Natural selection acts on the phenotype and not on the genotype. Explain the meaning of this statement?
101735
Natural selection is a mechanism of evolution which involves the "interaction" with environment. The fitness of an organism to their environment depends on it's phenotype, not genotype, since genotype doesn't "interact" with environment.\n\nAs for example, black heterozygote moth which lives in a polluted area (black sky), have the same fitness as black homozygote moth at the same condition.They're harder to be noticed by their predator, hence have a better chance to survive compared to those white moths. \nBoth of the moths have different genotype, but since the two genotypes are translated into one same phenotypes, it doesn't affect their fitness.\n\nAnd as conclusion, natural selection only works on phenotypes, since only phenotypes that have direct "interaction" to the environment.
978981
In biology, evolution is the change in the heritable traits of a population over successive generations, as determined by shifts in the allele frequencies of genes. Over time, this process can result in speciation, the development of new species from existing ones.
182301
Alleles. Mutations are just general changes in the DNA, they do not necessarily have to be in a gene, therefore, not all mutations cause the creation of new alleles (ie if a mutation occurred in an area that did not code for anything)
18875
Both are required. Variation in the population provides something for natural selection to act on. Mutation is one way to generate variation. Recombination  during meiosis is another. This sounds like a trick question. The correct answer is not one or the other--you would have to explain variation. One part of the process generates choices, the other part of the process "chooses" among the available options.
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Mutation generates differences.  Most mutations are deleterious and natural selection tends to eliminate them quickly.  Many are neutral and are retained to some degree because there's nothing weeding them out.  A few are positive and variation is also lost in that case because selection will eliminate the other variations.\n\nThere is a process called frequency dependent selection whereby a trait is advantageous but only if its rare.  For example since hosts adapt to a certain kind of parasite, it is advantageous for a parasite to have rare characteristics.  That way the host is unlikely to have seen that model before and the parasite is likely to be successful.  In that case selection actually favors a lot of versions in a species because as soon as anything become really numerous it becomes deleterious.
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lol, that's natural selection at work. \ngenetic variance produces all sorts of things, but those who won't reproduce won't pass on those genes.\nits as simple as that. they're not any less of a person, they just won't have offspring who are genetically similar.
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Natural selection acts on all living organisms.  Every time a lion catches one zebra and another gets away, that's natural selection.  Every time a certain plant's seeds grow while another's don't, that's natural selection.  If the girl you like marries someone else, that's natural selection.  \n\nNatural selection is all about biological fitness (having positive traits).  The strong survive and reproduce.  The weak don't.  It's that simple.
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Here's a little known fact - the theory of natural selection - very few on YA can describe it correctly yet it's very simple:\nThere are just 3 assumptions:\n\n1. Individual members of a species are not always exactly alike. A population of similar organisms displays variability.\n\n2. Organisms possess some mechanism by which offspring tend to be like their parents. That is, individual traits are heritable.\n\n3. Totally unrestricted breeding doesn't happen. No population can reproduce forever without limit. So clearly there must be some force at work to reduce populations.\n\nFrom these assumptions Darwin concluded the theory of natural selection - some of the variations between individuals are inherited by their offspring, and, in a world where not everyone can survive, some of these inherited characteristics give some individuals a better chance of survival.
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Genetic information is increased by mutation of the genetic material inside an organism. Natural selection simply removes the less advantageous mutations. An increase is not necessarily an improvement but is simply an increase.\n\nDo not think of one current species becoming another, instead think about one common ancestor to both and then how the mutations occurred over million of years and generations to present very different animals.\n\nCertainly, there is a consciousness that can be applied to the selection. Genocide is a good example of somebody thinking they can direct the development of a whole species. Surely the Final Solution is evidence that humans can think in this way. It doesn't mean we should but it proves that we can.
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You knowledge of English appears to be even worse than your knowledge of science, which is depressing.\n\nLook, 'fitness' in evolutionary theory refers to fitness to reproduce. Those who are fit are those who can produce offspring, NOT those who evolve.\n\nSo of course all multicellular organisms eventually die. That is the whole point. Their offspring then inherit their niche. And because fitness is defined by the number of offspring produced the fittest organisms inherit the larger share.\n\nI hope this clears up a small part of your ignorance.
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D\n\nPoint C is a frequent misunderstanding of the principle of evolution. Animals do not evolve on purpose or to any particular goal. There was a long squabble about this early in the 20th century: see if you can find out anything about the Soviet biologist Lysenko. \n\nPoint A is due to Malthus. \n\nI don't recognise point B.
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Genes are not really dominant or recessive, alleles of genes are dominant or recessive.  Alleles are the different forms a gene can take - ie, different alleles have slightly different sequences.  Dominant or recessive just refers to which allele codes for the protein that is actually going to have an impact on the phenotype (how an organism looks).
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Darwin's theory never said anything about 'survival of the fittest'.  That was a paraphrasing used in some reviews to explain the theory of natural selection, and is quite innaccurate.\n\nFitness in terms of natural selection ONLY means the ability to pass on an organism's genetic heritage to the next generation.  It DOES NOT connote superiority over any other organism.  By definition any organism that successfully reproduces is 'fit'.\n\nMis-applying this idea of 'Survival of the Fittest' to claim that anyone who survives must be superior has been the cause of some of the greatest evils of the 20th century.  The practice of Eugenics, extreme capitalism, Soviet communism and Nazi party doctrine all misquoted and misunderstood evolutionary theory to justify their actions.
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it depends on how long youre talking about. natural selection will 'select' the more fit individuals that are better suited to their environment. therefore if competition exists between individuals those better adapted to the environment will win, thus natural selection picks it.
544104
I would agree with you that humans causing extinction can sometimes be defined as natural selection. However, our nervous systems have allowed us to have a different impact on the world around us. We are able to make decisions to avoid the extinction of other animals and have the capacity to take action a lot of the time. \n\nHope this helps.\n\nand as a side note "survival of the fittest" was retracted by Darwin when he saw that his cousin Galton was using it promote societal improvement. This is not what Darwin meant. Think of natural selection as selecting against  traits, characteristics, or behaviors that are harmful to the organism's ability to survive long enough to reproduce. Survival of the fittest just sounds like constant improvement.
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Genetics and evolution.
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phenotype... ;p\n\nthe phenotype of an individual organism is either its total physical appearance and constitution or a specific manifestation of a trait, such as size, eye color, or behavior that varies between individuals. phenotype is determined to some extent by genotype, or by the identity of the alleles that an individual carries at one or more positions on the chromosomes. many phenotypes are determined by multiple genes and influenced by environmental factors.