what are the theories about the origin of the man?

Answer 1

Origin of man... I assume that you are not meaning the dispersal of Homo sapiens but are questioning what hypothesis there are regarding the beginnings of hominids. The earliest hypothesis put forth to explain this was the savanna hypothesis, which became discredited when the archaeological record of hominids showed sites previous to the time of savannas being the primary landscape feature in Africa, namely sites that preceded 3 mya (million years ago). Archaeology at this point has even unearthed a few hominid sites that are proposing that early hominids were present even as far back as 6 mya, and if this is the case then the savanna is truly an impossible environment to have allowed our evolution. It was Raymond Dart who first proposed the savanna hypothesis and he did so because he had discovered a significan number of hominids that had lived in South Africa. The archaeological evidence for his site proposed a savanna environment. Being one of the first hominid sites to be found, he was free to conjecture whatever ideas he saw fit from his evidence and hence the birth of the savanna hypothesis. Over the last 25 years, as the savanna hypothesis has been increasingly discredited because of the discovery of sites that date back to earlier times that did not have a savanna environment. With this contemporary anthropology has more and more began to describing our evolutionionary environment as being that of a mixed hypothesis, which is a primarily arboreal environment with savanna patches between forests. As some Chimpanzee groups live in this "mixed" environment, whereas Bonobos live in a swampy/arboreal environment and display much more incidences of bipedalism, it is my humble opinion that the mixed hypothesis is also flawed in its reasoning, yet that is where anthropology stands on the subject. Other contending hypothesis for the origins of man are:

The ice age hypothesis, which states that Northern Hemisphere ice ages made the African environment drier suddenly, thus forcing the rapic evolution of our species.

The arboreal hypothesis, which states that our constant tree climbing allowed for the adoption of a more upright posture. There are a lot of arboreal monkeys/apes however which are by no means showing the same tendancy so I don't buy this one.

The hypothesis of neotony, which simply states that some undefined rapid environmental change pushed our ancestor towards more generalized neonatal characteristics (baby characteristics) in order to expand our biological toolkit for adaptation.

And my personal favourite, the aquatic hypothesis, which does NOT propose that our hominid ancestors swam in the open ocean as many of it's opponents will have you beleive. In fact their is a lot of geological evidence that shows that the great rift valley flooded around 8 mya and that this would have resulted in an island remaining in Eretria. The aquatic ape hypothesis postulates that the monkeys that were in this area were forced together onto this Island as the water rose during this period of flooding and as the population became too dense for the remaining terrestrial resources to support this population of monkeys, they began to experiment with new food sources. Over the years one food source that became more and more abundant were the shellfish in the adjacent tidal areas and it was these resources which these monkeys began to exploit (like the crab eating macaques do in South East Asia). As this environment was exploited more and more as a food source, the most successful monkeys were the ones that had advantages (ever so slightly) towards holding their bodies erect as they searched for crabs or oysters (excellent protein source for brain development) in the tidal regions and over many generations (about 1 million years of isolation) bipedalism, a reduced size of our hair, the ability to control our breath, increased fatty tissue, a diving reflex and a whole host of other characteristics came about in these now early hominids. Similiar adaptations took place in a whole bunch of other fully aquatic mammal species like seals, dolphins and whales. The difference with hominids, however, was that the waters receeded after we had only made a partial adaptation towards aquaticism, and as of such they were suddenly left with a new set of characteristics that could be applied within the terrestrial environment where these hominids now found themselves. If these characteristics were not beneficcial then hominids would have gone extinct then and there, but as history has proven, this little, naked hominid stood the test of time and was able to apply his new biological toolkit to adapting to new environments throughout the globe.

So these are the proposed hypothesis regarding the origins of man, and I can't wait until more archaeology is done in the danakil hills of Eritria, and hopefully somewhere there were the conditions appropriate towards preservation so that just a few of our earliest hominid relatives can be unearthed thus allowing this hypothesis to spread throughout the archaeological/anthropological community and dethrowning the old-boys-club of archaeology who are ardently holding onto this ridiculous "mixed" hypothesis simply because their life's work has been put towards ideas that depend on it and they don't want to feel like they wasted away their careers. (interestingly enough the old-boys-club which preceeded the current one fought intensely against the "out of Africa" hypothesis being proposed by Raymond Dart and even created the Piltdown hoax to slow the truth from emerging until after Dart's death) Move on and stop creating barriers towards the other hypothesis and the expansion of academic thought in this area. I say this because in the vast majority of undergraduate courses the ONLY perspective which is addressed is the savanna come mixed hypothesis and none of the other hypothesis are even mentioned. Teach these kids how to think! If the theories are wrong then the evidence will prove it and the hypothesis will fade, but do this without bias you old-school anthropolgy hypocrits!

Answer 2

The newest one is the Serial Endosymbiosis theory, or Symbiogenesis, which implies that our body is made of a collection of bacteria and viral DNA that have combined together to form complexe life forms like us...
Actually this new theory has a very good momentum, after it has been found out that 41% of human DNA was coming from Viral sources...

Answer 3

What method developes our knowledge about this? The creationist theory only has substance when looked at as a moment in evolutionary reality.

Answer 4

enough with all theories, please. In case you have not noticed, this is the information age of finding "all" things that were meant to be discovered long before those {SNAKES} slid their way in the {MASTER'S} [HOUSE] and then swallowed great pieces of genetic codes to disprove any one who questioned the lessons of a false god.

Answer 5

big bang, creationism, evolution, etc