Gene Flow and Migration

Gene Flow and New Traits from Migration

• Gene flow is the movement of genes between populations. It occurs through migration of individuals or the movement of gametes.

• Migration is a key driver of gene flow, introducing genes and potentially altering recipient populations' genetic makeup.

• Gene flow introduces new alleles (gene variations) into a population. Beneficial alleles can enhance fitness and adaptation to new environments.

• Gene flow can homogenize genetic variation between populations, leading to similar genetic makeup over time.

• Gene flow's magnitude depends on factors like distance between populations, migration frequency, migrating individuals, and selective pressures.

• Isolation reduces gene flow, fostering genetic divergence and potentially speciation.

• Barriers (e.g., geographical, reproductive) impede gene flow between populations.

• New alleles introduced through gene flow can change a population if they enhance fitness in the new environment.

• Genetic drift, random allele frequency shifts, often accompanies gene flow, especially in smaller populations. This combined effect significantly impacts population evolution.

• Gene flow's impact varies based on scale and mechanisms. Large-scale migrations have strong effects on regional genetic structures.

• Small-scale or localized gene flow plays a smaller, but still important, role, such as when related species share an area.

New Traits Arising from Migration

• Gene flow increases the gene pool's size and genetic variation, creating raw material for natural selection and potentially novel traits.

• Introduced alleles can be advantageous in recipient populations' new environments or niches. Natural selection favors these beneficial alleles, resulting in novel traits and adaptations.

• Migration-driven new traits include disease/pest resistance, tolerance to harsh conditions (temperature, salinity), and improved foraging.

• New alleles can be neutral, having minimal impact, or deleterious, reducing fitness.

• Gene flow, genetic drift, and natural selection interact to determine trait persistence.

• Increased genetic diversity fuels adaptations and evolutionary advancements. The mix of existing and migrant genes can create hybrid vigor (heterosis), speeding evolution.

• Migration shifts populations' genetic makeup, affecting phenotype expression. This leads to diverse inheritable traits, enhancing adaptations and allowing populations to exploit new ecological niches.