Re: How Can Evolution Change the Number of Chromosomes?

Robert Carnegie wrote:
John Wilkins wrote:
J. J. Lodder wrote:
<kruskal@xxxxxxxxx> wrote:

hersheyhv wrote:
My understanding is that both types of hybrids have *reduced* fertility
related to the number of chromosomal rearrangements, with mules being
so reduced that the possibility of fertility is rare enough that a mule
that did so was called "Blue Moon".
I know I am changing the subject to "What is a Species":

I thought that dog/wolf and dog/coyote and any two cats had zero
reduced fertility. Since dogs actually do mate pretty frequently with
coyotes (these days, at least), doesn't that make them the same
species?

I know the answer is 'no', but I don't understand why.
Because there is nothing to understand.
What is, or isn't a species
is to some extant nothing but an arbitrary convention.

Best,

Jan

I completely disagree. The arbitrariness comes in the use of subjective
diagnostic criteria, but species are no more arbitrary than the fact that we
sometimes name streets, which are real things, with different names.

One can argue that the real things are individual organisms, and
grouping them into species is not a matter of absolute truth.

Having said that, in some cases "individual organism" is not a
straightforwardly correct term, either.

I suppose it'll all have to do...

All group objects are somposed of other objects. Organisms (of the
multicellular variety) are groups, but they are no less real for that. Species
are real things. They just aren't all the same *kind* of real things.

--
John S. Wilkins, Postdoctoral Research Fellow, Biohumanities Project
University of Queensland - Blog: evolvethought.blogspot.com
"He used... sarcasm. He knew all the tricks, dramatic irony, metaphor, bathos,
puns, parody, litotes and... satire. He was vicious."

.

Relevant Pages

  • Re: How Can Evolution Change the Number of Chromosomes?
    ... related to the number of chromosomal rearrangements, with mules being ... so reduced that the possibility of fertility is rare enough that a mule ... I know I am changing the subject to "What is a Species": ...
    (talk.origins)
  • Re: How Can Evolution Change the Number of Chromosomes?
    ... related to the number of chromosomal rearrangements, with mules being ... so reduced that the possibility of fertility is rare enough that a mule ... What is, or isn't a species ... The arbitrariness comes in the use of subjective ...
    (talk.origins)
  • Re: How Can Evolution Change the Number of Chromosomes?
    ... related to the number of chromosomal rearrangements, with mules being ... so reduced that the possibility of fertility is rare enough that a mule ... What is, or isn't a species ... The arbitrariness comes in the use of subjective ...
    (talk.origins)
  • Re: How Can Evolution Change the Number of Chromosomes?
    ... related to the number of chromosomal rearrangements, with mules being ... so reduced that the possibility of fertility is rare enough that a mule ... What is, or isn't a species ... The arbitrariness comes in the use of subjective ...
    (talk.origins)
  • Re: Fundamental theorems, dilemmas, fitness, and information.
    ... >>> colder even if the individual ORGANISMS that constitute the species ... > and react to that perception becomes captured in the genome. ... evidence that has been reconstructed from the past. ... > my point about the species being able to learn, ...
    (sci.bio.evolution)