1. All life on Earth shares a common ancestor. This means that all living things, from bacteria to humans, are connected through a long history of descent with modification. Over vast periods of time, changes accumulated in populations, eventually leading to the diversity of life we see today.
2. Evolution occurs through natural selection. This means that individuals within a population vary in their traits, and some of these traits are more advantageous for survival and reproduction in a particular environment. Individuals with these advantageous traits are more likely to survive and pass on their genes, leading to a gradual change in the population over time.
These two claims are interconnected. The shared ancestry of life provides the foundation for natural selection to act upon. Natural selection, in turn, drives the diversification and adaptation of life over generations.
