> In my earlier post, I referred to the German group who put together
> the symposium "Typen des Lebens". They demonstrate that the dog
> family and the horse family do constitute "Basic Types" - linked
> genetically within the family but with no linkages outside the
> family. This volume does not claim that these "Basic Types" are to
> be equated with the Genesis kinds - for that is loading the biblical
> text with a technical meaning which (some of us think) it does not
> have. One strong inference from the scientific analysis of the data
> is that the members of the dog-family show evidences of having
> descended from a common ancestral population. Similarly for the
> horse-family. Evidence for genetic linkages from these populations
> to any other population is totally lacking. This is fully consistent
> with the scenarios developed by PCs and YECs.
Hmmm, I've got a problem with those last four sentences. Each, by itself,
is fine, but taken together they seem to sneak in a subtle but important
shift-of-definition somewhere before the last sentence.
If I correctly understand your description of the German group's work,
David, the only types of "genetic linkages" they looked for were: groups
of existing species which could form an inter-breeding set. (Species A
can breed with B, which can breed with C, which can breed with D, are all
part of one set even if A can't breed with D.) They did not, for example,
quantify genomic homologies between non-inter-breeding populations.
These sentences:
> One strong inference from the scientific analysis of the data
> is that the members of the dog-family show evidences of having
> descended from a common ancestral population. Similarly for the
> horse-family.
imply that present-day "genetic linking" should be taken as evidence of
common ancestry. That's fine with me.
This sentence:
> Evidence for genetic linkages from these populations
> to any other population is totally lacking.
is also fine, provided we remember what "genetic linkages" means to this
research group, i.e. existing species which can form an inter-breeding
set.
The final sentence:
> This is fully consistent
> with the scenarios developed by PCs and YECs.
is also true, but unhelpful, because their results are also fully
consistent with EC (or even naturalistic evolution). In other words, the
existence of reproductively isolated groups of present-day species is no
big surprise to anyone.
The "subtle shift-of-definition" I complained about is the implicit
equating of "present-day genetic linkages" (as defined by that research
group) with common ancestry --- implying that "genetic linkages" are the
ONLY valid type of evidence for common ancestry --- in which case EC would
be in trouble
I know that you weren't deliberately trying to "pull a fast one," David.
I just thought you'd like to know that your word choice was implying
things that you didn't intend.
--------------------------------------------------------------------------------
"I made no attempt to be innacurate, |
but I want to make it clear that I | Loren Haarsma
was not attempting to be precise." | lhaarsma@opal.tufts.edu
--Josh Steiner, Treasure Dept. Chief of Staff |