h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I always wonder how the evolutionist theories deal with the following (unless I am wrong in my first assumptions) :

If evolution goes from simple to complex, then a caracteristics like the ability to fly is probably coming later than the ability to walk/crawl ; and I believe it takes more than one mutation/genetic change to go from a non-flying animal like the ancestor of bat and other non-flying related mammals (size and shape of the fingers, hollow bones, the skin in between, adapted claws to grab a branch to land on, etc.).
Apparently, changes in the design of a species do not appear very often, so it is very unlikely that two or more changes appear in the same generation.

So there is certainly a intermediate step where a previously walking mammal started to get very elongated fingers, or skin in between short fingers, or hollow and lighter bones, while still not completely adapted to fly. This poor animal would certainly be less adapted to walk than the non-mutated generation...

In that case, how would such a handicapped creature survive at ground level long enough to carry a next generation ? And the same goes to several generations to follow until all fly-adaptations were finally done ?
And if the intermediate steps did survive, where are they now ?

I am not taking any side here, nor do I pretend to have a full view on the subject, far from it, but this question has nagged me ever since I saw my first bat at the zoo when I was six, and my father was explaining that the bat had an ancestor that had fingers like many other species, and that evolved in the bat's wing.

C.L.

"I always wonder how the evolutionist theories deal with the following (unless I am wrong in my first assumptions) :"

Always good to question your assumptions - good start.

"If evolution goes from simple to complex"

Whoah. Stop right there. Evolution does not necessarily go from simple to complex. Evolution goes from what works, to what work *better*. If what works better is simpler, then it goes from complex to simple.

For example: frogs have a larger and more complex genome than humans. Why should this be? Because frogs lay their eggs in water. A large part of their genome is dedicated to making all sorts of allowances for differences in the conditions in which their eggs must develop. Certain chemical reactions which form part of the development of the tadpole will only work in certain narrow temperature ranges, so there have to be other, backup reactions available which accomplish the same thing that work when the water is hotter, or cooler, or more salty, or more acid, or whatever.

Mammals do not need all that allowance-making software, because the environment in which the embryo develops is entirely controlled and predictable - the womb. By having a temperature/moisture/acidity/etc. controlled environment, mammals are able to dump a lot of extraneous information from their genome. So in one sense, they are *simpler* than amphibians.

Do not mistake "complex" for "complicated" or, worse, "advanced". Is a clock with a thousand moving parts more "complex" or more "advanced" than a digital watch with no moving parts at all?

"then a caracteristics like the ability to fly is probably coming later than the ability to walk/crawl"

'probably'? Use your imagination, or do a little research.

http://animal-world.com/encyclo/fresh/characins/hatchet.php

"and I believe it takes more than one mutation/genetic change"

I'm not sure you even know what you're talking about at this point, and a little knowledge is a dangerous thing...

"Apparently, changes in the design of a species do not appear very often"

Where on earth did you hear that? Changes in the "design" of species appear every time a new member of that species is born. That's what evolution is - that's ALL evolution is. Stuff gets born that inherits stuff from its parents - end of story. (Of course, it's expected that you can infer that its parents were *survivors*, so they've passed on what they can of what it takes to survive).

But what's with this word "design", anyway? Species are not "designed" any more than clouds or raindrops are "designed". They are shaped by their environment, as surely as a river is shaped by the riverbed.

"so it is very unlikely that two or more changes appear in the same generation."

You really do need some biology education. Far more unlikely is that there would be only a single change in a generation. But the point here - and this is the point where the imagination of many religious people falls down - is that the changes we're talking about are really vanishingly small. You don't go from chihuahua to great dane in one generation, or even a hundred. So the changes we're talking about require really, REALLY long periods of time to happen in. Periods of millions of years, periods our imaginations are not built to handle except in the most intellectual terms.

"So there is certainly a intermediate step where a previously walking mammal started to get very elongated fingers, or skin in between short fingers, or hollow and lighter bones, while still not completely adapted to fly. This poor animal would certainly be less adapted to walk than the non-mutated generation..."

Well, yeah...

"In that case, how would such a handicapped creature survive at ground level long enough to carry a next generation ?"

OK, again with the failure of imagination. First of all, why "handicapped"? And second, why would such a creature try to survive at ground level? Surely its adaptions arise because it spends most of its time up trees in the first place?

"And if the intermediate steps did survive, where are they now ?"

OK, by this point I'm assuming you're either
(a) being facetious
(b) being deliberately, wilfully ignorant
(c) just a bit dumb or
(d) eight years old and don't have the Discovery channel or any books.

In response to your question, might I suggest you google the words "flying squirrel" and have a little think?

"I am not taking any side here"

There aren't two sides to this argument. There's reality, and there's stuff people have made up to explain why their fantasies don't explain reality. It's not a debate, really, so there's only one 'side'.

"nor do I pretend to have a full view on the subject"

I think we've established that.

"but this question has nagged me ever since I saw my first bat at the zoo when I was six, and my father was explaining that the bat had an ancestor that had fingers like many other species, and that evolved in the bat's wing."

You're doing the right thing asking questions. Get some good books on natural history. Take a look at the wing of a bird, the wing of a bat, and the wing of a pteranodon. Notice the similarities. Notice the differences. Try to read some *science* books about evolution. They should be able to help you. As a starter, I can highly recommend all three "Science of Discworld" books by Terry Pratchett, Ian Stewart and Jack Cohen.

Good luck.

SoRB

Thanks for helping me shaking my misconceptions.
I'll sleep better tonight, and start some reading tomorrow !

C.L.
PS : for my defense, one can not be a fabulous Drag-Queen, born French, and well versed in all matters of science... Too much blessings spoil the broth !