To understand the benefits and costs of inbreeding, I think that it is important to define the word. Inbreeding is, "the interbreeding of closely related individuals especially to preserve and fix desirable characters of and to eliminate unfavorable characters from a stock" (Merriam-Webster). So, basically, it is when a parent/offspring, brother/sister, and half/brother and sister copulate. First cousins and second cousins are considered inbreeding in humans, but in animals, people have a hard time drawing a line when it is considered inbreeding or outbreeding (Massey et. al). When looking at the given definition, you can begin to pull out the benefits of inbreeding. Preserving and zoning in on a specifically helpful trait can be very useful for an organism. Inbreeding also helps to get to the desired trait faster. Dogs are a common example of an animal that is interbreeded a lot. They make for cute animals, but a lot of these animals have health problems later on in life.
Although there are some benefits of inbreeding, I believe the costs outweigh them. To demonstrate these, I picked the cow as my example, as most of us are affected by these animals. Inbreeding is actually allowed with these animals, but it is recommended that they should only share 6.25% of their genes with the other animal they are being bred with, (so, breeding with a cousin instead of an immediate family member). If the cows share any more genes, problems start arising including lower productivity, fertility problems, reduced longevity, and a higher frequency of hereditary abnormalities (LIC). Abnormalities occur when both of the parents have a recessive gene for this abnormality. Usually, having a recessive gene for abnormality isn't a big deal. The possibility of an organism breeding with someone else who has this exact gene is low. However, when an organism breeds with a close relative, the relative most likely has the recessive gene, which will then lead to problems in the offspring.
If you look at this website that I attached below, you will get to read about some cool tools that this company uses to make sure that they are not inbreeding their cows too closely. Happy, healthy cows are better for everyone in the long run!
(https://www.lic.co.nz/products-and-services/artificial-breeding/inbreeding-and-recessive-genes/)
Sources:
LIC. “Inbreeding and Recessive Genes.” LIC, https://www.lic.co.nz/products-and-services/artificial-breeding/inbreeding-and-recessive-genes/.
Massey et. al. “Inbreeding: Its Meaning, Uses and Effects on Farm Animals.” University of Missouri Extension, https://extension.missouri.edu/publications/g2911.
Merriam-Webster. “Inbreeding.” Merriam-Webster, Merriam-Webster, https://www.merriam-webster.com/dictionary/inbreeding.
The cow example is really interesting Emmary, 6% doesn't sound like a lot but I guess any recessive mutation could cause problems to the offspring and further down the breeding line.
ReplyDeleteI like that you included the example of the cows to demonstrate the costs of inbreeding! The website is a cool tool and it's always interesting to see the study of evolution applied in other fields.
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