Search results
Results From The WOW.Com Content Network
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, ...
Natural selection is inherently involved in the process of speciation, whereby, "under ecological speciation, populations in different environments, or populations exploiting different resources, experience contrasting natural selection pressures on the traits that directly or indirectly bring about the evolution of reproductive isolation". [54]
The outcome of evolution is not a perfectly designed organism. The end products of natural selection are organisms that are adapted to their present environments. Natural selection does not involve progress towards an ultimate goal. Evolution does not strive for more advanced, more intelligent, or more sophisticated life forms. [25]
Macroevolution is guided by sorting of interspecific variation ("species selection" [2]), as opposed to sorting of intraspecific variation in microevolution. [3] Species selection may occur as (a) effect-macroevolution, where organism-level traits (aggregate traits) affect speciation and extinction rates, and (b) strict-sense species selection, where species-level traits (e.g. geographical ...
Life history theory draws on an evolutionary foundation, and studies the effects of natural selection on organisms, both throughout their lifetime and across generations. [8] It also uses measures of evolutionary fitness to determine if organisms are able to maximize or optimize this fitness, [ 9 ] by allocating resources to a range of ...
If natural selection acts strongly on the two populations, they may become reproductively isolated, unable to reproduce viable, fertile offspring. [1]: 202–210 For allochronic speciation to be considered to have actually occurred, the model necessitates three major requirements: [2]
Natural selection can act on specific alleles both directly or indirectly. [ 29 ] [ 22 ] [ 34 ] In direct selection, the frequency of the selected allele is favored to the extreme. In cases where an allele is indirectly selected, its frequency increases due to a different linked allele experiencing selection ( linkage disequilibrium ).
Essentially, natural selection is a mechanism that contributes to directional gene selection in individuals that reproduce. Traits that cause greater reproductive success of an organism are favored, whereas those that reduce reproductive success are selected against. [17] [18] In contrast to learning, natural selection is solely a biological ...