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What Is Genetic Diversity?

Genetic diversity in a species allows it to adapt to changing environments.
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  • Written By: James Doehring
  • Edited By: Lauren Fritsky
  • Last Modified Date: 25 March 2014
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Genetic diversity is the variation of heritable characteristics present in a population of the same species. It serves an important role in evolution by allowing a species to adapt to a new environment and to fight off parasites. It is applicable to domesticated species, which typically have low levels of diversity. Studying genetic diversity in humans can help researchers form theories on human origins.

Living things contain in their cells the basic instructions, or blueprints, for their own development. Many of these instructions, which are called genes, result in physical characteristics that affect the way organisms interact with their environment. Variations in such characteristics within the same species give rise to genetic diversity. For a species to adapt to an ever-changing ecosystem, a significant level of variation must be present. Those individuals that possess favorable characteristics will go on to reproduce, while those that don’t do not tend to pass on their characteristics to many offspring.

Domesticated species often have low levels of genetic diversity. This is caused by the artificial selection, or preferential breeding, of crops and animals for traits that humans find preferable. While this can have positive short-term results, such as a richer harvest, low diversity among domesticated species poses risks. A newly-evolved virus or bacteria strand can invade a population of nearly identical organisms very rapidly. The protection that diversity generally offers in wild populations is lost in this scenario.

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The Irish Potato Famine between 1845 and 1852 was caused by a parasite invading a large population of nearly identical potatoes. The parasite was a water mold named Phytophthora infestans. This famine caused Ireland’s population, which was widely dependent on potatoes for food, to decrease by 20 to 25 percent.

Human genetic diversity typically varies based on the geographic location of a population. This has led biologists and anthropologists to study these diversity levels in the quest to understand human origins. Genetic diversity levels in Africa, for example, have been found to be higher than in many of areas of the world. Researchers have developed models of human origins from this evidence. The recent Out-of-Africa model, which suggests modern humans have a common origin in Africa, is one such example.

Biodiversity refers to the level of variation of all living things within an ecosystem. The importance of biodiversity to an ecosystem is analogous to the importance of genetic diversity to a population. Both forms of diversity contribute to the health and robustness of the larger system. When these levels of diversity fall, both systems are less able to adapt to a changing environment.

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Discuss this Article

Glasshouse
Post 3

@ Georgesplane- That sounds like exactly what I was looking for. One term down, thirty-nine more to go. Thank you for taking the time to answer. I love this site.

Georgesplane
Post 2

@ Glasshouse- I'm going to tell you what I know just to see if you are really going to respond. There are a few different types of diversity when you are talking about biological diversity. Genetic diversity, which was explained very well in this article, is one, the others are functional diversity, species diversity, and ecological diversity.

Functional diversity- The processes performed by different biological organisms that are necessary for a species, community of species, or ecosystem to survive. These are functions like nutrient cycling, energy transferring, etc. and can include both biological and chemical processes.

Species diversity- This relates to the number and relative abundance of a species within a community or ecosystem, rather than the genetic variation within a species.

Ecosystem Diversity- This is the variety of terrestrial and aquatic ecosystems found in an area, and how they interact with each other.

I hope this is what you were looking for.

Glasshouse
Post 1

When you are talking about biological diversity, is genetic diversity the only type of diversity that is considered? Honestly, I am taking a test in my ecology class next week, and I missed a couple lectures when I was sick one week. If someone could help me out, I'll say thank you.

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