QUEST Community Science Blog

There is a lot we don’t know about our DNA and how it works. While there seems to be news every week about genetics, scientists are still in the early stages of finding out what effect our genes have on us (check out this post from another QUEST blogger, Dr. Barry Starr). That’s what the researchers at the Canine Behavioral Genetics Project are doing. But in this case, they’re looking at dog DNA.

It turns out that human intervention in the form of hundreds of years of dog breeding has created a unique genetic experiment. Because purebred dogs are in essence closed gene pools, it’s much easier for scientists to compare of DNA of dogs within a breed. The Canine Behavioral Genetics Project is doing this to find the genes that are associated with behavioral disorders, like anxiety and fear. They also hope to use that information to find the genes in humans that are associated with similar disorders.

Millions of problematic dogs are given up each year in the U.S. And while the UCSF team definitely believes that training is a huge part of dealing with dog behavioral disorders, they’re also hoping to understand the genetic influences. Many owners are starting to use medications to help treat these problems, like doggie Prozac. But Melanie Chang, a member of the UCSF team, made a good point to me. Owners tend to think their dog’s problems are the owner’s fault. Sometimes there are other forces at work.

Listen to “Doggie DNA: Human Genetics through Dogs” online, as well as find additional links and resources. Also, check out the photo set with behind-the-scenes photos.

Lauren Sommer is an Associate Media Producer for QUEST.

I love my cell phone. We have a serious relationship. One that may be biologically predetermined.

Let me explain. On New Year’s Eve I brought my phone with me to San Francisco’s Ocean Beach, where I traditionally go, rain or shine, to watch the year’s last sunset. I was by myself, but I wasn’t alone.

Oh no. I took snapshots of shimmering colors on the waves and sent them to faraway, landlocked friends who miss the sea. Another friend called to say she was also watching the sunset from her rooftop. Text messages flowed in.

I was connected.

Well, duh,” you could say.

And this “duh” is exactly what seemed kind of profound: we take communication for granted. Of course we can talk to each other and share things with each other. And of course we create new devices to make talking and sharing easier. Of course.

But why do we do this, seemingly to no end? And why is it that communication is such a vital and defining aspect of our experience as humans? Why, really, do I love my cell phone so much?

I think it’s genetic.

It’s probably not news to most of you that we humans appear to be wired to talk to each other. We’ve got that FOXP2 gene that keeps making the news, contributing to our linguistic capacity. In fact, many researchers believe that language was central to our success as a species and allowed a small group of humans to expand across the globe about 50,000 years ago.

Our genetic design for interaction seems to go beyond talking amongst ourselves. A University of Michigan study slated to be published next month found that social interaction has a positive affect on memory and on cognitive functioning. The people who had the most conversations with others seemed to be the sharpest, and this was particularly true among young people. This may mean that more socially-oriented humans had a bit of an advantage over those who tended to keep more to themselves.

We may be such social animals that we’re even hard-wired to simply need company. After all, isolation is one of the most universal methods of punishment. Another set of researchers at the University of Illinois at Chicago found that mice isolated from their comrades have lower levels of hormones that control anxiety, depression, and aggression. They believe that these responses are similar in humans. In other words, it’s possible that our brains keep us happier and functioning better when they’re interacting with other brains.

It makes sense that our predecessors who figured out how to play well with others and share their thoughts were the ones who got the best shot at passing on their genes. And it’s no wonder our species devotes such enormous reserves to inventions that make communication easier. The most basic systems of rock painting and alphabets have allowed groups to share stories or warn others of impending trouble. And creations that help disseminate these symbols–papyrus, the printing press, even the simple pen and paper–have had a major impact on how we exist with one another, as individuals and as societies.

These days, many of our communication technologies have gone beyond “watch for hungry bear” or “here’s my idea” into doing a kind of doubly-human duty. We not only use technology to convey thoughts, but also to extend our opportunities to create bonds with other people and to form social groups. Thus the popularity of the likes of Facebook, personals ads, and Flickr. In fact, if you leave a comment about this little ditty I’ve written, you’ve hopped on this double-duty train by becoming a part of Quest’s blogging community.

And so now, as my thumbs feverishly tap out text messages, I see my cell phone as more than a gadget. It’s the latest cousin of cave drawings and hieroglyphics. What it says about my own evolution I’m not quite certain. But no doubt my wireless admiration results from something buried in my chromosomes.

