phenotype

Why does natural selection never act directly on genes? Number of times an allele occurs in a gene pool, compared to the total number of alleles in that pool for the same gene. What determines the number of phenotypes for a given trait?

Natural selection act on genotype or phenotype? NATURAL SELECTION acts on an organism’s characteristics (phenotype), not directly on its alleles (genotype). Natural selection favors a particular physical trait or behavioral characteristic over another.

A population is the smallest unit of living organisms that can undergo evolution. Within similar organisms are combinations of different genes and different gene types.

A logical analysis of the units and processes of biological evolution suggests that the natural fundamental unit of evolution is a FUE, that is, a genetic element with an independent evolutionary history. Evolution of a FUE on the macro scale is naturally represented by a tree.

Thus we have selection at three levels: genic, individual and intergroup all contributing to the maintenance of the t/T polymorphism. Would we expect to detect meiotic drive systems in natural populations?

Definition. Target selection refers to the process of selecting a single object from a field of multiple objects as the goal of a movement. It can also be used to refer to the deployment of covert attention to a selected object, even when an overt movement is not ultimately made.

The hierarchy of selection. We most typically think of natural selection working at the level of the individual, favoring those better at leaving behind more individual descendants. However, with a little imagination, we can see how natural selection might work at other levels of biological organization as well.

Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. Because individuals with certain variants of the trait tend to survive and reproduce more than individuals with other less successful variants, the population evolves.

In a case like this, the unit of selection, sometimes called the “target” of selection, is the single organism, the individual deer, and the property being selected, swiftness, also lies at the organismic level, in that it is exhibited by the intact and whole deer, and not by either parts of deer, such as cells, or …

Natural selection acts on the phenotype, the characteristics of the organism which actually interact with the environment, but the genetic (heritable) basis of any phenotype that gives that phenotype a reproductive advantage may become more common in a population. Natural selection is a cornerstone of modern biology.

Natural selection acts on populations. Individuals do not evolve in genetic evolutionary terms. Individuals may mutate, but natural selection acts by shifting the characteristics of the population as a whole.

The process of natural selection occurs in response to a number of conditions: Inherited Variation – There is genetic variation within a population which can be inherited. Competition – There is a struggle for survival (species tend to produce more offspring than the environment can support)

So, the correct answer is ‘Individuals with the most favorable traits survive and reproduce’

Alternative Title: analogous structure. Analogy, in biology, similarity of function and superficial resemblance of structures that have different origins. For example, the wings of a fly, a moth, and a bird are analogous because they developed independently as adaptations to a common function—flying.

The Selective Agent is the environmental factor acting on the population. The Selection Pressure is the effect of Natural Selection acting on the population. Selection Pressure -The organisms that are better suited to their environment survive the pressure of selective agents.

A selective pressure is any reason for organisms with certain phenotypes to have either a survival benefit or disadvantage. In the example above, strong sunlight is a selective pressure that favors darker-skinned people; lighter skin would be a disadvantage in these regions.

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