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The term natural selection is most often defined to operate on heritable traits, because these directly participate in evolution. However, natural selection is "blind" in the sense that changes in phenotype can give a reproductive advantage regardless of whether or not the trait is heritable.
The Siberian Husky is a breed of medium-sized working sled dog.The breed belongs to the Spitz genetic family. It is recognizable by its thickly furred double coat, erect triangular ears, and distinctive markings, and is smaller than the similar-looking Alaskan Malamute.
Stabilizing selection (not to be confused with negative or purifying selection [1] [2]) is a type of natural selection in which the population mean stabilizes on a particular non-extreme trait value. This is thought to be the most common mechanism of action for natural selection because most traits do not appear to change drastically over time. [3]
The fitness is normally given by the symbol w=1-s where s is the selection coefficient. Natural selection acts on phenotypes, so population genetic models assume relatively simple relationships to predict the phenotype and hence fitness from the allele at one or a small number of loci. In this way, natural selection converts differences in the ...
Charles Darwin in 1868. Darwinism is a term used to describe a theory of biological evolution developed by the English naturalist Charles Darwin (1809–1882) and others. The theory states that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual's ability to compete, survive, and reproduce.
The most commonly used dog in dog sled racing, [16] the Alaskan husky is a mongrel [17] bred specifically for its performance as a sled dog. [18] The modern Alaskan husky reflects 100 years or more of crossbreeding with English Pointers, German Shepherd Dogs, Salukis and other breeds to improve its performance. [19]
A small region exists where the species meet in a cline—sustained by selection due to a flowering time divergence, thought to represent reinforcement taking place. [9] Similar patterns of both character displacement in sympatric populations of species have been documented in: [9] [3]: 361 Agrostis tenuis [60] Anthoxanthum odoratum [60] Gilia [61]
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]