What is natural selection and how does it drive evolution?

Natural selection is the process where organisms better adapted to their environment tend to survive and produce more offspring.

In more detail, natural selection is a key mechanism of evolution, the process that drives the diversity and complexity of life on Earth. It was first proposed by Charles Darwin in his book 'On the Origin of Species' in 1859. Natural selection operates on the principle of 'survival of the fittest', where 'fittest' refers to the organisms that are best adapted to their specific environment.

Organisms in a species show variation in their characteristics due to differences in their genes. These variations can affect an organism's ability to survive and reproduce. For example, a bird with a beak shape that is better suited to accessing food in its environment is more likely to survive and reproduce than a bird with a less suitable beak shape. The bird with the advantageous beak shape will then pass on its genes, including those for the beneficial beak shape, to its offspring. Over time, this can lead to the advantageous trait becoming more common in the population, a process known as evolution.

Natural selection can lead to speciation, where one species splits into two or more separate species. This can occur when populations of the same species become geographically isolated from each other. In their separate environments, different traits may become advantageous, leading to different evolutionary paths for the separate populations.

In summary, natural selection is a fundamental process in biology that drives evolution. It explains how species adapt to their environment and how new species can arise. Understanding natural selection is crucial for understanding the complexity and diversity of life on Earth.