Is microevolution improbable?

Question

If microevolution (descent with modification within species) is possible (and not only possible - observed and proven) then why is macroevolution considered "improbable"?

What is the process that stops microevolution once one line of descendents of an organism become too different from another line of descendents of the same organism?

(Asked in Religion and Spirituality to follow on from an earlier question and its responses)

http://answers.yahoo.com/question/index;_ylt=AhIr2htEWsImpA7WkGtvDHvsy6IX?qid=20070818202343AAWeC0l

Arnon, your answer seems to assume that microevolution is simply the change in frequency of already existing genes. It isn't. It includes changes (mutations) to genes, including the development of completely novel genes.

Answer 1

Good question. Claiming to accept so-called microevolution but not so-called macroevolution is like saying "I accept the concept of days, but I reject the concept of years". One is simply the accumulation of the other.

Common sense dictates that if a population of organisms changes in a few small ways over a few thousand years, then they will change in a few thousand small ways over a few million years. And who could rationally insist that two organisms that differ from each other in thousands of ways could possibly be one and the same species??

Answer 2

Because what you refer to as microevolution is really adaptaion and natural selection. It is the shifting of dominant an recessive traits in response to survival and reproductive selection.
This has been observed in a manner of speaking. Dogs for instance. Varied though the differing breeds are they all can still interbreed. When a line of dog which is self reproducing and cannot interbreed with another line and produce viable reproducing offspring you will then have a different species. You will then have produced the first observable macroevolution that is documentable. All you need to do then is duplicate the effort. That would prove the event was not a one time occurence. Remember please, this is a scientific idea requiring scientific analysis and procedure. To accept a hypothesis or theory as fact because you wish it to be or it makes more sense is fine if it is your religious view, but that does not suffice for the inarguable position of Scientific fact.

Answer 3

There has been no evidence of stable states between cells and formations of life like fish. If that were possible, the cell would've formed into a fish organ in a matter of hours. Any state between that and the organ would be useless.

Evolution is based on the theory that time and proteins formed cells, and that genetic mutations are the cause of macro evolution. Nearly 100% of all mutations have been deemed "harmful" to species, and that's ANY kind of species. I mean, sure there are some rare mutations like the one of muscle dog here - http://www.flickr.com/photos/11646681@N02/1154157275/ - but that just modified muscle mass, and it didn't create anything useful.

There's also been studies about animals like dolphins, porpoises and whales. They tried to duplicate their ways of sonar with all the advanced techology. And even if they could, does something that complex sound like it can be formed by time?

Evolution has a few good points, but the reason why Creationism is scoffed at is because it's a religious thing, and all non-Christians have widely accepted evolution as a valid theory w/o looking at its major flaws. If humans really want to see something as something else, they will.

Answer 4

I have never heard of these terms before. "Evolution" is a term which means a change which takes place over a long period of time. Adding "micro" to the beginning of that word just makes no sense. Unless you are talking about the evolution of microscopic beings, which I think you are not. A great deal of good will can be had with clarity. I hate it when people screw with language. The opposite of "evolution" is "revolution" (change brought about swiftly) and in this way, you can tell that putting "macro" (which means "big") and "micro" (which means small) makes absolutely no sense and muddies the arguement from the beginning.

My respect for Americans goes down when the English language gets bastardized.

Answer 5

Evolution simply means change. We are all created with the ability to adapt to our environment, and that's because our God is not stupid. He knew we would need to be able to adapt to the harsh earth outside of Eden. "Microevolution" is nothing more than animals and humans adapting to their environment. It's not progression toward some goal, it's just adaptation to fit the environment - whatever environment that may be. What Darwin proposed, however, was nothing that was ever observed in the natural world, and therefore it was not scientific. It was speculative. It was a leap of faith.

Answer 6

No more improbable than gravity: as you said, demonstrated.

Creationists have also tried using fairly radical "microevolution" to explain how you could fit each genus on the ark. Of course, there are still to many varieties of life to fit at that level, and they require evolution to be faster for that scenario to work.

Thanks for the nice follow-up.

Answer 7

Macroevolution is just microevolution amplified.

They are one and the same basically. The two terms are pretty useless.

Answer 8

Look at it this way: Dogs come in every size and color and shape but they're all dogs. When a dog gives birth to kittens they you'll have evidence of macroevolution

Answer 9

Debating evolution is out, debating intelligent falling replacing gravity is in dear...