Robin Marks is a journalist and science writer who current serves as a Multimedia Projects Developer for the Exploratorium in San Francisco, CA.

latitude: 37.7595, longitude: -122.51

Bobby is more likely to be gay than Greg.

Last blog I talked about some studies that link homosexuality and genes. The most powerful studies are those that compare identical twins to fraternal twins. These studies show that both twins in an identical pair are more likely to be gay than are both twins in a fraternal pair. Since identical twins have the same DNA, this suggests that something genetic is going on.

But no study showed that if one identical twin was gay, then the other one was always gay as well. We’d expect both twins in an identical twin pair to share a purely genetic trait 100% of the time. Because they don’t, the environment definitely plays a role. But not like you might think.

By environment I don’t mean certain family situations (although these sorts of factors probably contribute as well). What I am referring to are environmental factors that can affect brain development. Factors like viruses, hormones, or maybe even antibodies.

We know, for example, that the more older brothers a man has, the more likely he is to be gay. Even if he doesn’t live with the older brothers.

This suggests that something biological is going on. It is as if the mother’s body remembers how many sons she has had. One way this might happen is through her immune system.

Perhaps when a mother has a son, she makes antibodies to something having to do with carrying a male child. The more sons she has, the more antibodies she makes. At some point, she makes enough antibodies to affect brain development and the younger son is now gay.

Of course, not every youngest son is gay– he is just more likely to be homosexual. Other factors have been reported to increase the chances that someone is gay too. These include being left handed, having a counter-clockwise hair whorl and maybe even different finger lengths. All of these traits are associated with differences in brain development.

There are apparently many paths to a homosexual brain. This isn’t surprising as human sexuality is much too complex to be due to a single gene or environmental factor. Most likely, it is the result of many factors all working together.

Some gay men may have inherited genes that made environmental factors more likely to affect their sexuality. And some gay men may have been exposed to multiple environmental effects that affected their sexuality despite their genes.

I think you can appreciate how these kinds of complex interactions can make finding “gay” genes incredibly complicated. And why it is hard to pinpoint the environmental effects that contribute to becoming homosexual as well.

Dr. Barry Starr is a Geneticist-in-Residence at The Tech Museum of Innovation in San Jose, CA.

latitude 37.3316, longitude -121.89

Gay Pride Parade in BrazilA big federal study is underway to identify the specific DNA changes that contribute to being a homosexual. Note that scientists are not investigating whether or not being gay is genetic. The evidence is already pretty strong at this point that there is a genetic component to being gay. What they are looking for are the specific changes.

For example, one study showed that if one identical twin was gay, then the other was 50% of the time. If the two brothers were fraternal twins, then the odds dropped down to 22%. And if one brother was adopted, the odds were only 11%.

Another more comprehensive study gave similar results with both twins in an identical twin pair being gay around 32% of the time as compared to 13% of the time for fraternal twins. Lots of other studies have been done that show the same trend even if they don’t have the exact same numbers.

These results strongly suggest genes are involved because identical twins share the exact same DNA. If both twins in an identical twin pair have some trait in common more often than do fraternal twins, then odds are that genetics plays a role.

These twin studies show that being gay is at least partly genetic. So the new study is really just looking to explain explain the older results.

That said, I am torn about whether I want this study to succeed or not. If it is successful, that’ll shut up all those people who maintain that sexual preference is purely the result of personal choice. In my opinion, quieting those folks is a good thing. But finding the gay gene(s) may have unintended consequences. Some people may see being gay as akin to a genetic disease like cystic fibrosis or sickle cell anemia. As something to be minimized through carrier screening, embryo selection, or even abortion.

Scary, but I have heard people say things like this. Just the other day someone asked a friend of mine if homosexuality was genetic. They weren’t merely being curious. They were hopeful that there was a gay gene so that homosexuality could be eliminated from the human population at some point. Yikes!

And that was here in the San Francisco Bay Area. Who knows what they are saying in Wyoming or Texas. Do we want to find the gene(s) responsible for homosexuality? Or are some things better left unknown? Comment below.

Dr. Barry Starr is a Geneticist-in-Residence at The Tech Museum of Innovation in San Jose, CA.

latitude 37.3316, longitude -121.89