The past week has been an eventful one for the hypothesis that thermoregulation requirements influence beak morphology, but there is still more work to be done. Peter Grant complimented the studies but wrote in an e-mail that "The hypothesis would be strengthened by a demonstration that fitness (survival) of birds in the wild varies as a result of variation in beak size–related heat dissipation."
Even if the new hypothesis continues to gather support, it does not negate the elegant studies conducted by the Grants or other researchers in the field; diet is clearly a factor that influences beak morphology, Greenberg says. Rather, the new studies emphasize that traits are often the result of compromises between many different factors.
To Thomas Smith, an evolutionary biologist at the University of California, Los Angeles, the growing support for the hypothesis "means we should reexamine a lot of the works we thought were driven by feeding ecology, and think about thermal relationships. I think it would be particularly exciting to look at this in Galápagos."
Greenberg's thoughts are along the same lines. What does he plan to do next? "I'm going to keep working to make the song sparrow the next Galápagos finch," he says.
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Add CommentThe article quotes a Peter Grant email: "The hypothesis would be strengthened by a demonstration that fitness (survival) of birds in the wild varies as a result of variation in beak size–related heat dissipation."
Reply | Report Abuse | Link to thisAs I understand, natural selection favors animals that more successfully reproduce, not those that survive the longest...
@jtdwyer, a bird that survives longer has a greater chance of reaching maturity. Also, a bird that survives longer has more opportunities to reproduce as most organisms are able to reproduce their entire adult lives. Furthermore, organisms that pass memes to their offspring, as many birds do, will have a greater chance of raising their offspring, therefore preparing them for survival, than birds that do not survive as long.
Reply | Report Abuse | Link to thisUltimately it is not your own successful reproduction that is favoured so much as the successful reproduction of your offspring's offspring. If I have lots of children but all my children either die or for some other reason fail to reproduce or fail to produce viable offspring of their own, then I am no further ahead.
@Na g n o s t ic, was there a scientific point you were trying to make or were you just announcing that you are a bigoted idiot? Cause I think we already knew about that bit. Hey, why not hang out on the KKK site? It seems more your speed.
Reply | Report Abuse | Link to thisBeak size may be an adaptation to regulate temperature and conserve water? Yes, this seems plausible, however it does not rule out or diminish the effects of size and shape of seeds. Consideration of both variables is needed for a complete explanation. These hypotheses to explain beak size do not need to be mutually exclusive.
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