That doesn't make evolutionary sense.

Post #216,389 by Andrew Grygus 7/25/05 8:47:39 PM Reply	That doesn't make evolutionary sense. If cats ate sweet things at one time, failure of the sweet detectors would be a survival negative and selected out. If sweets were already irrelevant, degradation of the sensors would not matter. In any case, the researchers specifically state it was the totally carnivorous lifestyle of cats that allowed the sweet sensors to go haywire, as quoted in today's Los Angeles Times. But that's what you get for listening to NPR when you're supposed to be watching Fox News. [link\|http://www.aaxnet.com\|AAx]
Post #216,392 by broomberg 7/25/05 9:12:59 PM Reply	Not according to this guy It is an unknown. [link\|http://news.com.com/Why+cats+will+never+live+the+sweet+life/2100-1008_3-5803492.html\|http://news.com.com/...08_3-5803492.html] "What we still don't know is--which came first: carnivorous behavior or the loss of the T1R2 protein? With regard to the gene, is this a case of use it or lose it?" This is the guy I heard. During the long interview, he said something along the lines that an omnivirous animal that lost the sense of taste for sweet would be pushed into pure carnivirous. But he could not know for sure.
Post #216,397 by Andrew Grygus 7/25/05 9:30:34 PM Reply	And his 'case of use it or lose it?' is what . . . . . makes sense in an evolutionary context - unless you can come up with a survival benefit from not being able to sense sweet for a hypothetically omnivirous proto-cat. I think that'd be hard. [link\|http://www.aaxnet.com\|AAx]
Post #216,401 by ben_tilly 7/25/05 10:00:56 PM Reply	Don't rule it out I can imagine a situation where a proto-cat was omniverous but would be better off being a pure carnivore, and this was the adaptation that pushed it to be a pure carnivore. Why might that happen? Inventing something off of the top of my head, what if the proto-cat lived in an environment with a sweet fruit around that was bad for cats. An adaptation to make them not be tempted could then be adaptive, with the side effect that they became purely carnivorous. The odds are against this particular theory. Atrophying is more likely. (The fact that many other species have specialized in being carnivores without such an adaptation is evidence that my "just so" story is unlikely in the real world.) But the scientist is correct to say that we don't know whether we're looking at a cause or an effect. Cheers, Ben I have come to believe that idealism without discipline is a quick road to disaster, while discipline without idealism is pointless. -- Aaron Ward (my brother)

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