How does natural selection influence the evolution of living organisms?

Natural selection is a mechanism of evolution. Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success. This process causes species to change and diverge over time.

How can evolution happen randomly?

Evolution is not a random process. The genetic variation on which natural selection acts may occur randomly, but natural selection itself is not random at all. The survival and reproductive success of an individual is directly related to the ways its inherited traits function in the context of its local environment.

When does non random mating occur?

Nonrandom mating occurs when the probability that two individuals in a population will mate is not the same for all possible pairs of individuals. When the probability is the same, then individuals are just as likely to mate with distant relatives as with close relatives — this is random mating.

Which of the following describes the bottleneck effect?

Explanation: The bottleneck effect describes the phenomenon when a population has a sudden reduction in the gene pool due to natural environmental events, natural disasters, disease, or human involvement. This reduction in the gene pool will likely cause a bias that did not exist in the original population.

What is spontaneous mutation?

Spontaneous mutations are “the net result of all that can go wrong with DNA during the life cycle of an organism” (Glickman et al., 1986). Thus, the types and amounts of spontaneous mutations produced are the resultant of all the cellular processes that are mutagenic and those that are antimutagenic.

What is the relationship between mutation and evolution?

Population Genetics. When Darwin came up with his theories of evolution and natural selection, he knew that the processes he was describing depended on heritable variation in populations.

Can natural selection occur without evolution?

Natural selection can occur without leading to evolution if differences among individuals are not genetically based. Nonetheless, much of the phenotypic variation within a population is, in fact, genetically based; consequently, natural selection often does lead to evolutionary change.

What is the main idea of On the Origin of Species?

In 1859, he brought the idea of natural selection to the attention of the world in his best-selling book, On the Origin of Species. Natural selection is the process through which populations of living organisms adapt and change. Individuals in a population are naturally variable, meaning that they are all different in some ways.

Why do mutations happen randomly?

As the name implies, this process is also random, the result of accidental events, and without regard for the benefit of the organism. Most mutations get lost in the mix, especially when newly emerging, just because their host organisms fail to reproduce, or die from causes unrelated to genetics.

What is responsible for evolution over time?

The sum of all these factors is what is responsible for evolution, or change over time. Mutation, drift, selection, and environmental change all play a role. Three out of these four forces are random, without regard for the needs of the organism. Even selection can be random in its direction, depending on the environment.

Why are individuals in a population naturally variable?

Individuals in a population are naturally variable, meaning that they are all different in some ways. This variation means that some individuals have traits better suited to the environment than others. Individuals with adaptive traits—traits that give them some advantage—are more likely to survive and reproduce.