Genetic diversity why is it important

Gene banks that save millions of seeds from around the world, botanical gardens that showcase dazzling plant collections and pastoralists who raise traditional livestock breeds all contribute to preserving biological information for the future.

With the changing climate, disease epidemics and other environmental risks factors we face, genetic diversity could be the difference between survival and extinction for many species — including, eventually, our own. More information: Updated zero draft of the post global biodiversity framework Global Biodiversity Outlook 5 FAO: State of biodiversity for food and agriculture Phys.

Water and food, climate regulation, even the interactions between human spirit and nature. Still, history shows us that most tribes understood that mates should be selected from other tribes and developed rituals to accomplish this. There have of course been situations where this has been difficult if not impossible and the resulting population from close breeding is more likely to pass on an otherwise uncommon allele. But it can happen anywhere breeding takes place within a small community.

In these situations, children are more likely to inherit two copies of a recessive gene that leads to genetic disease. An example is the Amish community where members are forbidden to marry outside the faith. Many Amish have extra fingers or toes, a symptom of the genetically inherited disease, Ellis-van Creveld syndrome [7]. While there have always been alterations in the natural world that split populations, like rivers moving, mountains forming, and glaciations, species have continued to thrive.

In some instances, this has led to the development into new species once separated into distinct environments. The fragmentation of species is hastening dramatically today as the human population explodes. In the plant and animal worlds, genetic diversity is threatened by the disruption of habitat due to human expansion.

Urban sprawl and development are shrinking and isolating populations across the world. Even in the human population, sometimes alleles simply disappear when they are not manifested over time. In the plant world, a similar phenomenon is taking place, only at a very rapid pace due to human intervention.

We are losing crop diversity as agriculture has become industrialized and agribusiness focuses on cost-efficiency by mass producing just a few varieties of crops. Wild animal populations are suffering from habitat fragmentation, and from being hunted and captured.

They are no longer able to find mates outside their inner circle. Nor is it infrequent for exotic wild animals to be captured and raised in zoos. Attempts to breed animals held in captivity have had varying success with one of the problems being the small number of potential mates. Zookeepers make deliberate attempts to rotate individual animals into and out of a population in order to bring in new genes.

When a species can only reproduce within a small or isolated population of organisms, individuals of that species may be forced to breed with close relatives which simply creates a more uniform and smaller gene pool for the species.

Inbreeding , as the phenomenon is called, makes species weaker and more susceptible to diseases. Apart from humans, where incest is considered illegal in most countries and where even marriage among cousins is often prohibited, the concerns related to inbreeding are very well illustrated in the case of some of our favorite pets. Genetic diversity of plants, animals and other living organisms is what enables them to survive and thrive in this world. The capacity of species to adapt to new circumstances, whether this is resource scarcity, a changing environment or other disturbances to their natural environment, depends on genetic diversity.

The greater the variation in genes, the more likely is that individuals in a population will possess the differentiated genes which are needed to adapt to an environment. The theory of natural selection suggests that it is this variety of genes that allows species to evolve, adapt and propagate successfully. Genetic diversity helps maintain the health and vigor of a population to resist infectious diseases, pests and other stresses.

And it better equips a species to survive in a changing environment. Consider that we may be facing a markedly hotter world. Darker eyes have more pigment to protect against sun damage and ultraviolet radiation than blue or green eyes [8]. Having these traits available may prove to be an advantage for survival. Having a high homozygosity percentage of two identical alleles of a particular gene is problematic.

Many deleterious alleles are recessive and a different dominant allele would mask it so that the disease does not manifest. However, individuals with low genetic diversity are more likely to inherit the deleterious recessive alleles and suffer of the disease. There are some traits like, for example, the allele for sickle cell anemia which actually protects against malaria in heterozygotes but causes a deadly disease in homozygotes [10].

Large populations tend to have high levels of genetic diversity. A focused initiative has been applied to raise the profile of genetic diversity in line with the two other components of living diversity — species and ecosystems.

To achieve this, the 'Conservation genetic resources for effective species survival' CONGRESS project has successfully facilitated access to a huge scientific knowledge base.

The website includes a database of the genetics of threatened European wild species and a sample planning tool to assess the power of experimental design. A decision-making tool helps formulate genetic approaches to a management problem.

Educational downloads include a series of 'How to' leaflets and a 'Knowledge pack' to answer management problems. Information on the 'Decision-making Tool' for end users includes explanatory text and useful links as well as connections back to the relevant management topics. The databases for the web portal feature chosen species. Credit: Katrina Liebich, U. Fish and Wildlife Service.

Public domain. Genetic diversity and the portfolio effect can help buffer species against global change. Take Pacific salmon as one example. Salmon have a wide range of life history strategies, perhaps most evident in the variation in spawning migration timing. Evolutionarily, different spawning runs arose because in certain years environmental conditions favored the success of offspring spawned at certain times.

The stability of salmon abundances in southeast Alaska is often attributed to this high level of diversity. With climate change, certain salmon life history strategies are frequently more favorable. Indeed, there is already genetic evidence of long-term changes in migration timing of adult salmon in the region see Kovach et al. The greater the genetic diversity, the greater the opportunity for resiliency to future climate change.

When it comes to fish conservation in an era of global change, genetic diversity is like that diversified financial portfolio. If you bet everything on one strain, you could end up with another potato famine.