What are the three parts of natural selection?

Question

I have a biology final tomorrow and the teacher gave us a review packet. I can't find the the answer in any of my notes and we already turned in our books. Any help will be appreciated. Thanks!!

Answer 1

Chance mutation, adaptation, survival of the fittest.
Natural selection is the process by which favorable traits that are heritable become more common in successive generations of a population of reproducing organisms, and unfavorable traits that are heritable become less common. Natural selection acts on the phenotype, or the observable characteristics of an organism, such that individuals with favorable phenotypes are more likely to survive and reproduce than those with less favorable phenotypes. If these phenotypes have a genetic basis, then the genotype associated with the favorable phenotype will increase in frequency in the next generation. Over time, this process can result in adaptations that specialize organisms for particular ecological niches and may eventually result in the emergence of new species.

Natural selection is one of the cornerstones of modern biology. The term was introduced by Charles Darwin in his groundbreaking 1859 book The Origin of Species[1] in which natural selection was described by analogy to artificial selection, a process by which individuals with traits considered desirable by human breeders are systematically favored for reproduction. The concept of natural selection was originally developed in the absence of a valid theory of inheritance; at the time of Darwin's writing, nothing was known of modern genetics. Although Gregor Mendel, whose work is now considered the foundation of modern genetics, was a contemporary of Darwin's, this work would lie in obscurity until the early 20th century. The union of traditional Darwinian evolution with subsequent discoveries in classical and later molecular genetics is termed the modern evolutionary synthesis. Although other mechanisms of molecular evolution, such as the neutral theory advanced by Motoo Kimura, have been identified as important causes of genetic diversity, natural selection remains the single primary explanation for adaptive evolution
The term "natural selection" has slightly different definitions in different contexts. In simple terms, "natural selection" is most often defined to operate on heritable traits, but can sometimes refer to the differential reproductive success of phenotypes regardless of whether those phenotypes are heritable. Natural selection is "blind" in the sense that individuals' level of reproductive success is a function of the phenotype and not of whether or to what extent that phenotype is heritable; following Darwin's primary usage[1] the term is often used to refer to both the consequence of blind selection and to its mechanisms.[3][4] It is sometimes helpful to explicitly distinguish between selection's mechanisms and its effects; when this distinction is important, scientists define "natural selection" specifically as "those mechanisms that contribute to the selection of individuals that reproduce," without regard to whether the basis of the selection is heritable. This is sometimes referred to as 'phenotypic natural selection.'[5]

Traits that cause greater reproductive success of an organism are said to be "selected for" whereas those that reduce success are "selected against". "Selection for" a trait may also result in the "selection of" other correlated traits that do not themselves directly infuence fitness. This may occur as a result of pleiotropy or gene linkage.

Answer 2

organic determination or differential determination, by utilising the community interactions or the habitat, produces modifications interior the relative frequencies of alleles interior the inhabitants’s phenotypic gene pool which would be graphed as directional, stabilizing, and disruptive. Disruptive determination favors the characteristics on the bounds of the bell curve. Bimodal determination is energetic determination for the severe variations of the phenotype mixed with detrimental determination for the regular phenotype. Stabilizing determination has a tendency to decide on for the intermediate or regular fee of the trait phenotype and against the severe variations of the phenotype. extensively version variations of the alleles are decreased in frequency interior the inhabitants so the gene pool exchange into greater homogeneous for the genes coding for the trait. severe genetic version for the stabilized trait is decreased on the same time as the regular fee allelic sort is stored. Directional determination - the phenotype at basically one end of the inhabitants's bell curve fits the area of interest. This has a tendency to shift the regular fee of the bell curve for the phenotype as detrimental determination removes the phenotype from the different severe end of the bell curve.

Answer 3

Natural selection is a three part process. First,there must exist differences among individ-uals in some trait. Second, the trait differencesmust lead to differences in survival and reproduc-tion. Third, the trait differences must have a ge-netic basis. Natural selection results in long-termchanges in the characteristics of the population