Random chance events that influence the survival and reproductive success of a population are known as
The correct answer and explanation is:
Correct Answer: Genetic drift
Explanation:
Genetic drift refers to random chance events that influence the survival and reproductive success of individuals in a population, particularly in small populations. Unlike natural selection, which is driven by traits that enhance survival or reproduction, genetic drift is a stochastic process that occurs without regard to an organism’s fitness. It involves the random fluctuation of allele frequencies from one generation to the next due to chance alone.
This randomness can lead to significant changes in a population’s genetic makeup over time. For instance, some individuals may not reproduce due to accidental causes such as natural disasters, disease, or random failure to mate, regardless of how well-adapted they are. When these random events remove certain alleles from the gene pool, genetic variation can decrease. Over many generations, this process can even lead to the fixation or complete loss of alleles.
One classic example of genetic drift is the bottleneck effect, which happens when a large population is drastically reduced in size due to a sudden event like a flood, fire, or disease. The few surviving individuals may not represent the genetic diversity of the original population. Another example is the founder effect, which occurs when a small group of individuals becomes isolated from a larger population and forms a new population. The new group’s gene pool is limited to the alleles present in the founding members, which may differ from the original population.
Genetic drift is especially important in conservation biology, as endangered species often have small populations where drift can greatly influence genetic diversity and long-term viability. Though it operates independently of natural selection, it can interact with selection to shape the evolutionary trajectory of populations. Over time, this random process can contribute to speciation and evolutionary change.