interbreeding, offspring, predation, intermarriage, polyandry, dystocia, outbreeding, outcrossing, breeding, lungworm, overfeeding, hermaphroditism, introgression, crossbreeding, overpopulation, homozygosity, recessive gene, breeders, rhesus, asexual reproduction, mutation, bloodline, polyploidy, endogamy, lynxes, extinction, undescended testicle, endometritis, canids, herd, hybridization, parturition, outcross, lineages, onagers, woodrat, cryptorchidism, aneuploidy, heredity, parthenogenesis, genetic defect, ursus arctos horribilis, dimorphism, genetic abnormality, acidosis, assortative mating, malformations, tapeworm infection, translocation, fecundity, pygmy chimpanzee, parasitism, mutant gene, zebu, genetics, toxoplasmosis, tameness, deformity, tuataras, rheas, genetic mutation, alleles, oestrus, bustards, canis familiaris, recombination, guanacos, lameness, childlessness, prairie vole, hybridisation, infanticide, dingoes, stillbirth, pasturage, masculinization, stereotypy, banteng, meadow vole, coevolution, saiga, cretinism, heterosis, babirusa, subspecies, progeny, herpesvirus, consanguineous, sifaka, mandrills, bdelloid, estrous cycle, foals, mating, prairie rattlesnake, musth, trematodes, chimeras, lagomorphs, seladang, domestication, peccary, attrition, desiccation, degradation, erosion, experimentation, frustration, impoverishment, intermingling, defoliation, leaching, alienation, enrichment, exhaustion, fragmentation, retrogression, undermining, blurring, crowding, debilitation, barometric, barometrical, molal, regression, trichromatic, absorption, adiabatic, aerodynamic, allometric, anisotropy, arrhenius, aversion, ballistic, binomial, bistatic, broadening, coriolis, correlation, coupling, cycling

breeding, inbred

conjugation, coupling, mating, pairing, sexual union, union