Decreasing genetic diversity of animals

Decreasing genetic diversity of animal breeding stock
Excessive use of domestic animals for breeding purposes
Excessive inbreeding of domestic animals
Genetic impoverishment of animals through domestication

Nature

Animal breeding programmes, designed to produce animals with hardy high-yield characteristics after careful selection, can be counter-productive. The more successful a variety is, the more likely farmers are to choose the hybrid in question. An entire society may come to depend on a small range of highly selected varieties. When a new or mutant form of a disease appears to which the favoured hybrid has no inbred resistance, an entire breeding stock may be destroyed.

Both male and female animals which are finely bred or which have particularly commendable points from a breeding point of view, may be overused for breeding purposes, giving rise to inferior progeny or infertility. Females of certain species may be mated consecutively when it may be better for them to have a resting period between pregnancies. Males may be overused for financial reasons, or for their prowess or virility, or because of their fine breeding or special qualities. Males may be used too often with the same herd or the same individual animals. They may be overused for artificial insemination purposes, where demand for the services of sires of high merit is extensive, and where one ejaculation may be extended to 100 or more services, almost on the level of mass production.

Inbreeding of domestic animals is a common practice to improve stock and to preserve qualities found in one or two exceptionally fine animals. However, the effect of inbreeding also serves to increase the proportion of defective, weak, slow-growing animals, and unless the method is used very selectively, especially with species that are normally cross-fertilizing and outbred, these characteristics will predominate. Reasons for excessive inbreeding include lack of due care, general inexperience, overzealousness, and financial rewards.

Background

The global decline in animal genetic diversity first gained attention in the 1970s, as conservationists observed alarming losses in wild and domesticated species. Subsequent research linked habitat destruction, overexploitation, and industrial agriculture to shrinking gene pools, raising concerns about species’ adaptability and ecosystem resilience. International initiatives, such as the Convention on Biological Diversity (1992), have since underscored the urgency of monitoring and preserving genetic resources, highlighting the problem’s far-reaching ecological and economic implications.

Incidence

The decreasing genetic diversity of animals is a phenomenon observed across continents, affecting both wild and domesticated species. Studies indicate that over 28% of assessed animal species face declining genetic variation, with isolated populations and intensive breeding practices accelerating the trend. This reduction undermines species’ resilience to disease, environmental changes, and long-term survival, making it a significant global conservation concern.
In 2022, researchers reported a marked decline in genetic diversity among African cheetahs (Acinonyx jubatus) in Namibia. Genetic analyses revealed that habitat fragmentation and population bottlenecks have led to dangerously low genetic variability, threatening the species’ future adaptability and survival.

Claim

There is an impending threat of reduction or disappearance of sources of genetic germ plasma. The introduction of exotic species and genetic yield research have put pressure on a number of indigenous species, subsequently reducing their numbers or destroying them completely.

Counter-claim

Concerns about decreasing genetic diversity in animals are vastly overstated. Nature has always adapted through survival of the fittest, and species naturally come and go. Human progress and development are far more important than worrying about minor genetic variations in wildlife. Resources should be focused on issues that directly impact people, not hypothetical future problems in animal populations. The alarm over genetic diversity is simply not a pressing or significant problem.