#population genetics

• Adelphogamy — A form of reproduction or fertilization method found in some plants, fungi, and lower organisms, consisting of the fusion of two gametes or two sexual cells originating from sibling individuals, directly related strains, or the same parent organism. This type of extreme biological inbreeding tends to fix existing genetic traits, limiting diversity and variability within the population.
• Allomixis — A biological phenomenon or reproduction mechanism characterized by the fusion or combination of genetic material originating from individuals with completely different origins, unrelated, or belonging to distinct genetic lines. This structural process plays an essential role in hybridization, stimulating increased heterozygosity within a population and preventing genetic defects linked to inbreeding.
• Allopatric — Relating to related species, populations, or organisms: occupying completely different geographic ranges, isolated or separated by natural physical barriers (mountains, rivers, deserts) that prevent gene flow and direct interbreeding. In evolutionary biology, allopatric isolation represents the primary structural mechanism triggering speciation, leading to the accumulation of independent genetic mutations in the separated populations.
• Allotype — A genetic variation or structural antigenic determinant within a protein or immunoglobulin (antibody) that differentiates individuals within the same species. This form of molecular polymorphism reflects the presence of different alleles at the corresponding gene locus, utilized as an essential biological marker in population genetics, forensics, and immunogenetics.
• Allozygote — A diploid organism or cell (zygote) in which the two alleles at a specific gene locus originate from completely independent and distinct ancestors, lacking a recent common origin (identical by state, but not by descent). This structural mechanism opposes the concept of an homozygote by descent (autozygote), serving as a baseline indicator of genetic variability and the absence of inbreeding within a population.
• Amphogeny — A biological property or phenomenon whereby an organism or parental pair produces offspring consisting of both sexes (both males and females) in relatively equal proportions; a structural type of sex determination that maintains a balanced Mendelian ratio in natural population dynamics.