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To: ml/nj
As for post #327, I do not understand how it addresses either of the questions I raised with the professor. Perhaps you could explain.

You started the discussion of chromosome count inpost #161 with this:

Then I asked whether he believes in chromosomes, which of course he did. So I asked him how we evolved from 22 chromosome pairs to 23 chromosome pairs gradually. He didn't even try to answer.

I assume you were challenging the assumption that a species could have members with differing chromosome counts and still interbreed with viable offspring. Lots of species do, as indicated in post #327.

Humans do not show the same degree of variability in chromosome count, but it does exist and does not always result in retardation or sterility.

Particularly interesting is the mosaic count, since it directly applies to your question about evolution.

483 posted on 03/13/2003 1:19:00 PM PST by js1138
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To: js1138
Lots of species do, as indicated in post #327.

Really. I do not understand where #327 indicates that lots of species have breeding members with differing chromosome counts. I'm not even sure what polyploid means. The first definition I saw said: "Having three or more (Gk. polys, many) sets of homologous chromosomes," and for homologous chromosomes it said: "A pair of chromosomes containing the same linear gene sequences, each derived from one parent. Humans normally have 22 pairs of homologous chromosomes [plus the XX or XY]." So what is this supposed to mean?

And doesn't this relate to plants? If there are "lots of species" with mixed-chromosome-count populations as you suggest, maybe you could identify two such animal species so I could go read about them.

ML/NJ

487 posted on 03/13/2003 2:06:51 PM PST by ml/nj
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