Here is another example: "One of the textbook examples of evolutionary biology is the long-necked giraffe. The evolution of the giraffe's long neck occurred so that the animal could reach leaves in taller trees. But it's even more complex than that, because the more adaptive aspect of the neck evolution occurred as a result of the giraffe's long legs. Since giraffes do not bend their knees to drink from a pool of water, they require a long neck that can reach all the way down to the water. The neck of the giraffe is used for many purposes, including spars between males."
An animal or plant species becomes better fitted to its environment as the result of natural selection's acting upon heritable variation.
Hypothesis # 2
Life forms are fitted to their environment because they were brought into this world with those traits and functions already built into them, for a purpose.
Berkeley Education website statement:
"Natural selection involves genetic variation and selection among variants present in a population. ...Genetic variation is generated by random mutation - a process that is unaffected by what organisms in the population want or what they are 'trying' to do. Either an individual has genes that are good enough to survive and reproduce, or it does not, but it can't get the right genes by 'trying.' "
Natural selection has no intentions or senses; it cannot sense what a species or an individual "needs." Natural selection acts on the genetic variation in a population, and this genetic variation is generated by random mutation - a process that is unaffected by what organisms in the population need.
How did they survive until they formed those valves in their necks through a long series of random, chance, accidental mutations that just happened to be beneficial? Does that sound like good logic?
Did that happen through a series of random, chance, accidental mutations that just happened to be beneficial? To test this hypothesis, a good question might be: "Which evolved first: the long neck, the shut-off valves, or the special ability to pump blood all the way to the brain?"
Much of the clip art on this site is courtesy of Phillip Martin.