Why Don't I Look More Like My Siblings?

| 1 Comment
I have five siblings. The oldest two are my half-sister and half-brother, who are a result of my dad's previous marriage. From my parents marriage, there is my older sister, me, a younger brother, and a younger sister.  My sisters and I are all the same height. We share some common personality traits, and my-half sister and I both have very curly hair. But I don't look like any of them.

Granted, the picture above is not the best. I straightened my hair (it's not curly like my half-sister's), and it's not so focused. But you can see that we don't actually resemble each other very much.This is because your body is made up of cells. Every single cell in your body has two copies of <a href="http://curiosity.discovery.com/question/how-can-children-from-the">DNA (genes)</a>. So these two copies will form an X. One set of the DNA comes from your mother, and the other comes from your father. This makes sense that I might not look like my half-siblings, since we only share 1/2 the DNA  (from our father).

This doesn't explain why I don't look like my 'full' siblings, though. Without getting too complicated (since we're all non-science majors), people have <a href="http://genetics.thetech.org/ask/ask394">multiple copies of genes</a>. You might be carrying a blue-eye recessive gene and the brown-eye dominant gene, but only pass the brown one to your offspring. So imagine your parent has two versions of a gene. You will have a 50-50 chance on which one you will receive. But since I have 3 full siblings, who also have the same 50-50 chance, we only have 1/8 chance of all sharing that particular copy of a gene. It is virtually impossible that all of my siblings and I will share, by chance, the same copy of every single cell in our body.

Do any of you look a lot like your siblings? Or maybe you don't look alike at all? What do you think of this explanation?

1 Comment

I agree with your findings! I look nothing like my sisters from from the same patents, but i look a little like my older sister from my mom's previous relationship. It's cool how we don't look alike because we have a50% chance of getting genes from our mom or dad. I have a twin and I'm happy we don't look alike. Here's an article explaining how "identical twins" dont actually look alike. http://www.scientificamerican.com/article.cfm?id=identical-twins-genes-are-not-identical

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