Re: From the ground up flight: anecdote

[Amtoine Grant <rascienz@shaw.ca>]

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..