Natural selection acts solely on phenotype. However, the probability of certain genotypes can be affected by the probability of a certain phenotype surviving. For example, say all the hawks eat all the dark mice and the dark allele for skin color is dominant (D). The hawk doesn't care whether the dark mice is Dd or DD, they will eat them either way and in the same proportions. This affects the genotypes of the populations because in this case, genotypes of DD and Dd will become less frequent than dd.
Natural selection acting on phenotypes can be best described in an illustration:
Imagine there were zebras born with short legs and zebras born with long legs. They inhabit an entire savanna in Africa. Those with longer legs are able to run faster and those with shorter legs run slower. For instance, a lion gets introduced into the environment, being the predator in this case. You would expect that the zebras with longer legs would have a higher survival rate since they can outrun the lion. The zebras with short legs get left behind to be the lion's dinner. Because of this, the long-legged zebras are able to survive, reproduce, and pass on their genes to the next generation. The allele frequency for short legs decrease and the frequency for long legs increase. Survival of the fittest is key to natural selection.
The environment is constantly changing so no species is perfectly adaptable to their environment. Since it is always changing, the advantageous traits are also changing depending on the environment. Organisms who have the highest survival rates are the ones who possess the most adaptable traits and have the ability to pass on genes.
The dominant genotype will be the one that actually shows, so just carrying the recessive gene isn't enough to display symptoms of it. Because of this, natural selection does not have to act on things carrying the genotype, they need to act on the ones that are actually displaying this characteristic.
Technically both. Genotypes are altered by mutations which are expressed in the organism's phenotype. These mutations, and their expression, are what make an organism more or less "fit".
both. Mainly, natural selection act on genotype. Phenotype is given by genotype, by 95% lets say.
Natural selection acts on phenotype variation.
Yes, it does.
It acts on the phenotypes.
Genotypes.
This seems to be an odd question to ask... Unless I'm mistaken, the phenotype of a given organism is governed by its genotype, and changed a fair amount by the organism's environment. Consider the following circumstances: Organism A has a long set of arms, and has a "long arm" allele. Organism B has short arms and a "short arm" allele. For example, A's genotype has the "long arm" allele, and seen in its phenotype it has long arms. The converse is true for B. Judging by your usage of technical terms in your question, I'm sure I don't need to tell you that A will out-compete B, assuming they are in a food-is-up-high environment. So, A will end up with more offspring than B, again assuming that A and B are members of different species. Eventually organism A will become prevalent, and natural selection will have caused there to be more organisms with the "long arms" phenotype, and the "long arm" allele in their genotype. In summation, Genotype governs Phenotype, and the best geno- and phenotypes will be chosen by natural selection. By an organism having a superior phenotype, it also has a superior genotype.
Crossing-over increases the genetic variation within a population, which is required for natural selection to act upon.
A phenotype is simply an observable trait. A genotype is the genetic state that underlies the physically expressed characteristics. Therefore, in order to determine a person's phenotype for eye color one must only look and note the color of the subjects' eyes.
The structure of DNA is stable but it can undergo mutation once in a while to provide the raw materials for natural selection to act upon. lol from Kaplan huh?
How they look and act...eye colorhair/color styleageheightskin tonestyle of dressspecial skills/abilities*If this is a biology question, the answer is phenotype
in need helpl asap
yes
False
This seems to be an odd question to ask... Unless I'm mistaken, the phenotype of a given organism is governed by its genotype, and changed a fair amount by the organism's environment. Consider the following circumstances: Organism A has a long set of arms, and has a "long arm" allele. Organism B has short arms and a "short arm" allele. For example, A's genotype has the "long arm" allele, and seen in its phenotype it has long arms. The converse is true for B. Judging by your usage of technical terms in your question, I'm sure I don't need to tell you that A will out-compete B, assuming they are in a food-is-up-high environment. So, A will end up with more offspring than B, again assuming that A and B are members of different species. Eventually organism A will become prevalent, and natural selection will have caused there to be more organisms with the "long arms" phenotype, and the "long arm" allele in their genotype. In summation, Genotype governs Phenotype, and the best geno- and phenotypes will be chosen by natural selection. By an organism having a superior phenotype, it also has a superior genotype.
Yes it does. Without variance in the organisms genome, that gives variance to the phenotype, there would be nothing for natural selection to select from.
The phenotype or genome of the individual organism. Remember, individuals are selected, populations evolve.
This seems to be an odd question to ask... Unless I'm mistaken, the phenotype of a given organism is governed by its genotype, and changed a fair amount by the organism's environment. Consider the following circumstances: Organism A has a long set of arms, and has a "long arm" allele. Organism B has short arms and a "short arm" allele. For example, A's genotype has the "long arm" allele, and seen in its phenotype it has long arms. The converse is true for B. Judging by your usage of technical terms in your question, I'm sure I don't need to tell you that A will out-compete B, assuming they are in a food-is-up-high environment. So, A will end up with more offspring than B, again assuming that A and B are members of different species. Eventually organism A will become prevalent, and natural selection will have caused there to be more organisms with the "long arms" phenotype, and the "long arm" allele in their genotype. In summation, Genotype governs Phenotype, and the best geno- and phenotypes will be chosen by natural selection. By an organism having a superior phenotype, it also has a superior genotype.
Although organisms with the same physical characteristics have the same PHENOTYPE, they might have different GENOTYPE, or genetic makeup.
The natural selection process is a gradual one and is found to pose a gradual effect on the genes because the nitrogenous base bonds in the genes are not an easy task to alter and the hydrogen bonds existing between these bases would change according to change in the environmental barriers that arise out of catastrophes to which the selection has to incur. So the gradual modification is found to be observed in the level of genes in case of natural selection in animals. This was the case for Galapogous island finches in case of Darwinian studies in natural selection. The genotype variations are the gradual ones leading to changes in the phenotype of the organisms.
I know of no government that acts, in any direct or significant way, on natural selection.
Yes, that would be called the Homologous structure, and that changes in natural selection.
Natural Selection is driven by random mutations and sexual reproduction. Organisms produce more offspring than can survive. These offspring compete for resources for food and water and who can aviod stuff such as predators and disease. Sexual Reproduction allows a population to have variation. If all of a population was the same, then it could easily die out if it had a adaptation that decreased its chance of survival. With sexual reproduction, all of a population has some sort of variation. Random Mutations allow organisms to gain new adaptions to help them survive in their environment. Together, Random mutations and sexual reproduction allow organisms that can survive in their environment survive and pass on their genes to their offspring.