WEIT Chap2

What is a fossil?

A fossil looks like a stone, but it is not really a stone. It is a memory of an animal that lived a long time ago. The addition of a time factor and chemical reactions formed it. We will explain precisely how a fossil is formed later.
Hence in fossils, we can see the shape of the body of the organism. This allows us to see how the ancestor of such organism looked like.

Between myths and truth

During the Greek period, people didn't know what these tracks were. This probably gave rise to mythology.

{{co|not essential information} }[[ Utilisateur:Pierre.brawand|Pierre.brawand]] 19 avril 2011 à 22:43 (CEST)
Much later, in the nineteenth century, people thought fossils were made by supernatural forces, results of religious cataclysm or unknown species of far living animals.

How are fossils formed?

The formation of a fossil is called fossilization. It begins as the rest of a dead organism (animal or plant) falls in water or in a wet environment. The organism's body's decompose. As this happens, the rest of the animal is covered by sediments during ages.
The sediments and the bones are transformed in a kind of stone which wears the track of the organism. Erosion and extreme climatic phenomena reveals the fossil. That is why we can discover animals that were born thousands or millions of years ago!

Are fossils easily found?

Fossils can be found everywher e

.

too short. Give examples... [ [U tilisateur:Pierre.brawand|Pierre.brawand]] 19 avril 2011 à 22:43 (CEST)

How can we determine the age of rocks ?

Once fossils are classified, we can see what appeared kind of organism appeared fir s

t.

you need to explain this [[Ut

==Why are fossils important for Evolution study

?==

yes... that's why there is an entire chapter on them! [[Uti l isateur:Pierre.brawand|Pierre.brawand]] 19 avril 2011 à 22:43 (CEST)

Fossils are the evidence of evolution. Without them, we would have only a "theoric" sketch of how species evolved throughout the centuries.

What is the "fossil record" ?

Fossils and birds...
Fossils in the sea...

From the earth to the air

The earlier species at the origin of birds were reptils.

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