HumPrint - Human Evolution My how far we've come Where do...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
My, how far we've come! Human Evolution
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Click here to go back to LOM Where do we come from? This broad metaphysical question is one that all humans have probably pondered at one time or the other. It is natural to wonder about the origins of yourself, your family, your country, and all of humankind. In fact the ability to do is one of the traits that is unique to our species, Homo sapiens . It is well established that humans' closest extant (which means not extinct) relatives are some of the Great Apes, the chimpanzees and gorillas. When comparing modern apes and humans, several physical differences jump out at an observer (and I'm not talking about hair distribution patterns!). Apes have larger jaws and larger teeth. They have smaller brains and the opening in the skull that the spinal cord goes through is further back. Ape trunks widen towards the legs, while a human trunks tends to remain the same width. Apes also have longer arms (and no opposable thumbs), shorter legs, and a pelvis unsuited for bipedalism (upright walking on two legs). Paleoanthropologists , scientists who study human evolution, focus on physical characteristics such as these since they are preserved in the fossils. Other traits that separate humans and apes such as complex language and abstract thinking are not conserved as easily in rock. Despite these physical differences, the DNA in humans and chimps is 99% identical. This high similarity in DNA sequence confirms the close relationship of humans and chimpanzees.
Background image of page 2
Click here to go back to LOM As you might expect based on thei rshared characteristics, modern humans and the apes share a common ancestor. The lineage leading to modern gorillas was the first to spilt off while humans and chimps last shared a common ancestor 5-6 million years ago. In making an analogy to a family tree, humans and chimps are not brother and sister with the common ancestor being a parent. A more accurate representation would be that the common ancestor is a great-great-great-great-great grandfather and chimps and humans are two cousins that were born several generations later. In the course of the family history there have been many intervening family members, some of which contributed directly to the evolution of chimps and humans and some that did not. The common ancestor was probably more ape-like since many of the fossils in the human line tend to progress away from the ape-like physical characteristics and towards modern human ones. Paleoanthropologists follow the course of human evolution by studying fossils. Of course, due to deficiencies in the fossil record, it is still an incomplete tale and subject to adjustment as new fossils that shed light on human evolution are discovered. Interestingly the story of human evolution is better preserved than that of the modern chimps. Early in hominid (meaning human-like) evolution, the predecessors of the human line moved to the grasslands where fossils are more like to be preserved. The modern
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/21/2008 for the course BIOL 100 taught by Professor Lee during the Winter '07 term at San Diego State.

Page1 / 9

HumPrint - Human Evolution My how far we've come Where do...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online