I do believe in evolution, but I have a question, mainly for my own curiosity.

There are two evolutionary items that happened of which I can't get around my head. Any explanation would be great:


1). Most, if not all birds before the K-T extinction event had teeth. Strong teeth! But afterwards, globally, strong teeth disappeared from the species and all birds could no longer produce the proper calcium for it. Why is it that this was a global evolutionary event, and not selective in one species of birds? Sure, ducks and the like still have remnants of it, but they're crap teeth, and it still doesn't explain why EVERY species of bird evolved this way, globally. It wasn't limited to one specific region or area of change, globally they lost teeth.

And no, it wasn't because of the K-T event, because there are records of most birds still having teeth shortly after, in the mammalian era. But by the time more complex mammals came about, teeth were gone.

2) Why did flowers evolve 'en mass in the Cretaceous. It wasn't limited to one species of plant. A Member of virtually every plant species suddenly evolved flowers: bushes, shrubs, trees, grasses, weeds, and small flowers themselves. It seems odd how ever species of plant had a member of it suddenly evolve flowers.




The reason I ask is simply that it's odd. Usually evolution is within one species, with one common ancestor. But for the above, it happened in multiple common ancestors. And strangest of all, all at the same time (as opposed to the mutation showing up a few times once in awhile until it was viable ie: the flying Triassic feathered lizard with the later-evolved feathered gliding sauropod dinosaurs.)





Please no arguing here, it's a simple question to both sides. I consider my self an evolutionist, so don't call me otherwise.


[edit on 17-6-2008 by Gorman91]

Originally posted by Gorman91
1). Most, if not all birds before the K-T extinction event had teeth. Strong teeth! But afterwards, globally, strong teeth disappeared from the species and all birds could no longer produce the proper calcium for it. Why is it that this was a global evolutionary event, and not selective in one species of birds? Sure, ducks and the like still have remnants of it, but they're crap teeth, and it still doesn't explain why EVERY species of bird evolved this way, globally. It wasn't limited to one specific region or area of change, globally they lost teeth.

I have to run and do something else, but I'll give a quick response...

Why do you think that this happened to all species globally? Why not one or a few more species who eventually diverged to what we see today?

So, we have numerous species of birds with teeth, most die out, one or more lose teeth and diverge (appears to be a developmental change, as the gene can be 'turned' back on). Or various scenarios like this: 100 with teeth, 1 diverges and evolves no teeth (100 teeth, one none), the none toothed species diverges into 20 (100 teeth, 20 none), then all toothed become extinct (20 none), beakies become sole avians (lots).

2) Why did flowers evolve 'en mass in the Cretaceous. It wasn't limited to one species of plant. A Member of virtually every plant species suddenly evolved flowers: bushes, shrubs, trees, grasses, weeds, and small flowers themselves. It seems odd how ever species of plant had a member of it suddenly evolve flowers.

Same here. Why do you think there had to be evolution in every species of plant, rather than a couple of novel early angiosperms (these are the flowering plants)? A new species evolves, is very successful, diverges quickly into new environments.

For example, from studying human fossils we see that at times there was more than one early homo around, but now there is one. Perhaps in 5 million years we'll have 20 (I doubt it, but you hopefully get the gist).

And I don't want to argue. Just wondering why you think that was the case.

[edit on 17-6-2008 by melatonin]

Originally posted by Gorman91
I mean, I don't exactly see small weeds becoming massive treed in such small time when other barked trees took the entire time period from trilobite to mamal-like reptiles to develop bark. And It still doesn't make clear flowering weed-flowering tree relationship lineage, but it goes pretty well.

Not so much a short time though. We are talking on scales of millions of years. It is hard for our puny human minds to comprehend such timescales though.

Got any good explanation on birds?

I mainly interested for my own interests, but I want to also create a 3d spin off of something like natural geographic's extraterrestrial. Might as well learn all I can on life's change.

That's the way to be. You look around consume some information, make some inferences, and test them out. Curiosity is a great thing, not so much for cats though apparently.

If I get some time later, I'll do a little bit of research for you. I really have some things I must do most of today. So later possibly.

melatonin wrote:

1). Most, if not all birds before the K-T extinction event had teeth. Strong teeth! But afterwards, globally, strong teeth disappeared from the species and all birds could no longer produce the proper calcium for it. Why is it that this was a global evolutionary event, and not selective in one species of birds? Sure, ducks and the like still have remnants of it, but they're crap teeth, and it still doesn't explain why EVERY species of bird evolved this way, globally. It wasn't limited to one specific region or area of change, globally they lost teeth.

And no, it wasn't because of the K-T event, because there are records of most birds still having teeth shortly after, in the mammalian era. But by the time more complex mammals came about, teeth were gone.

I would guess that it was no longer an advantage for birds to have teeth, anywhere in the world. So birds with teeth had the same chance of producing offspring as birds without teeth, and the birds without teeth "won".

melatonin wrote:

2) Why did flowers evolve 'en mass in the Cretaceous. It wasn't limited to one species of plant. A Member of virtually every plant species suddenly evolved flowers: bushes, shrubs, trees, grasses, weeds, and small flowers themselves. It seems odd how ever species of plant had a member of it suddenly evolve flowers.

Because dinosaurs -- planteating dinosaurs specifically -- began to eat plants that grew close to the ground. The would-be flowers could grow faster (and therefore become out of reach) than the other plants, and they could also reproduce faster because of their new flower-reproduction system. Basically, it was become a flower or get eaten before you reproduce, and the goal of the plants was to reproduce. You can't reproduce if you get eaten, and you can reproduce really fast if you're a flower.

[edit on 25-6-2008 by nathan_p]