We share about 95% of our genes with the Gorilla, and 50% with a banana!
Faced with those numbers most people would answer that it's something to do with evolution.
The theory of evolution has had a powerful effect on our views of the world!
It has also caused great debates since the 1840's when Darwin first suggested evolution. Even today scientists still debate this important scientific idea.
This theory is basically that all animals and plants on Earth gradually developed, or 'evolved', over millions of years from a common ancestor.
Life first began as simple organisms living in water. From there organisms became more complex and gradually moved onto the land and all over the Earth.
The process took only about 3 billion (3,000,000,000) years. Only!
Fossils provide a lot of the evidence on which the theory of evolution is based.
They show how organisms that exist today have altered over millions of years from the simpler forms shown in fossils.
One famous series of fossil examples is that of the supposed evolution of the modern horse. The following diagram shows four of the ancestors of the modern horse
You can see how the animals get larger as time, and presumably evolution, goes on. Initially the animal was about the size of a dog but ends up being much bigger.
Also the bones of the fore leg change from being three separate bones into being one large bone with the hoof of today's horse on the end.
However fossils are 'flukes'. We have only got fossils when an animal or plant died, fell into a suitable substance and then didn't decay quickly.
Most animals or plants at that time would have died where they would decay quickly. In that case we would have no fossil!
Although most scientists and people now accept evolution there are some problems with it.
The pattern of evidence we have with fossils is not complete, there are "missing links" in that chain of evidence.
The link between humans and our ancestors is still incomplete.
Archaeologists and Biologists are continually searching for more evidence to support this theory.
So this is still an area where lots of work needs to be done. Fossils and evolution theory is not a dead subject. Perhaps you will add more to them yourself in the future.