Why is paleontology important in the study of evolution ?
Paleontology is the study of fossils. Paleontology has played a key role in developing the theory of evolution.
The study of fossils has shown that the animals and plants of prehistoric times were very different indeed from the animals and plants today.
By reassembling fossils bones, scientists can get an idea of the size and shape of the creatures that inhabited the Earth before the appearance of humans.
Teeth and shells that have been fossilized also tell us much about the lifestyle of these creatures. Fossils of insects are often found embedded in amber, which is the transparent rock nodule formed when the resin from trees petrifies. Small creatures are sometimes trapped inside the amber, and are perfectly preserved to give us a glimpse of ancient insects.
Trace fossils are also important in the study of evolution. Trace fossils are tunnels, worms casts and tracks that animals have made on soft sediment that has later hardened into rock. These imprints of animals on the move reveal much about the lives of ancient species including their size, gait, stride length, and speed.
How are fossils formed?
Fossils from when an animal or plant dies in water nearby places. The water insulates the remain from many of these elements that contribute to decomposition. For example, when an animal has died of old age at the bottom of sea, bacteria consume the soft body parts , but leave the hard exoskeleton intact. As time passes, sediment bury the exoskeleton. As the sediments continue to pile on, the lower layers on top. Over time, this pressure turns the sediments into rock.
As the continental plats move around the Earth, crashing into each other, mountains are formed.
Former sea floors are lifted up, and become dry lands. Thank to the movement of the plates, fossils will come closer to the surface, and nearer to discovery by some fortunate fossils hunter. Fossils are finally revealed through the force of erosion.
Though there are millions of fossils that have been discovered, fossilization is a rare occurrence. Soft bodied animals and plants that have nowoody parts are rarely fossilized.
what is the Archaean period?
The Archaean period lasted from 3800 to 2500 million year ago. The Earth was still about three times as hot as it is today, and most of its area was covered with oceans. The Earth atmosphere was mainly carbon I oxide, with very little oxygen in it. Land was beginning to form as volcanoes that emerged from the oceans. The forming of the continent also began during this period, probably as lava flow under the ancient oceans.
They can be found in Archaean rock formation of Western Australia.
So to sum up, the Archaean period was a time of continent-building, and the first stages of early life can be traced back to this period.