Science Rules! with Bill Nye on Smash Notes

Heredity & Me

Science Rules! with Bill Nye

You've probably heard someone say, "She takes after her father." But what does that really mean? How do we inherit certain traits and characteristics? Writer Carl Zimmer joins us to answer your calls about what heredity means, how it plays out, and whether you should consider taking a DNA test. His book, She Has Her Mother's Laugh, is now available in paperback.This episode is sponsored by Turo, KiwiCo (, and MagellanTV (

Episode notes last updated on June 22, 2019 15:43


In this episode

Smash Notes summary for this episode

What inspires Carl Zimmer to write books?

He likes to explore things we know a little about, but don’t think about. Carl Zimmer likes to write books about things that he can to investigate. As he says when investigating a topic, the bottom falls out.

What was the inspiration of Carl Zimmer’s book, “She Has Her Mother’s Laugh”?

When he was considering the topic of heredity, he thought about what’s normally talked about with heredity. We talk about it all the time as we make connections when different generations having similar traits.

How do genes mess up some things with heredity?

It’s because we tend to think that genes and things like laughter are the same, but they’re not. We inherit genes, carbon copies of genes from our parents, but other things do get carried down.

How are nature and nurture connected?

Overall, no one knows what these genes do or how they connect, but the heredity connection is evident. They all weave together and influence each other.

Why are redheads always pale?

It’s because the variants that can make you have lighter hair also make the pigment of your skin lighter.

What are epigenetics?

In addition to inheriting genes, you inherit the molecules around the genes that control whether they’re turned on or off. These molecules can also change due to experiences. Yet, the evidence and sample size in humans is tiny and cannot be proven completely true.

Did I inherit my artistic abilities from my parents?

Unfortunately, science cannot answer this for someone individually. Science can look at averages from lots of people. Genes play a role on average, but we can’t specify this gene in relation of heredity from a parent.

How do we know height plays a part in heredity?

According to Zimmer, scientists are still struggling with this curiosity. You can pinpoint the genes that influence your height, but there are thousands of them that have been linked. It’s the combination of genes, not just what’s on our DNA.

Why are we taller now than people of previous centuries?

It’s not because of genes, but it depends on our diet, clean water, and medicine.

Do personality traits change?

Yes, there are lots of things in life that can influence a person’s personality. Scientists are also looking at hundreds and thousands of people taking personality tests to see if they share the same genes.

Why do people go on Family Feud?

According to Bill Nye, there’s a belief or presumption that there’s a connection between family members that they would share. On the show, it would be discovered. Zimmer states it’s because we are adapted to care more about our family.

What happens when you make a carbon copy?

When you make a carbon copy, the copy is actually imperfect. The letters in DNA that are being passed down are not the same, but like a sampling of the DNA of our ancestors.

Is handedness inherited?

Zimmer says that being left-handed or right-handed seems to be inherited, but scientists cannot find the genes to prove it.

Is IQ inheritable?

It is partly inheritable because it's about 50-70%.

Can you see a gene under a microscope?

No, you can't.

Is it a good idea to buy genetic test kits?

Zimmer states that yes, it is good to buy the kits, but only if the person is willing to put in the work to understand the results. This includes reading and looking up the results instead of just looking at them.

Is it true that baldness genes come from our mother’s father?

There are lots of genes that are involved in hair, so it doesn’t necessarily rely on that speculation anymore. Color blindness is applicable since it’s on the X chromosome.

Is it true that twins skip a generation?

No, this is false.