From: "Dan Meliza"
Subject: RE: (urth) Marble's prophecy Date: Thu, 21 Mar 2002 09:40:52 -0800 Hi Marc, I haven't had a chance to look at the pics (qualifying exams, alas), but Xenopus laevis is naturally polyploid (making it difficult to make transgenic animals, for anyone who cares), and N varies greatly between species in the genus (something like 12N for one of those buggers). I think it might be a little spurious to claim that simply doubling the number of chromosomes would double limb count. Development is a lot more complex than that. best, dan -----Original Message----- From: maa32 [mailto:firstname.lastname@example.org] Sent: Monday, March 18, 2002 9:19 PM To: email@example.com Subject: (urth) Marble's prophecy [snip] Now that I look at it again, I see the one one the left is 2N, the one on the right is 4N. Note that the front limbs of the frog also have three little digits that should be one (like three psuedo-hands or something) If you click on the arrows at the bottom of that page of the presentation, you can see the whole 31 slides. There are other hybrid species produced through polyploidy, including lizards and flies. The flies also have a doubling of the hind legs that is pretty interesting if you advance a few slides. Marc Aramini -- --