Carl Zimmer

It's not like just because you look like one of your parents, you are more like them in some sort of deep way.

You inherit 50% of your genes from one parent, 50% from the other.

So genetically speaking, you're just a perfect 50-50 split between your parents.

Well, heredity is a word that's been around for a long time.

I mean, the ancient Romans would talk about heredity, and their word was hereditas, and it referred to the rule's

by which people inherited stuff from each other.

And we still talk about inheriting money or houses or what have you.

But by the 1800s, people were thinking about other things that people inherited.

Why was it that diseases seemed to run in families, for example?

So people started to look for explanations for why each generation inherited

resemble the previous generation in different ways.

And that's what led to the discovery of genetics.

But that doesn't necessarily mean that just saying like, oh, it's just genes is really the full answer to heredity.

Actually, that's just really kind of the starting point for understanding what heredity is and why it means so much to us.

You know, I think we have developed an idea that if we want to understand our own identity and who we are, we have to look to the past, that somehow we can zero in on some ancestor to figure out how our lives ended up the way they are.

And, you know, so this is what drives the huge genealogy business today and the direct-to-consumer genetics testing.

I mean, we want to

We want to find out, are we 27% Irish?

And can we identify our great-great-great-great-great-grandmother?

And maybe there's something like us in that person.