Natural Selection

Innate behavior is known as inflexible behavior, in which learning plays no role in the behavior. Communicating, courtship, and decision making all rely on learned behavior from the environment.

Innate behavior is known as inflexible behavior, in which learning plays no role in the behavior. Communicating, courtship, and decision making all rely on learned behavior from the environment.

Heterozygote advantage occurs when heterozygotes at a particular locus, such as pigmentation, have greater fitness than do both kinds of homozygotes. If the heterozygote favors an intermediate phenotype, such as beige mice, it is also stabilizing selection. Frequency-dependent selection occurs when the fitness of a phenotype depends on how common it is in the population. Together, heterozygote advantage and frequency-dependent selection lead to a balancing system. The founder effect occurs when a few individuals of a population become isolated and form a new population whose gene pool differs from the original population. Directional selection occurs when conditions favor individuals at one extreme of a phenotypic range, thereby shifting a population’s frequency curve for the phenotypic character in one direction or another.

Charles Darwin studied finches in the Galapagos, which prompted his work on natural selection. This was observed as only the finches who were evolutionarily prepared reproduced, thus increasing their traits in the gene pool

Heterozygote advantage occurs when heterozygotes at a particular locus, such as pigmentation, have greater fitness than do both kinds of homozygotes. If the heterozygote favors an intermediate phenotype, such as beige mice, it is also stabilizing selection. Frequency-dependent selection occurs when the fitness of a phenotype depends on how common it is in the population. Together, heterozygote advantage and frequency-dependent selection lead to a balancing system. The founder effect occurs when a few individuals of a population become isolated and form a new population whose gene pool differs from the original population. Directional selection occurs when conditions favor individuals at one extreme of a phenotypic range, thereby shifting a population’s frequency curve for the phenotypic character in one direction or another.

Charles Darwin studied finches in the Galapagos, which prompted his work on natural selection. This was observed as only the finches who were evolutionarily prepared reproduced, thus increasing their traits in the gene pool

Darwin described his theory as "descent with modification," meaning that offspring inherit their genetic material from their parents, but with slight modifications. Darwin proposed that those slight modifications which provided a fitness benefit (made it more likely that an organism would reproduce) were more likely to be passed on.

Frequency-dependent selection is a type of natural selection in which the fitness of a phenotype depends on frequency. This includes positive frequency-dependent selection—fitness of a phenotype increases when it is common—and negative frequency-dependent selection—fitness of a phenotype decreases when it is common.

Natural selection is defined as survival and reproduction based on a specific phenotype. Phenotypes that increase reproductive fitness are “selected for” on different levels. Natural selection can take place on different levels of biological organization including gene, individual, and group levels.

Darwin described his theory as "descent with modification," meaning that offspring inherit their genetic material from their parents, but with slight modifications. Darwin proposed that those slight modifications which provided a fitness benefit (made it more likely that an organism would reproduce) were more likely to be passed on.