IW,
Your questions are extremely basic and show a complete misunderstanding of evolution. I suggest reading a good book so you can put your misconceptions to rest.
Why is it there are no interspecies?
What? Species is an arbitrary label made up by humans. We are all 'interspecies' in a manner of speaking (at least populations are)because life continues to evolve. Remember: Evolution works on populations NOT individuals.
Why are there today no chimpanzees that are in various stages of evolving into humans? Why are there today no chimpanzees that are in various stages of evolving into humans?
Do you think we came from modern apes? You have a gross misconception of Evolution. Chimpanzees are fine for their environment niche. They don't have any pressure to become human (whatever that means). They have other qualities that are superior to humans, such as their strength. Chimpanzees are still evolving, though, but for a Chimpanzee to evolve into a human is probably as likely as a Chimpanzee evolving into a fish.
Why are there no sea creatures with rudimentary legs and lungs, attempting to venture onto land?
Are you sure there are none? Ever heard of amphibians? Lung fish? In fact, we know that sea creatures did venture onto land and then some actually went back again to the sea (e.g. whales, dolphins, etc.)
If evolution were true it seems to me we should have partial humans still evolving, pre-humans who have evolved enough to stand erect, speak and have the ability to make rudimentary tools but are less human than the rest of mankind.
What advantage would a less advanced human have over an advanced one? Do you realize that 99% of all species that have ever lived have gone extinct? Extinction is no a rare event. That's the way evolution works. Populations either evolve to exploit their environmental niche or they die out. That is what we find in the fossil record and that is why you don't still see primitive pre-humans. They couldn't compete.
In Fact, not too long ago Neandertals and Cro Magnum man lived together for a while, but the Neandertals could not compete, so they died out. When two species are competing in the environmental niche, then one will always win out since one will almost always have an advantage over the other. The less advantaged species will eventually die out.
Why have the transitory species disappeared?
See extinction above.
Natural selection does not answer the question because every change was due to some advantage yet the previous species which really should have been wiped out because of some weakness was not wiped out, but the newly changed transitory creature which supposedly changed to adapt WAS wiped out!
Yes it does. Evolution is not a linear succession of species. It is a bush - a family like you and your uncles and cousins. Species can split due to environmental pressures or isolation. It does not necessarily follow that the root species will go extinct right away, though the root species will also continue to evolve, so in a sense it will go extinct after a while, in a manner of speaking.
I suggest you read some introductory works on Evolution so you can work out some of your glaring misconceptions. Richard Dawkins has some good books for Evolutionary newbies.
rem
"We all do no end of feeling, and we mistake it for thinking." - Mark Twain
