What do you Mean by Evolution?
Evolution is the process by which species change over time through genetic variation and natural selection. It is characterized by genetic variations, heredity, and reproductive success over time. Some mechanisms that drive evolution are as follows:
- Natural Selection: Due to the selective pressures of the environment on organisms, there is a selection of individuals with traits that enhance their survival and reproduction. These traits are then passed on to offspring through heredity. For example, consider a population of moths with lighter and darker colours inhabiting an industrial area. Darker-colored moths will have a better survival advantage over lighter ones as they can camouflage against predators. This process, where individuals with favourable traits have higher reproductive success, leads to changes in the population over generations.
- Genetic variation: Due to genetic variation all individuals acquire different characters. This variation results from mutation and genetic recombination arising during sexual reproduction.
- Accumulation of changes: Over generations, natural selection and evolutionary processes can lead to significant changes in the characteristic features of a population which help in better survival of an organism. For example, these changes could be the emergence of a new trait, adaptation to a new environment, and the divergence of populations to develop newer species.
- Differential Reproductive Success: Individuals with advantageous or adaptive traits are more likely to survive and reproduce in the changing environment, passing genetic material to future generations. Over time, less advantageous or deleterious traits decrease.
Some other examples include the development of antibiotic resistance in bacteria, adaptation of finches on the Galápagos Islands (beak structure), etc.
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