What is the concept of natural selection focused on?

Natural selection is a fundamental concept in evolutionary biology that explains how certain traits become more common in a population over generations. It specifically focuses on heritable traits that promote survival and reproduction in a given environment. This process occurs because individuals with advantageous traits are more likely to survive and reproduce, passing those traits on to their offspring.

The emphasis on heritable traits is crucial because natural selection operates on genetic variations that can be inherited. Traits that enhance an organism's ability to survive in its environment—such as better camouflage, improved foraging skills, or resistance to disease—provide a selective advantage. Over time, these traits become more prevalent in the population, leading to evolutionary changes.

In contrast, traits that hinder survival or are acquired in response to environmental pressures do not play a direct role in the mechanism of natural selection. For instance, traits that an individual gains during its lifetime (like muscle strength from exercise) cannot be passed on genetically in the same way. Therefore, the focus of natural selection is solely on those heritable traits that contribute positively to an organism's fitness in its specific ecological niche.