How do survival and reproductive success drive natural selection?

Survival and reproductive success drive natural selection by determining which traits are passed on to future generations.

Natural selection is a fundamental concept in biology, often described as 'survival of the fittest'. This phrase doesn't mean the strongest or the fastest, but rather those best adapted to their environment. Survival and reproductive success are the two key factors that determine this fitness.

Survival is the first step. Individuals within a species exhibit a range of variations in their traits, some of which may give certain individuals an advantage in their specific environment. These advantages could be anything from better camouflage, resistance to disease, or more efficient food gathering. Individuals with these advantageous traits are more likely to survive longer than those without, and therefore have more opportunities to reproduce.

Reproductive success is the second step. Not only do individuals need to survive, but they also need to reproduce to pass on their genes to the next generation. Those individuals with traits that increase their chances of finding a mate and successfully breeding will have more offspring. These offspring will inherit the advantageous traits, increasing their frequency in the population over time.

This process of natural selection can lead to significant changes in species over many generations. Traits that enhance survival and reproductive success become more common, while those that do not decrease. This can eventually lead to the development of new species, a process known as speciation.

In summary, survival and reproductive success are the driving forces behind natural selection. They determine which individuals pass on their genes, shaping the traits of species over time. This process is fundamental to the diversity and complexity of life on Earth.