GENE POOL:
A gene pool is a variation for all possible genes available. These variations are called Alleles. When a gene pool is changed the population of a species changes, either for better or not. Gene pool is considered a micro-evolution since the changes that occur by the mechanisms are small changes within one species. There are 5 mechanisms, Natural Selection, Mutation, Genetic Drift, Gene Flow and Non-Random Mating.
Natural Selection: This mechanism changes the population of a species to the best it can. Natural selection creates a population that is the best adaptable and best fit for survival. These genes who are "best fit" are passed down to future generations and therefore the next generation acquires the best of the genes from its past generations.
Example: Galapagos Islands finches select their reproduction mates to adapt to their environment. That's way their beaks vary in sizes and shapes determining on their source of food and environment.
Mutation: Mutation is random change in the DNA of an organism. This changes can be passed on to future generations and can either be good, bad or neutral. These changes occur in the DNA strand where for example an Thymine can be switched to a Gyanine. These effects are highly variable and usually harmful but rarely produce favourable traits.
Example: A gene code could be deleted or added or switched. The Spirit Bear, is white by a mutation that occurred in their DNA code. This change is an advantage when the bears are trying to catch their food(salmon) and being hunted.
Genetic Drift: When there is a change in the gene pool as a result of random chance events. This can cause a species or allele to become more popular than the other. This can cause a disappearance in an entire allele in a population due to the low reproduction rate after low desirable rate of this allele.
Example: Only two green butterflies left, one male and one female, the female dies unexpectedly and now there isn't another way to reproduce and pass on their generations since there won't be future generations from their species.
Genetic Flow: The transfer of genes from one population to another. This can introduce new variations into a population. It can also separate populations that were joined into two independent populations.
Example: When a species migrates to a different location and mates with a new species, creating a new species and is able to pass down its genes to future generations.
Non-Random Mating: Organisms rarely mate randomly. They always pick the best and most desirable traits and best adaptable. Non-Random Mating usually occurs within the same species and population.
Example: Harems: one male has many females
Assortative Mating: choosing those like you
Sexual Selection: based on selection criteria(colour, displays, territory, song, size)
A gene pool is a variation for all possible genes available. These variations are called Alleles. When a gene pool is changed the population of a species changes, either for better or not. Gene pool is considered a micro-evolution since the changes that occur by the mechanisms are small changes within one species. There are 5 mechanisms, Natural Selection, Mutation, Genetic Drift, Gene Flow and Non-Random Mating.
Natural Selection: This mechanism changes the population of a species to the best it can. Natural selection creates a population that is the best adaptable and best fit for survival. These genes who are "best fit" are passed down to future generations and therefore the next generation acquires the best of the genes from its past generations.
Example: Galapagos Islands finches select their reproduction mates to adapt to their environment. That's way their beaks vary in sizes and shapes determining on their source of food and environment.
Mutation: Mutation is random change in the DNA of an organism. This changes can be passed on to future generations and can either be good, bad or neutral. These changes occur in the DNA strand where for example an Thymine can be switched to a Gyanine. These effects are highly variable and usually harmful but rarely produce favourable traits.
Example: A gene code could be deleted or added or switched. The Spirit Bear, is white by a mutation that occurred in their DNA code. This change is an advantage when the bears are trying to catch their food(salmon) and being hunted.
Genetic Drift: When there is a change in the gene pool as a result of random chance events. This can cause a species or allele to become more popular than the other. This can cause a disappearance in an entire allele in a population due to the low reproduction rate after low desirable rate of this allele.
Example: Only two green butterflies left, one male and one female, the female dies unexpectedly and now there isn't another way to reproduce and pass on their generations since there won't be future generations from their species.
Genetic Flow: The transfer of genes from one population to another. This can introduce new variations into a population. It can also separate populations that were joined into two independent populations.
Example: When a species migrates to a different location and mates with a new species, creating a new species and is able to pass down its genes to future generations.
Non-Random Mating: Organisms rarely mate randomly. They always pick the best and most desirable traits and best adaptable. Non-Random Mating usually occurs within the same species and population.
Example: Harems: one male has many females
Assortative Mating: choosing those like you
Sexual Selection: based on selection criteria(colour, displays, territory, song, size)