Natural Selection

By promoting outbreeding depression due to incompatible gene combinations from different environments

Through continuous backcrossing, it maintains high levels of fitness by eliminating deleterious alleles from all populations

By strictly conserving locally adapted genes, it ensures homogeneity and consistent adaptation strategies across all subpopulations

It can introduce new alleles that may enhance adaptability under changing conditions or create maladaptive effects depending on compatibility with local adaptations

Antifreeze proteins preventing ice crystal formation inside cells.

Expanded gill surfaces despite increased risk of freezing.

Large fat reserves leading primarily to buoyancy rather than insulation.

Enhanced visual acuity not connected specifically to temperature regulation.

A new predator preys on only the smallest squirrels, causing larger squirrels' allele frequencies to increase over time.

A natural disaster drastically reduces the size of an elephant population, leaving only those who happened to be in protected areas.

Migration introduces new rabbit genotypes into an existing gene pool, increasing overall allele variety within that habitat.

Disease targets all frogs equally regardless of their genes, slowly diminishing the population size but not its genetic diversity.

The recessive lethal alleles would quickly disappear as individuals carrying them die before reproduction.

Natural selection acts against carriers of this lethal recessive gene reducing its presence each generation until it disappears completely.

The allele hides in heterozygous carriers who do not express the lethal phenotype but can pass the allele onto offspring.

All members of future generations would eventually become homozygous for this lethal recessive allele due to genetic drift.

It increases because new alleles are introduced from other populations.

It depends solely on natural selection acting on the introduced alleles' fitness benefits or drawbacks.

It remains constant as gene flow does not affect allele frequencies significantly.

It decreases because gene flow equalizes allele frequencies among populations.

Emigrating birds remove common alleles from the gene pool without changing allele frequencies significantly or altering overall variation markedly.

A stable migratory pattern maintains existing allele frequencies by consistently introducing and removing similar alleles each season without significant change over time.

Predators on the island preferentially hunting immigrant birds thereby reducing their numbers and maintaining original allelic proportions intact through selective pressures rather than gene flow effects.

Immigrating birds interbreeding with locals introduce new alleles into the gene pool, thus increasing genetic variation.

Decomposers

Tertiary consumers

Primary consumers

Secondary consumers

mechanical isolation

temporal isolation

hybrid breakdown

gamete isolation

The bottleneck effect increases genetic diversity, whereas the founder effect reduces it through selective breeding.

The bottleneck effect describes steady population growth, while the founder effect refers to rapid population expansion.

The bottleneck effect is due to natural selection, while the founder effect results from genetic drift.

The bottleneck effect occurs after a drastic population reduction, whereas the founder effect involves a new population started by a few individuals.

Allopatric speciation through geographic isolation leading to reproductive isolation

Artificial selection due to human interference with breeding practices

Genetic drift causing identical changes in both isolated populations

Sympatric speciation through polyploidy within one group on the same island