it's better to explain it using an example. say there are two types of moths - black and white. the black allele and the white allele together make up the gene pool (all of the alleles together) for the moth species. then say that there are only black trees in the habitat of these moths. in the eyes of a predator, it is much easier to see the white moths on the black trees than the black ones, so they continually get eaten. therefore, the allele frequency of the white moths goes down. because the moths are being eaten and there are less and less of them, we say they are being selected against and eventually the white moths die off, because they are not adapted to their environment
Well, let's give an example. Suppose you use pesticides on an insect population. At first, it seems to be working and most of the insects died. Those who survived somehow carried the genes that has pesticide resistance. These insects with the genes for pesticide resistance quickly reproduced and passed on their genes. Over time, natural selection occured, and the pesticide resistance became less effective. Note that environmental change doesn't create new alleles that are benefitial in the environment, but rather, natural selection select alleles from a population's gene pool that will be benefitial. Thus, natural selection acts on a population and its gene pool rather than the individual.
The reason it works on populations is because evolution is a change in the allele frequency over time. That only happens in populations, not individuals.
Individuals die. So any germ line mutations/variations need to be passed on to progeny for the change in allele frequency in populations of organisms that defines evolution.
Evolution of populations happens as new individuals are born and old individuals die. Thus populations evolve and individuals do not.
Populations evolve, but individuals are selected. Natural selection affects individual organisms.
Be careful with this, it is usually misinterpreted as survival of fittest individuals. Instead it is survival of fittest population via death of some individuals early. Individuals never evolve, they are fixed genetic snapshots in the movie of life, they simply live or die. Populations evolve.
migration
This statement refers to the fact that evolution occurs at the level of populations over generations, with changes in allele frequencies leading to evolution. It emphasizes that individual organisms do not evolve within their lifetimes, as they do not change genetically, but rather it is the population as a whole that evolves.
Yes, populations evolve. Individuals/genes are selected.
Evolution in Mendelian Populations was created in 1931.
Evolution is the change in allele frequency over time in a population of organisms.Short answer, populations are the only thing that evolves. Individuals die. Traits are passed on to progeny that make up the variations in the populations that evolve.
The modern definition of evolution works at the level of genes, phenotypes and populations whereas Darwinism was mainly concerned with organisms, speciation and individuals. According to the modern definition of evolution, the populations evolve by changes in gene frequency brought about by random genetic drift, gene flow and natural selection. This change is gradual.
Mutations in an individuals germ line can be passed into progeny and if these mutations are beneficial then the allele frequency in the individuals population can change which is evolution. Over time and with many beneficial mutations against a favorable environment a population, or populations, most often geographically isolated, can change alleles so much that the two split populations can no longer interbreed and you have a new species; macro-evolution.
The implications of transgenesis is that we are introducing new genes into our world and they will impact ecosystems, genetic biodiversity, health of individuals, survival and evolution of populations.
It acts on populations.
Maurizio Salaris has written: 'Evolution of stars and stellar populations' -- subject(s): Evolution, Galaxies, Populations, Stars
Populations evolve, but individuals are selected. Natural selection affects individual organisms.
If you're referring to "sexual reproduction" and the theory of evolution, then yes. It plays a major part in the evolution of organisms which use it, as it offers major advantages.