Evolution

9 Pages 2331 Words

s in an evolutionary fight from which only one would ultimately survive. Then came yet another species that would compete for survival. Neanderthals simply represented the most recent version of the contest. While we may find it bizarre to share our world with another human species, the fact that we’ve been alone since the Neanderthals vanished some 30,000 years ago.

The notion that multiple human species are the norm, not the exception, has only got stronger with a series of major scientific discoveries. Since 1994 , four new species of hominid have been added to the human family tree, with the latest announced in April of 1999. These date from 800,000 years ago all the way back to 4.4 million years ago.

Scientists have also dug up new fossils of know species. This should help them trace the complex relations among our ancestors. One skeleton found in April 1999, suggests that modern humans and Neanderthals may even have mated successfully. And new evidence of stone-tool use, dating as far back as 2.5 million years, has given clues to how our fathers thought and behaved.

These discoveries not only further confirm that multiple hominid species are the rule but also bring us much closer to understanding the ultimate mysteries of human evolution: What were the changes that led to modern humans? When did these changes take place, and why? And perhaps most interesting, will we continue to grow and change. All signs show we are growing and changing, just take a look at athletes getting bigger, stronger, and faster as world swimming and track records fall in almost very major event.

As recently as five years ago, all that scientists could really tell about our earliest ancestors was when they first appeared. Molecular biologists had measured the differences between human and chimpanzee DNA then averaged the rate of genetic change over time. By calculating backward, they determined that great apes a...