Is this a good explanation?

Question

Okay. Lets say you have Adam the Ur-rodent and Eve the Ur-rodent after the "Flood." They have a bunch of baby Ur-rodents, who have a bunch of baby Ur-rodents and so on and so on and so on.

After a while, some of these Ur-rodents go to the Americas and some go to Africa. They lose track of their distant cousins and go on having generation after generation of happy Ur-rodents.

Now, the Ur-rodents in the Americas learn to climb trees and eat acorns and stuff. They like the lush green forests and their claws become longer and sharper so they can climb with more dexterity. Their tails become agile and quick to help them with balance and long claws and agile tails are now attractive features in a mate because they will help the babies survive.

And the Ur-rodents in Africa learn to conserve water and eat grubs and they learn to sleep through the long hot days and to do their running around and foraging at night. Their eyes become big so they can see at night. Like the long...

...claws and agile tails of their American cousins, the big eyes and grub-grabing tongues become attractive to the African rodents.

After many many generations, the Ur-rodents of American and the Ur-rodents of Africa are very very different. The babies are really very much like their parents, but are they much like Adam the Ur-rodent and Eve-the Ur-rodent? No. Not at all. So now we have two SUB-SPECIES of Ur-rodents.

Many more generations later, if they happen to run into each other, they could still breed with each other, but their offspring is infertile - like the Lyger and the mule. BINGO! that means they are separate species! "MACRO-EVOLUTION." Ur-rodent Africanus and Ur-rodent Americanus.

The mechanism would be genetics. If a trait becomes desireable, those with that trait are more likely to breed and pass the trait to their offspring. Yes, the rodents will still be like their parents, but if you go back thousands of generations, they will be very different from their great great great great great great great great great great great great great great great great great great great great great great great great grea great great great ad nauseam grand parents

simonT - thanks. The ring species, which I have never heard of, is a GREAT asset to the argument. The biggest problem I see preventing people from understanding evolution is that they seem to think that one day an ape gives birth to a human child, but this ring species explains the blurred line between "new" species.

I know the flood never happened, but it's a good way establish my Ur-rodent. :-)

Thanks, emfererin. Good point.

Answer 1

No.

Because the flood never happened.

However, what you are talking about is a ring species. There are examples of this:

http://en.wikipedia.org/wiki/Ring_species

Answer 2

No, you assume that the breeding will take place outside of the original sub set, rather than within the sub set, but only to those with the most desirable traits. Ur-Africanus won't mate with another species of rodent (cross breeding), but the males (or females) will breed with those other Ur-Africanus rodents (in-breeding) that are able to survive due to abnormally large eyes and large tongues. It's not macro-evolution (one species to another), but mutation (changing what you've got to live easier).

BTW
Checked out the Wiki page and it even says;

"The problem, then, is whether to quantify the whole ring as a single species (despite the fact that not all individuals can interbreed) or to classify each population as a distinct species (despite the fact that it can interbreed with its near neighbours). Ring species illustrate that the species concept is not as clear-cut as it is often understood to be."

The ability to inter-breed does not therefore conclude that there is a new species, but perhaps only animals that can't breed outside their neighbor.

Addendum;

All of this is Darwinian, survival of the fittest sort of stuff. Darwin never said that over time orangutangs (Ur-africanus) mated with gorillas (some other africanus) and man came to be, but that orangutangs naturally bred out their shortcomings. If what your saying is true, then I couldn't have kids with someone from Asia or Africa because we're too different.

Answer 3

Close.
Except you have the cause and effect backwards.
Just limiting my point to the easiest one, in the case of africans, their eyes didn't grow larger in response to their nocturnal habits.
In your example, it would appear that their genes were such that a certain random expression produced larger eyes. Since larger eyes favored survival in their nocturnal arena, those with large eyes survived while those with smaller eyes were eaten. Over many generations, only those with large eyes lived long enough to pass on their genes and they became purebred.
On another animal, a slightly different genetic structure might have made more rods in the eye, rather than bigger eyes.
But whatever genetic pattern expresses a trait which aids survival in any animal, in the long term it is that trait which consistently gets passed.

Update:
Craig R - stop being selectively DENSE.
Her description IS the "mechanism of evolution" and you damned well know that. You are correct, big eyes on one continent is not a different species from the smaller eyed cousins on another. But environments change, and so will survival traits along with them. as favorable genes come and go, it is not any major "leap of faith" to imagine an ultimate loss of cross-reproductive capability.
And in fact, it's one HELL of a lot easier to imagine than "god musta dun it".

Carol D - The above goes for you, too.

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Answer 4

I think the American Ur-rodents would look like me. Tough and pissed off!

Answer 5

I see a flaw. Your hypothetical Ur-rodent offspring would not "evolve" as you mentioned. The ur-rodent was created as it was and the off-spring of the Adam and Eve ur-rodent would be like them. Their adaption would be external, such as developing tools to allow them to dominate their different surrounds, not an internal adaption to mutate a variation of limbs.

Nice try though.

Answer 6

A good explanation of what?

What is the mechanism of evolution in this case? Things just "become". If traits that enhance survival are merely being selected by the environment, this is not evolution, and the result is not a new species.

Answer 7

good one, and i liked the name Ur-rodents its funny!!!!

Answer 8

it does make a lot of sence at least to me.

Answer 9

no