Wednesday, August 8, 2012

Mysterious facts in the History of Human Evolution

Human beings are unique and full of mystery in the life on planet earth. How do humans evolve? Measures what comes first? Why humans evolved in this way and not the other way? Why are we the only human species are there? What humans may have decreased the quality of the evolved?
And is there any guidance that allows human beings to leave planet Earth? The following is the text of Charles Q. Choi, LiveScience Special writer who translated freely in order to provide benefits for those who read it so it adds insight into the true man. 
 
Where did Modern Humans originate?
One theory Suggests That the migration paths taken by modern man as he colonized the world. 60.000 years ago began in Africa. Credit: Max Planck Institute for Infection Biology
The most frequently debated questions in human evolution is a scientific discipline from which modern humans evolved. Hypotheses Out-of-Africa states that modern humans evolved in relatively new in Africa.
Then spread throughout the world and replaced archaic human population has ever seen. Multiregional hypothesis argues that modern humans evolved over a large area of ​​ancient human populations in different areas to mate with each other so that the spread to some tribes that subsequently result in the evolution of modern humans. At the moment the hypothesis Out-of-Africa into a handle and a reference in the theory of modern human evolution but the supporters of the multiregional hypothesis remains strong in his views.

Who is the first hominids?

Analysis of a partial skeleton of a female nicknamed Ardi Ardipithecus ramidus, a hominid That discovery predates "Lucy."  
Credit: © 2009, JH Matternes.
Scientists are uncovering more and more ancient hominid at all times. This means that two-legged creatures, including humans, the direct ancestors and closest relatives. The scientists trying to find the first man to help answer the most fundamental questions in human evolutionary adaptation that is what humans do, and how did this happen?
 
Do we have sex with Neanderthals?

Credit: Michael Hofreiter and Kurt Fiusterweier / MPG EVA
Are we married each other? Does our species have the rest of us of any gene of an extinct cousin? Scientists suspect that the Neanderthals did not die but may be absorbed into modern humans.

Why did modern humans spread its wings out of Africa about 50,000 years ago?

Credit: Stockxpert
Around 50,000 years ago, modern humans out of Africa spread its wings, spread rapidly in most areas of the world to colonize every continent except Antarctica, and even reach the most remote regions Pacific Islands. Some scientists suspect this migration is associated with mutations that alter our brain, which leads to a modern, complex use of language and the use of the tools are more sophisticated, art and society.
 
Is the hobbit?

Artist's rendition of Homo floresiensis.  
Credit: National Geographic Society / Peter Schouten
'Hobbit' is a nickname given to the tiny skeleton found on the Indonesian island of Flores in 2003. Hobbit is actually an extinct human species. Is simply called Homo floresiensis? Whether this framework is only an example of Homo sapiens disabled? Are they a different species from us, but maybe not extinct human species and an integral part of the chimpanzee? Solving this mystery could help shed light on the radical path of human evolution may have occurred.
 
Is there acceleration of human evolution?

Credit: Stockxpert
Recent evidence suggests that humanity is not only growing, but actually accelerating human evolution up to 100 times historical levels after the spread of agriculture. Some scientists say that it remains difficult to ascertain whether or not a particular gene actually grow and stand out because they offer some adaptive advantage. However, if the accelerated human evolution, the question becomes why? Diet and disease may provide the pressure that causes people to change.

Why are our closest extinct relatives?

Credit: NASA / JPL-Caltech
About 24,000 years ago, the species Homo sapiens do not live alone in the world because of our closest relatives are the Neanderthals, (Homo neanderthalensis) were still alive. 'Hobbit' found in Indonesia might also have been a member of the genus Homo, and it seems to last up to 12,000 years ago. So, why do they die and we survive? Whether infection or radical changes in the environment that kill them? Or do we make changes to species farther than they? There is some evidence for both scenarios, but there is no agreed conclusion.
 
What happens to our hair?

Credit: Matthew Bowden
Human hair look unique at the time naked than hairier cousins ​​the apes. So, why nudity is evolving? One reason is that our ancestors shed their coats in order to stay afloat while adventuring in the hot African savanna. Loss of thick fur helps liberate humanity from the spread of parasites and disease infestations. One idea that did not show nudity ordinary human ancestors evolved after adjusting his life in a more efficient use of water.
 
Why do humans walk on two legs?

A slice from a used computer models to show how early Humans may have Walked.  
Credit: Bill Sellers / University of Manchester
Human ancestors evolved with good upright posture before the brain to grow larger or stone tools appeared. The question is why people are standing and walking on two legs when his cousin was caught monkeys on four limbs?
Is realized as two-legged creature actually uses less energy than moving crawling with four limbs. Freeing the arm has allowed our ancestors to bring more food. Stand up straight helps people better control the temperature by reducing the skin is directly exposed to sunlight.
 
Why human brains grew up?

Human brains are about three times as large as Those of our Ancestors That early australopithecines lived 4 million to 2 million years ago, and for years, Scientists have wondered how our brains got so big.  
Credit: NIH, NIDA
There is no question that the large human brain has provided a tremendous advantage in the world. But the human brain is the organ that is very expensive, takes only about 2 percent of body mass and use more than one-fifth of the energy body. Up to about 2 million years ago none of the ancestors of humans have larger brains than monkeys when compared to body size. So what drives a bigger brain?
One possibility is that the growing intelligence that helped our ancestors to make better tools. In addition a large brain to help people interact better with others. May also require radical changes in the environment of human ancestors related to changes in the world.