Final answer:
The theory of evolution by natural selection explains how species adapt and evolve over time based on inherited traits, competition for resources, and differential reproductive success, leading to changes in species characteristics.
Step-by-step explanation:
The Theory of Natural Selection
The theory of evolution by natural selection is a cornerstone of modern biology that explains how species adapt and change over time. It was independently developed by Charles Darwin and Alfred Russel Wallace. The theory posits that there are variations in traits within a population, and these traits are inherited. Due to the production of more offspring than the available resources can support, there is a natural competition for survival. As a result, those individuals with traits that confer a survival and reproductive advantage are more likely to reproduce and pass those advantageous traits on to the next generation. Over time, this process can lead to significant changes in the characteristics of a population, including the emergence of new species, in a phenomenon known as descent with modification.
Natural selection is driven by three main principles: inherited variation in traits, competition for scarce resources, and differential survival and reproduction among individuals in a population. It is the primary mechanism by which evolution shapes organisms to be better suited to their environment. The theory of evolution by natural selection is widely accepted in the scientific community, as no evidence has been found to disprove it.