TagliatelliMonster
Well-Known Member
It is also funny when evolution is called a theory but in fact it is just a hypothesis.
No, it's not. Evolution is a theory. And a very solid, very well established one at that. It is even perfectly fine to say that it's probably one of the best established, most solid theories in all of science.
Given how well the eye is documented etc, have we done anything that can make evolution of eye hypothesis testable, verifiable and repeatable?
The evolution of the eye can be tested, just like any other aspect of evolution can be tested: by looking at the nested hierarchies in all of life: by comparing the anatomy and the DNA.
And it always exposes itself as a nested hierarchy, which is 110% in support of evolutionary history.
Common ancestry is a genetic and anatomical fact. People seem to forget that.
Here's a simple test you can do... Humans have a blind spot. This is because in the common ancestor that first evolved its "primitive" eyes, all the wiring was in front of the light-sensitive cells. These eyes were so primitive that they could only capture light and dark. Which was better then nothing, so it stuck. What also stuck, was the fact that all the wiring was in front of the cells... This caused a blind spot in all its decendents, which includes humans.
Sight evolved multiple times independently. So there are quite a few different "eye designs" out there.
So, here's a testable prediction: ALL organisms that find themselves on the branch of humans and which share the ancestor in which that "backward" eye originally evolved, will have a blind spot. This branch / nested hierarchy will be completely consistent with other aspects/features in that particular bloodline.
IN OTHER WORDS: find me a species of said branch of life that does NOT have this blind spot, and you will succesfully blow a serious hole in evolution theory. Good luck.
What's the explanation of the era of rapid evolution (while evolution is supposed to be slow)?
Are you talking about the cambrian explosion?
Just for your interest, that period of "rapid" evolution, is only "rapid" in terms of geological timescales. This period actually lasted some 80 million years. So, not so "rapid".
Anyway, there is nothing that states that evolution MUST be 'slow' (again: in terms of geological timescales).
It is rather expected to be slow, simply because of the nature of the process.
Because for a single change / mutation to spread throughout the population and become "fixed", as they say, that by itself already takes quite a few generations.
Then there's also the concept of reaching a "local optimum". Which means that given stable selection pressures, a species has achieved its "perfect" form. Quotes, because "perfect" here is relative.
When the environment/habitat changes (this can be climatological or it can be due to migrating species or whatever), then the selection pressures also change and the achieved local optimum might no longer be a local optimum.
Periods of "rapid evolution" likely go hand in hand with rather "drastic" environmental changes.
At that point, a species either adapts fast to the new world, or it goes extinct.
Most go extinct.
That extinction again drastically changes the habitat. It messes with the food chain and the overal eco-system. It frees up niches that can now be filled by other species. It lowers competition, so it gives extant species more "options". This in turn can also cause more "rapid" evolution. This will continue until there is a new-found balance in the arms-race known as evolution. Until new local optimums have been reached. And so it continues. And so it will continue for as long as there are organism reproducing with variation and competing over limited resources.
It's an inevitable process.
Upvote
0