Watching this resources will notify you when proposed changes or new versions are created so you can keep track of improvements that have been made.
Favoriting this resource allows you to save it in the “My Resources” tab of your account. There, you can easily access this resource later when you’re ready to customize it or assign it to your students.
Genetic variation is a measure of the genetic differences that exist within a population.
The genetic variation of an entire species is often called genetic diversity.
Genetic variations are the differences in DNA segments or genes between individuals and each variation of a gene is called an allele.For example, a population with many different alleles at a single chromosome locus has a high amount of genetic variation.
Genetic variation is essential for natural selection because natural selection can only increase or decrease frequency of alleles that already exist in the population.
Variation allows some individuals within a population to adapt to the changing environment.
Because natural selection acts directly only on phenotypes, more genetic variation within a population usually enables more phenotypic variation.
Some new alleles increase an organism's ability to survive and reproduce, which then ensures the survival of the allele in the population.
Other new alleles may be immediately detrimental (such as a malformed oxygen-carrying protein) and organisms carrying these new mutations will die out.
Neutral alleles are neither selected for nor against and usually remain in the population.
Genetic variation is advantageous because it enables some individuals and, therefore, a population, to survive despite a changing environment.
Some species display geographic variation as well as variation within a population.
Geographic variation, or the distinctions in the genetic makeup of different populations, often occurs when populations are geographically separated by environmental barriers or when they are under selection pressures from a different environment.
One example of geographic variation are clines: graded changes in a character down a geographic axis.
Gene duplication, mutation, or other processes can produce new genes and alleles and increase genetic variation.
New genetic variation can be created within generations in a population, so a population with rapid reproduction rates will probably have high genetic variation.
However, existing genes can be arranged in new ways from chromosomal crossing over and recombination in sexual reproduction.
Overall, the main sources of genetic variation are the formation of new alleles, the altering of gene number or position, rapid reproduction, and sexual reproduction.
Assign this as a reading to your class
Assign just this concept, or entire chapters to your class for free. You will be able to see and track your students' reading progress.
Individuals better suited to the new climate will help less-suited individual survive the change, The individuals would produce more offspring, Individuals will only create offspring well-suited to the climate change, and Some individuals will possess traits better suited to the new climate and be more likely to pass them on