5 Questions: Starr on new book version of 'Ask a Geneticist

Courtesy of D. Barry Starr

D. Barry Starr fields questions about genetics from students both in classroom settings and through the website, "Understanding Genetics."

D. Barry Starr, PhD, is the director for the program, Stanford at the Tech, a collaboration between the Department of Genetics and the Tech Museum of Innovation in San Jose. The program teaches interested graduate students and postdoctoral scholars how to communicate science in an engaging, non-threatening way with museum visitors. Recently, the Stanford participants in the program compiled a book, When Will Broccoli Taste Like Chocolate?, which features their answers to some of the most interesting genetics questions that they have received. (The book was named for a question submitted to the group's website.) Medical school science writer Krista Conger talked with Starr about the program and the book.

Q: How did the idea of doing a book arise? Who wrote it?

Starr: The idea sprang from the "Understanding Genetics" website I have been running in conjunction with Stanford's Department of Genetics and the Tech Museum since 2004. The website has a section called "Ask a Geneticist" for which the public sends in genetics questions, and I or Stanford graduate students and postdoctoral fellows answer them. The website has become surprisingly popular with over 1.5 million unique visitors each year and around 200 to 300 questions each month — most of which are answered by email, and a few of which are posted online.

The idea for the book came from Dale Bodian, PhD, one of the Stanford at the Tech participants. Each participant has the chance to do a final project that synthesizes [his or her] newly acquired science communication skills into something that can have a more permanent, lasting effect on the program. Dale wanted to create a book version of some of the more popular answers to try to reach more people and to point out which answers we considered to be most important. What a Herculean task it turned out to be! Compiling, editing and publishing it was nontrivial, but I am so excited by the final result. This book is so much fun!

Q: Do you have a favorite section of the book?

Starr: One of my favorite sections in the book deals with something called chimeras. A chimera is really just a single person made up of two fraternal twins' cells. Basically, fraternal twins fuse together at an early enough stage that the cells get along and there are none of the issues associated with conjoined twins. You end up with one person with half of his or her cells from one twin and half from the other.

Sometimes you can tell someone is a chimera because of stripes that appear under ultraviolet light called Blashko's lines or because of something like having half the hair on your head one color and the other half a different color. Usually though, you can't tell someone is a chimera until you do a DNA test. Then all sorts of interesting things can happen.

It's great for TV (a CSI episode focused on chimeras), but it is also important in real life. For example, a woman was almost denied welfare because her DNA did not match her children's. Another woman who needed a kidney transplant found out her DNA didn't match her sons. They were both chimeras. And another similar case we talk about in the book is where a man with a bone marrow transplant almost gets away with a crime because being a bone marrow recipient makes the DNA in your blood — left behind at the crime scene — different from the rest of your DNA. How cool is genetics!

I also like the answers that deal with eye color, helping moms predict their children's eye color and comforting parents who wrongly believe that two blue-eyed parents can't have a brown-eyed child.

Q: Who is the program's target audience?

Starr: A big target audience for the program is elementary and middle school kids. We want to get them excited about science and maybe even to want to become scientists themselves. We accomplish this by having Stanford graduate students and postdoctoral fellows come down to the Tech Museum one morning each week to run hand- on genetics programs with the visitors. The mostly elementary and middle school visitors get to see that scientists are people like them and not some weird, scary person like on TV; they get to see that science can be fun, and they see that science isn't as hard as people make it out to be.

Another target audience is adults who are interested in genetics. We reach them mostly through our "Ask a Geneticist" website where, surprisingly, most of the questions come from adults. These questions mostly focus on physical characteristics like hair and eye color and on genetic disease. We try to show them where to find good information on the Internet and that, despite the jargon, genetics isn't as complicated as it looks. Hopefully they pick up enough skills to do a little exploring on their own after getting our answer.
The program started back in 2003 with a grant from the NIH through their Science Education Partnership Award program. The grant funded the" Genetics: Technology with a Twist" museum exhibition which is still going strong at the Tech and funded the Stanford at the Tech program, which is also ongoing. Since the grant ended in 2008, the program has been primarily funded through the Department of Genetics with a bit of help from the Howard Hughes Medical Institute.

Q: It's so important to make science fun. Can you remember a particular time or incident when you just really saw something click for a kid for the first time?

Starr: One of the great things about the programs we run is that we get to see this almost every day. We get to see a kid's eyes light up when suddenly natural selection makes sense or they begin to understand where they got their DNA.

One example I can think of happens with our PTC program. PTC is a bitter chemical that only some of us can taste. For the most part, it is controlled by two versions of a single gene. The "taste" version is dominant so usually people who can taste PTC have either two copies of the "taste" version or one of each while people who can't taste have two "can't-taste" versions.

It is surprising to me how few people (including adults) have really internalized the notion that we have two copies of each of our genes — one from mom and one from dad. But when we run this program with a family, you can see all the participants' eyes light up with the realization that this is the case. And then they can predict which versions of the genes everyone in the group has, why we might not be able to know for sure which genes some tasters have and how to figure it out. It's incredibly satisfying.

Q: How about a time when a kid asked you a question that either you didn't know the answer to or that made you think about science in a totally new way?

Starr: Actually, this is one of the really fun parts about the "Ask a Geneticist" section of the website. I get to explore aspects of science that I never got to before. When I started, I knew very little about the genetics of physical characteristics like hair and eye color. I've also learned about all the rare and not-so-rare exceptions to the rules we all learned in high school and college. I can tell curious people that tongue rolling or ear lobe attachment are not simple traits so please don't worry about your kids' earlobes or tongue rolling ability. I can also now propose rare ways that a parent with the blood type AB can have a type O child and lots of other real life rule breakers.

Answering people's questions also makes me think more deeply about how some things happen. For example, there has been a lot of talk for the last few years focused on the fact that chimps have 48 chromosomes and humans have 46. Many intelligent design people use this fact as an example of why evolution isn't real because they can't imagine how something like that could happen. After all, extra or missing chromosomes leads to problems like Down syndrome, and besides, two species with different numbers of chromosomes can't successfully breed (think donkeys, horses and their sterile offspring, mules).

This made me dig deeper into the science of chromosome fusion and to think about how something like that might spread. I found out that around 1 in 1,000 people have a balanced translocation where one chromosome is stuck to another. These folks are perfectly normal except they suffer from high rates of miscarriage. Now if two people with the same balanced translocation have kids together, one possibility is someone with the same chromosomes fused together. Now you have someone with the same amount of DNA just parsed out into a smaller number of chromosomes. Then you just need to propose a catastrophe where the survivors are mostly these new folks and voila, the species has a new number of chromosomes.

After we published this scenario on the website, a physician from China contacted us about a man in his practice who had 44 chromosomes because of something very similar to what I described. Basically his family had a certain balanced translocation, and after close relatives had children, this man with 44 chromosomes was born. He takes all of this beyond theory and shows that changes in chromosome number not only can but do happen.