Natural Selection

Natural Selection is one of the key ingredients of constant evolution, followed by mutation, migration, and genetic drift.

Both Charles Darwin and Jean-Baptiste Lamarck proposed different explanations of what natural selection was and how it occurred.

Jean-Baptiste Lamarck's Theory

1. The Giraffe stretches their necks to reach the leaves
2. Eventually the necks of the giraffes grow with use
3. The Giraffes offspring inherit the long neck

Charles Darwin's Theory

1. Giraffes with longer necks can reach more leaves
2. Making them more likely to gain enough nutrition to survive and go onto reproduce
3. The Giraffes offspring inherit the long neck trait

After data gathering and analysis Lamarck was dismissed, Darwin's theory was concluded true.

Further break down of Darwin's theory;

Observation 1- All members of any population often vary in their inherited traits.

Observation 2- Every species is capable of producing more offspring than the environment can naturally support, therefore meaning that some will fail to survive and reproduce.

Inference 1- Organisms with inherited traits are more likely to survive and go onto reproduce, leaving more offspring in the environment compared to others of their species.

Inference 2- The unbalanced ability of specific organisms to survive and reproduce eventually leads to an accumulation of desirable traits in the population occurring over generations.

Key Points

• Wide range in variation
• Variation is caused by the significant number of differences in genes
• The characteristics which are most suited to the environment are more likely to survive and be passed on
• Genes are passed to the offspring