charles darwin natural selection by willow sillence

Charles Darwin

Natural Selection

By Willow Sillence

Theory of Evolution

Darwins most famous theory states: “Evolutionary change comes through the production

of variation in each generation and that through the survival of individuals with different combinations of these variable characteristics.”

This means that he believed that animals changed over the years and developed into new species.

He had five theories to explain evolution and he believed they all worked together to create an overall process.

Darwins five theories:

1. Evolution - species come and go through time, while they exist they change.

2. Common descent - Organism are descended from one, or several common ancestors and have changed from this

original stock. 3.Species multiply - the diversification* of life involves

populations of one species changing until they split into two separate species, this has probably happened millions of times on Earth.

*diversification means variety, to spread out, or to change

Darwins five theories continued..

4. Gradualism - Evolutionary change happens through small changes within a species gradually building up and up; new species are not made instantly.

5. Natural selection - Evolutionary changes occurs through variations between individuals. Some of these give the individual an extra survival probability.

Darwin considered these five theories as part of on overall idea and that they all occur together. Scientists however often preferred to believe in one or two of these theories separately and it wasn’t until the 1930s and 19402 that they gathered enough evidence to realise that Darwin was right all along.

Natural Selection• Darwin’s most revolutionary part of his theory of

evolution but it was actually very simple.

• The basic idea of this is that through each generation changing and the survival of the strongest individuals this increases the chance of survival. This then passes on to their own offspring who then also benefit from these better and stronger genes.

• So over time each generation becomes better and these good characters spread through the population.

Natural selection

For it to work it has occur along with lots of other things.

Historians and biologists analysed Darwin's work, for example Ernst Mayr who identified five facts and three conclusions which helped to breakdown Darwins work and made it easier to understand and how it works together to bring evolution.

THANK YOU

FOR LISTENING TO WHAT I HAVE LEARNT ABOUT DARWIN’S NATURAL SELECTION!