Here's why:
* Evolution is about change in allele frequencies: Evolution is defined as a change in the genetic makeup of a population over generations. Alleles are different versions of a gene, and their frequencies within a population determine the traits that are expressed.
* Changes happen through various mechanisms: These changes in allele frequencies can be driven by various evolutionary mechanisms, including:
* Natural selection: Individuals with advantageous traits are more likely to survive and reproduce, passing on their alleles to the next generation.
* Genetic drift: Random fluctuations in allele frequencies can occur, especially in small populations.
* Gene flow: The movement of individuals (and their alleles) between populations can alter allele frequencies.
* Mutation: New alleles can arise through mutations, introducing new genetic variation into the population.
Important Note: Evolution does not necessarily mean that a population is becoming "better" or more complex. It simply means that the genetic makeup of the population is changing.
