[berkeleybeej]

You mention logical implications. Here is my logic:
-Offspring tend to resemble parents, tend to have similar features. I think we can agree on that.
-When an animal has a feature that allows it to live a healthier life, it is able to live longer and produce more offspring. We should all be able to agree with this.
-Therefore when an animal has a desirable trait it will pass that trait on to more offspring than another animal without that trait would.
-Those offspring would then pass that trait on to their offspring and so forth and the entire population would eventually gain that trait.

This is evolution. How do you refute these logical assertions?

(This post is from berkeleybeej's son. I apologize for not having my own screen name)

[f.Christian]

Main Entry: log·ic

Pronunciation: 'lä-jik
Function: noun
Etymology: Middle English logik, from Middle French logique, from Latin logica, from Greek logikE, from feminine of logikos of reason, from logos reason -- more at LEGEND
Date: 12th century

1 a (1) : a science that deals with the principles and criteria of validity of inference and demonstration : the science of the formal principles of reasoning
(2) : a branch or variety of logic
(3) : a branch of semiotic; especially : SYNTACTICS
(4) : the formal principles of a branch of knowledge b
(1) : a particular mode of reasoning viewed as valid or faulty
(2) : RELEVANCE, PROPRIETY c : interrelation or sequence of facts or events when seen as inevitable or predictable d : the arrangement of circuit elements (as in a computer) needed for computation; also : the circuits themselves

2 : something that forces a decision apart from or in opposition to reason

[gore3000]

-When an animal has a feature that allows it to live a healthier life, it is able to live longer and produce more offspring. We should all be able to agree with this.

The problem with the above, while it sounds eminently reasonable, is genetics. Now we know that children get half the genes from the father and half from the mother. So a totally new trait would, regardless of how useful it is have only half a chance of being passed on. This is a tremendous problem for evolution.

Now you can say, but wait if the new trait is extremely useful, then the individual will reproduce much more than the rest and be able to overcome this problem and pass it on to the rest of the species. Problem with that is the theory of evolution itself, that all changes are slow and gradual. Such gradual changes cannot overcome the 50% bias against its being passed on to future generations.

However, you might say, but wait, what if evolution does not work that way, maybe it works the way Gould said and we have sudden changes? We have problems then too. Let's say that a lizard suddenly sprouted wings and learned to fly. Now this is an incredibly favorable change which would surely be spread through the species. Or would it? Would a female lizard want to mate with such a monstrosity? I doubt it. Even more important, due to the extreme genetic changes required in such a transformation, would it even be possible for the female to mate and produce winged lizards? Definitely not. So no, anyway you slice it, these new traits will not be passed on.