Heritability

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A few things that I found interesting about the heritability concept were that it is expressed as a percentage. For example, if the heritability of a trait is 40 percent, that means that less than half of the differences among individuals in their trait are due to differences in their genes. In other words, the 60 percent is from differences in their environment. Another example is height; the heritability of height in adults is between 70 and 80 percent. On the other hand, religious affiliation is almost entirely due to environment, meaning there are no heritable traits.

As I have reached a stage where I feel like I am done growing (height wise) I have noticed that I am taller than my mom, but shorter than my dad, and falling right in between the both of them so the heritability is 50/50. An example of environment is religious affiliation, I was raised as a Christian, as was my mother, but it is still considered an environmental trait, not a heritable trait. Another environment trait is my choice of food, my mom loves salad, she will eat it everyday, however, I do not like salad at all, and therefore the trait of eating salad was not inherited.

One question that I have always wondered is why do some people think that I look Mexican, Latino, Puerto Rican etc. but I am mixed with black and white. I am not sure whether it is hereditary or a coincidence.


DNA.jpg

5 Comments

I initially didn't understand heritability very well, but you did a great job of explaining it! I think that your examples really enhanced the explanation of how heritability works.

I think the example of height that you gave was a great example of heritable traits. Because you received have of your genes from your mother and half from your father, you were a perfect mix between them. I also think you did a good job explaining how ideals and morals, things that you can change or are simply a state of mentality are not heritable but rather part of the “nurture” effect.

I like how you gave the example of the heritability of height between
your mom and dad, and how you are right in between. That shows
heritability pretty well, while you also clearly show that environment
also plays a role in how we develop traits. Our environment has nothing
to do with our heritability factors, which you clearly demonstrate with
the example of your food choices between you and your mom. You examples
are helpful in understanding this concept, so well done :) I also found
it interesting that heritability is done on percentages, but it makes
sense when you are dealing with only select options for traits, and
when you are set in determining what will or won't be inherited. As for
your last question about your appearance, I feel that is coincidence
mixed with your inherited traits because even though you are mixed, you
are mostly white, so the white trait is dominant to the black, but that
little part of black is coincidently making you appear to be of Mexican
decent.

Nice job, but you have to be really careful when you think about individual cases/preferences (as opposed to looking at how heritable traits are in a large number of people). Heritability is sort of a weird concept to wrap your head around, but what you said in the first place IS right: "if the heritability of a trait is 40 percent, that means that less than half of the differences among individuals in their trait are due to differences in their genes." The heritability of height is still around 60-80%, even for you (though you are right that you got half your genes from mom, half from dad); also, the fact that you don't like salad doesn't mean you didn't inherit salad-liking, since there could have been something in your mother's environment that caused her to like salad in the first place. It's good that you're all thinking about these ideas!

Heribility is something that affects how we look and what makes us different but many things like our culture and the way we think are solely based on the environment we were born. I was born into a Mexican catholic family but I know that those decisions we made for me by my environment.

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This page contains a single entry by fauds004 published on February 5, 2012 11:42 AM.

Neuronal Plasticity: Learning was the previous entry in this blog.

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