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Re: From the ground up flight: anecdote



On 4-Sep-08, at 10:26 PM, Allen Hazen wrote:

Boehm wrote:
IF birds evolved from the trees down - as flight got better, I would expect
to see tree climbing abilities getting worse, as flight would become the
prefered method of getting up

Um... Why, exactly? If that's the case, why are leopards so adept at climbing trees as opposed to their smaller, presumably insectivorous ancestors?
Besides the fact, I'm pretty sure the ancestors of flying birds missed the 'memo' stating they could only do one or the other, as the from the ground up & trees down groups argue. The simple fact that the argument ever started should obviously point out the fact that they are mutually plausible theories.


I don't know about trees, but I have seen a (domestic) parrot whose
preferred way of getting from the floor to the back of a chair was to climb
sideways up the supporting pole of a floor lamp (grasp pole with both feet,
extend upper foot upwards, bring lower foot up close to it, repeat) to get
to the top of a table, walk across the table, then jump to the chair.

So basically if you increased the distance between the chair & lamp, you'd have reason to retain both abilities.. You could argue that once "full-powered-flight" capability is reached, climbing would not be primarily selected for. That is, of course, assuming, said species is not perfectly fine in it's existence not progressing to full-flight..