No, this is hypothetical and not proven. Common descent is based on a slippery slope that just because some organisms evolved from others, that ALL organisms had to evolve off each other. This then becomes an educated guess, but not scientific fact.
Here's a discussion on some examples of skulls scientists have found, and how they thought they were monkeys evolved into humans, and how it was found out that these weren't really evolved; but simply humans or monkeys. He says:
The argument holds that things who look alike, must have evolved from one another. That is ofcourse uncertain.
Similarity could just as well mean that they were created by the same creator rather then evolved out of the same specie.
The similarity does not prove one belief to be more likely than the other. Also note that the comparisons are usually made in the wrong way. For example, many of the alleged intermediate species between ape and human, are argued to be human afterall. Here are some proposed missing links:
* Australopithecus anamensis 4.2 to 3.9 million years ago
* Australopithecus afarensis 4 to 2.7 million years ago
* Australopithecus africanus 3 to 2 million years ago
* Australopithecus robustus 2.2 to 1.6 million years ago
The false claims from Richard leakey and Donald C Johanson that the australopithecus walked erected has been refuted and it seems the Australopithecus is closely related with urangutans which according to evolutionists is from a different branch then the one mankind origenated from.*
Homo habilis 2.2 to 1.6 million years ago (proposed in the 60's as first humanoid that walked erecte and used tools). New discoveries in 80's showed a different picture and Bernard Wood and C. Loring Brace said that this was in fact nothing more then An Australopithecus habilis. So it's just another extinct african ape.
* Homo rudolfensis 1.9 to 1.6 million years ago. It refers to a single fragmented skull found in Kenia. However most scientists have accepted it again as nothing more then Australopithecus habilis.
* Homo erectus 2.0 to 0.4 million years ago. Although this skeleton is exactly the same as human, evolutionists have classified it as a transendiery specie, based on the small skullcontents (900-1100 cc) and because of the big eyebrows (of the skull). However, there are humans alive today with that skullcontents (i.e. Pygmees), and that have such eyebrows (i.e. Australian aborigenals)! So there is no reason to assume these skelletons are a missing link, they are just humans. In fact the New Scientists of 1998 14 march even wrote an excelent article of how Homo erectus had the technology to build and use transport ships.
* Homo sapiens archaic 400 to 200 thousand years ago. Again there's no reason to assu?me they weren't human, in fact many researchers have even concluded that they are exactly the same as Australian aborigenals. They even found skeletons of them showing that they lived up to recently in villages in Italy and Hungary. The dramatic pictures of hary human-like apes you found in schoolhandbooks are just indulgance into imagenation, remmeber we've only found skelletons.
* Homo sapiens neandertalensis 200 to 30 thousand years ago. Erik Trinkus, paleontologist of university of mexico writes: detailed study of the skelleton of the remains of the Neandertalensis with modern man show that nothing in the anatomy of the Neaderthalensis such as movement, manipulation, intelect and linguistic capabilities are inferior to that of modern man.
Now I'm not going to claim there's some sort of crazy conspiracy going on here, and that evolutionists purposely create false intermediate species. But perhaps people are just looking so hard for these unfound missing links that they start to see things that aren't there.