Re: Ricland, Robinsons and Racism


"Don Aitken" <don-aitken@xxxxxxxxxx> wrote in message
news:bdumk398b07o10vd88m4ueo0vbo1mmqqmn@xxxxxxxxxx

Biologists will know that the above is a little too simple in several
ways - the classic case, of which there are several examples, is a
species which has a series of varieties, each of which can interbreed
with its immediate neighbours, but the varieties at the ends of the
range cannot interbreed with each other. Even the concept of "species"
is slippery in these cases, and the concept of a race or variety is
inherently a vague one. That doesn't make it entirely meaningless,
though.

Of course, "race" isn't normally used in taxonomy - "variety" and
"sub-species" are more common. One definition of a species, used normally
for vertebrates, is the ability to breed and produce fertile young. I once
had a major disagreement with a botanist who was claiming that geographical
distribution should be included in that definition so that if 2 types of
plant which could easily combine to give a fertile variant were
geographically separated, they should be seen as distinct species! That view
is not as prevalent as it was. Variation in humans is fairly superficial,
and mostly due to environmental selection (eg in the days before vitamin
supplements, paler people tended to do better in the far north because their
skin synthesized more vitamin D from the limited sunlight). A "sub-species"
will breed true in crosses with another member of the same sub-species, but
is able to cross with others within the overall species, to produce
something new.
There's a lot of reorganisation going on now as people get around to
checking DNA.
EOL
Lesley Robertson


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