbus
    Uber-Nerd
    24 Nov '17 23:08
    It certainly indicates that evolution proceeds by multiple mechanisms, not only natural selection and genetic mutation.
  4. Subscriber ogb
    25 Nov '17 03:12
    Originally posted by @moonbus
    It certainly indicates that evolution proceeds by multiple mechanisms, not only natural selection and genetic mutation.
    yes and don't forget TRANSPERMIA !!
  5. 25 Nov '17 08:36
    Originally posted by @moonbus
    It certainly indicates that evolution proceeds by multiple mechanisms, not only natural selection and genetic mutation.
    well, just the combination of these mechanisms;
    1, natural selection
    2, random genetic mutation and/or the occasional hybridization
  6. Subscriber moonbus
    Uber-Nerd
    25 Nov '17 16:53
    Three separate mechanisms gives a total of seven possible combinations.
  7. 25 Nov '17 18:27 / 1 edit
    Originally posted by @moonbus
    Three separate mechanisms gives a total of seven possible combinations.
    natural selection cannot work without genetic variation but natural selection by itself cannot produce genetic variation. So there must be at least one more mechanism to produce that genetic variation first so that natural selection can then act on it else no evolution. That gives just three possible combinations.

    Possibly one more mechanism to add to those three depending on how you define things; gene recombination via sexual reproduction. But not sure if one can validly squeeze that into the same category as "random mutation" because that is stretching its meaning a bit.