Question

Please be thorough and detailed and cite sources please.

Describe BRIEFLY the characteristics of the key fossils that have contributed to our understanding of human evolution.

Answer 1

Fossils tell us when organisms lived, as well as provide evidence for the progression and evolution of life on earth over millions of years. Fossils are important evidence for evolution because they show that life on earth was once different from life found on earth today.

Scientists have discovered evidence concerning human evolution , and this evidence comes in many forms. Thousands of human fossils enable researchers and students to study the changes that occured in brain , body size , locomotion , diet , and other aspects regarding the way of life of early human species over the past 6 million years. Millions of stone tools , figurines and paintings , foot prints , and other traces of human behaviour in the prehistoric record tell about where and how early humans lived and when certain technological innovations were invented.

Study of human genetics show how closely related we are to other primates . Advances in the dating of fossils and artifacts help determine the age of those remains , which contributes to the big picture of when different milestones in becoming human evolved .

From skeletons to teeth , early human fossils have been found of more than 6,000 individuals.Our genes offer evidence of how closely we are related to one another and of our species connection with all other organisms. The human family tree shows the various species that constitute the human evolutionary family.

Before about 1980 it was widely thought that distinctively hominin fossils could be identified from 14 to 12 million years ago . However during the 1970s geneticists introduced the use of molecular clocks to caluclate how long species had been separated from a common ancestor . The molecular clock concept is based on an assumed regularity in the accumulation of tiny changes in the genetic codes of humans and other organisms, use of this concept , together with a reanalysts of the fossil record , moved the estimated time of the evolutionary split between apes and human ancestors forward to as recently as about 5 mya .

The distinctive mark of hominini , the lineage that includes humans and their direct ancestors , is generally taken to be upright land locomotion on two legs . The skull does not indicate with certainty if this species was at all terrestrial, although the fairy forward position of its foramen magnum ( the hole through which the spinal cord exists the braincase ) may suggest a habitually upright posture . The most remarkable aspect of this skull is the broadness and flatness of its face - something previously associated with much more recent hominins - in conjunction with a smaller , ape - sized braincase . This speciman also has small canine teeth compared with those of apes, thus aligning it with the hominins in an important functional regard.