# Question About Evolution

**URL:** <https://boards.straightdope.com/t/question-about-evolution/595109>\
**Category:** Factual Questions\
**Created:** [September 3, 2011, 9:33pm UTC](https://boards.straightdope.com/t/question-about-evolution/595109 "2011-09-03T21:33:18Z")\
**Posts on this page:** 3\
**Page:** 2

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**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\
**Post date:** [September 4, 2011, 11:31am UTC](https://boards.straightdope.com/t/question-about-evolution/595109/21 "2011-09-04T11:31:24Z")

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Your argument is similar to the “what use is half a wing (or any eye)?” question.

The answer is, “more use than no wing (or eye) at all.”

Any proto-wing or eye may not be a “small, useless appendage,” but something that enables the proto-bird to escape from a predator better than one without.

And no, half a wing doesn’t mean a full one only on one side, but a partial development in a symmetrical fashion, which is much more logical and likely.

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**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\
**Post date:** [September 4, 2011, 1:53pm UTC](https://boards.straightdope.com/t/question-about-evolution/595109/22 "2011-09-04T13:53:32Z")

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> [@Blake](#):
>
> … their is no plausible path from glider to flyer.

Why is it implausible that a gliding animal might use muscle power to move its wings, with the effect of extending its glide?

> [@](#):
>
> At some point on the path to flying a gliding animals must pass though a stage where the forelimbs are utterly incapable of providing powered flight, yet almost completely useless for climbing as well.

How about the [Hoatzin](http://en.wikipedia.org/wiki/Hoatzin)?

> [@Wiki](#):
>
> The newly hatched bird has claws on its thumb and first finger and so is enabled to climb on the branches of trees with great dexterity until such time as the wings are strong enough to sustain it in flight

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**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\
**Post date:** [September 4, 2011, 3:48pm UTC](https://boards.straightdope.com/t/question-about-evolution/595109/23 "2011-09-04T15:48:35Z")

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> [@Chronos](#):
>
> Well, what **Xema** said isn’t incorrect, though it is prone to misinterpretation. It certainly _is_ possible that flying squirrels might eventually evolve into something like bats. After all, bats evolved in the first place from ancestors that were something like flying squirrels. The key, of course, is that just because it’s possible, doesn’t mean it _must_ happen.

Anything\* is possible, but the question is whether it is probable. Absent a change in the environment, there is no reason to speculate that flying squirrels will evolve into bat-like creatures. Certainly not in the time frame mentioned, and especially given that there are 50 or more species of flying squirrels that have been around for millions of years and none of them has started to look like a bat.

As \*\*Blake \*\*said, we know next to nothing about bat evolution, so we don’t have a good model of going from non-bat to bat.

So, given that this is GQ, if we want to speculate about what is possible, then pretty much any post anyone makes could be called pertinent to the question asked. I think we are better served, in this forum, to concentrate on what we know and leave baseless speculation to other forums.

\*anything that doesn’t violate the laws of physics.

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