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Natural selection is the differential fitness of diverse phenotypes, causing some individuals to reproduce more than others according to their own relative fitness. Evolution is the change in gene frequencies of a population between generations. Therefore, natural selection can indeed occur without resulting in evolution, as changes in mean fitness do not necessarily lead to changes in gene frequencies.
For example, a deleterious allele may affect only homozygotes in a population. Thus, homozygotes may be selected against in equal proportions, causing them both to decrease in frequency at the same rate. While heterozygotes would have higher fitness, the mean change in frequencies would still equal zero. Both the dominant and recessive alleles are still present at the same frequency as before they were acted on by selection, due to the relative increase in heterozygotes.
Wiki User
∙ 12y ago
Wiki User
∙ 10y agoThe only other form of selection in Biology is artificial selection such as dog cross breeding and plant cross breeding by humans. Natural selection is indispensable to Darwinian evolution. Darwinian evolution is proven by evidence such as the geologic column deep within the ground composed of the fossils found in multiple layers of deposits that represent geologic epochs reaching millions of years into the past. The deeper layers in the column are older than those layers above them, and paleontologists find that the deeper down you go the less complex the life forms become. All the layers are arranged in the way paleontologists expect them to be according to Darwin's theory.
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How does natural selection provide a mechanism for evolution to occur?
by having sexual intercourse with hoes and getting money
Can natural selection occur without variation in a population?
no there is no genetic variation for natural selection to act upon
Does natural selection occur in the world today?
Yes, natural selection is always occurring.
Is Genetic diversity is the raw material for evolution?
Mutations occur randomly, and every once in a blue moon, a mutation offers some benefit to a individual of a particular species in a particular place and allows that individual to have more offspring than its peers. If the mutation provides enough benefit to some individuals, they will have a tendency to survive and reproduce (as per the principle of natural selection). Natural selection reduces variability by killing off less fit individuals. It is mutations that increase the variability and allow evolution (successful natural selection, not mass extinction, but controlled deaths) to occur. Without variability there is no evolution.
What does natural selection mean in science terms?
It is meant to indicate the Darwinian model for evolution, as opposed to for instance the Lamarckian model. It would be true that evolution occurs and has occurred even without Darwin; but until Darwin, various explanations would have been possible for why and how it happens. Darwin first formulated the thesis that evolution is directed by differential reproductive success.
What allows natural selection and evolution to occur?
the unequal ability of individuals to survive and reproduce
What allows natural selection and evolution to occur for a tree?
differences in the characteristics of individual trees
What are the 4 mechanisms by which evolution can occur?
genetic drift, mutation, natural selection, and migration
How is genetic diversity important to the concept of natural selection?
Without genetic diversity, natural selection cannot occur
How does natural selection provide a mechanism for evolution to occur?
by having sexual intercourse with hoes and getting money
What are three reasons for natural selection to occur?
1. different breeding 2. evolution 3.adaptation
Generally evolution by natural selection occurs quite slowly over?
Evolution through natural selection occurs slowly over millions of years. It has been hypothesized that evolution is the result of positive mutations that occur in a community of organisms that help them survive better. Evolution is essentially descent with modification.
Why is Lamark not called the father of Evolution?
Because it was Darwin who made it a scientifically plausible explanation, by providing a mechanism by which evolution could occur....Natural Selection.
Can natural selection occur without variation in a population?
no there is no genetic variation for natural selection to act upon
Natural selection cannot occur without what?
Variations within a population. Variations mean traits that only certain individuals have that give the individual a greater or lesser chance of reproducing.
What is the most important force in shaping evolution?
Evolution has two key driving forces without which it would not occur, but with which it must occur: The first is reproductive variation: this basically asserts that each organism is slightly different from both its parents and its siblings. The second is differential reproductive success: this asserts that features that allow their bearers to reproduce more successfully than members of the same species with different features are likely to be present in a greater part of the population in coming generations. In other words: the key driving forces behind evolution are variation and selection.
6 Explain why evolution by natural selection can not occur if the variation in a characteristic does not contribute to differences in fitness?
If there is not reproductive fitness conveyed by a variant trait, then natural selection has nothing to select and nothing to promote into the populational gene pool.
