What were the three major observations that charles darwin contributed to evolution?

The 3 major observations were:

1. More individuals are produced each generation that can survive.

2. Phenotypic variation exists among individuals and the variation is heritable (through parents' genes).

3. Those individuals with heritable traits better suited to the environment will survive.

Explanation:

Charles Darwin was a British naturalist who proposed the theory of known to everyone as  'The Theory of Evolution' through natural selection.

its temperature is increasing. this causes molecular vibrations to increase.