Having extra copies of certain genes helps fish live in AntarcticaI've always loved weird creatures. Bacteria that can live in boiling mudpots. Weird tubeworms huddled around deep sea hydrothermal vents. Fish that live in below freezing water.

What I like is learning how these beasts have adapted to their incredibly harsh environment. More specifically, what changes have happened in their DNA that allow them to live where no other animal could.

In this blog I'll focus on those poor fish living in the waters off Antarctica. These waters are icy cold and the fish aren't warm blooded. Which means their body temperature is the same as the water around them.

Most biological processes do terribly under these conditions. Proteins don't fold right, enzymes work incredibly slowly, fats glob up. It is astonishing that these fish survive at all.

Scientists figured out back in the 70's that these fish evolved a special antifreeze protein to keep their blood from freezing. Since then they've done other experiments that show other adaptations to the cold too.

In a new study, scientists from the University of Illinois and the Chinese Academy of Sciences decided to take a look at as many genes and as much of the DNA of these fish as they could. What they found was that lots of genes are turned up in these fish compared to relatives that live in warmer waters. And that many of these genes are turned on higher because the Antarctic fish have extra copies of them.

The genes they found that were different made sense. For example, there are a bunch of genes that make proteins called chaperones. Chaperones help other proteins fold up right. In this cold, proteins need all the help they can get!

Also they found that there were more of the proteins that scavenge reactive oxygen species (ROS) in these fish. This makes sense because colder water has more oxygen.

O2 is a pretty nasty molecule that tends to create even nastier chemicals (ROS) that beat up on DNA and proteins. We all have proteins whose job it is to defuse these chemicals. These fish make more of these proteins.

A few years ago it would have been surprising to find that the way these genes made more proteins was by duplicating themselves. Not anymore.

As we look closely at the DNA of various creatures, we are finding that gene duplications (and deletions) happen a lot. Even in people.

For example, people from cultures that eat a lot of starch have extra amylase genes. (This gene makes amylase, a protein that helps breakdown starch.) Some people are resistant to HIV (the virus that causes AIDS) because they have extra copies of the CCL3L1 gene. And so on.

Our DNA is much less stable than we thought. Which is one way we can better adapt to our surroundings. I can't wait to see what they learn about those tubeworms!

Love is in the airI love you. Because you smell different than I do. Not quite Titanic or Casablanca or even Olivia Newton-John in Grease. But smells may be part of the reason why we fall in love with a certain person. At least that is what a new study argues.

We've known for awhile that animals find their "true love" partly through smells. One of the things they are sensing is whether the potential mate has a different set of MHC genes.

MHC genes are a big part of our immune system. These genes are used to create the huge number of antibodies that we each make to battle bacteria, viruses, etc. Everyone has a different set of these antibodies.

The more varied your MHC genes are, the more invaders your immune system can recognize and defeat. So two parents with very different MHC genes will have kids with immune systems that can recognize (and so defeat) lots of different kinds of bacteria and viruses. Parents with similar MHC genes will have kids with less varied immune systems. (This is a big reason why inbred animals are so sickly.)

Animals can tell about a potential mate's MHC genes through smell. And people might be able to do this as well.

Lots of experiments have been done where men or women sniff the sweaty t-shirts of members of the opposite sex to see which t-shirt smells better. If the potential mates are of the same ethnic group, the sniffers tend to prefer mates with very dissimilar MHC genes. If the potential mates were of different ethnic groups, the sniffers preferred mates with somewhat but not wildly dissimilar MHC genes.

The new study looked at a group of 30 European American couples from Utah and 30 Yoruba couples from Nigeria. Thankfully there was no sweat smelling involved. Instead the researchers compared the DNA between the spouses of each couple in many different places throughout their genome.

What they found was that for the Utah couples, the DNA around the MHC genes was much less alike than the DNA almost everywhere else. This did not appear to be the case for the Yoruba couples. This suggests that at least for these 30 couples from Utah, having a very different set of MHC genes may have been part of picking a spouse.

Why the difference between the Utahans and the Yorubans? It is hard to say without more data but one possibility has to do with how much of a role social factors play in picking a spouse in each society. Perhaps the European Americans are freer to choose a mate. If this is the case, then they might be more likely to follow some sort of biological imperative.

Another possibility is that this smell test is only a big deal if the potential mates are all very similar to start with. The Utah couples all had pretty similar DNA to each other to begin with. The Yoruba couples' DNA was less alike.

Of course, this is a total of 60 couples and so is in no way exhaustive and may be proven wrong tomorrow. But it adds to a growing pile of evidence that suggests how mate selection works at the biological level. And it shows the wide range of things we can learn about ourselves by studying our DNA in great detail. Maybe it even gives perfume companies some ideas too.

Guest blogger Lisa Croel of The Tech Museum in San Jose, CA sits in for Dr. Barry Starr this week.

I remember loving science class as a kid. The paper-maché messes, the bubbling baking soda, all of the wonderful experiments… I loved it all. Now, many grammar school kids are lucky to get 15 minutes of science education a week. Hardly enough time to get them imagining future careers as scientists, engineers and inventors.

Between the lack of time given to science education, and the structure imposed by curriculum standards, museums need to be part of the education equation. My boss has a saying: "Give random a chance." I love this quote because it speaks to the role informal educational resources like science museums need to be playing. By exposing young people to the experiences and programs in a museum, who knows what might really resonate and inspire?

For over 20 years, The Tech's Tech Challenge program has presented kids with an open-ended problem for which there is no one right answer. It forces participants to use their knowledge and ingenuity to solve the problem. For example, this year the Challenge (called Water Works) is all about moving water from a stream up to a village without electricity. There is no one right answer, and there are lots of ways to solve this problem.

Participants are 5^th to 12^th graders who will work in teams of 2-6 to explore solutions to solving this real world problem. Along the way, they will hit some roadblocks and come up with some duds. And that's OK because it is here that kids will learn that failure is an important part of problem solving. We have a great quote etched into a wall on the outside of The Tech from Intel co-founder and philanthropist Gordon Moore that says, "If everything you try works, you are not trying hard enough." Through failure, many of the Tech Challenge teams will come up with a far superior solution.

This year we're going international for the first time by partnering with the City of San Jose's Sister City program. On the final event day, where all of the teams come together to present and demonstrate their solutions, we'll be webcasting in teams from far-away locations, and look forward to seeing and hearing how kids from other countries have tackled the challenge. Hopefully the involvement of other cultures will drive home how important it is to be inclusive to come up with better ways to solve problems.

I just looked at the U.S. Census Bureau web site for the latest world population number, and today there are 6,650,846,379 people on Planet Earth. One in five people on Earth don't have access to safe, clean drinking water, which means that 1.3 billion people are suffering from lack of water. As this year's Tech Challenge participants work on solutions to a global water problem, I hope they get excited (or more excited) about science and remain engaged, even they don't get to study it much in the classroom.

Lisa Croel is the Marketing Director at The Tech Museum of Innovation in San Jose, Calif.