A break from science
November 19, 2008
Sleep well
November 18, 2008
New research shows that sleep helps our minds to remember the information it has accumulated throughout the day. Subjects were tested using a video game and found that they performed better the morning after they were trained on the game than they had the night before, just 12 hours after training. The scientists claim that this phenomenon holds true for more complicated tasks as well. So, if you are trying to learn something, whether it be speaking Portuguese or Kung Fu fighting, sleep on it.
Even if your parents aren’t fighting, their genes may be
November 15, 2008
In light of my recent post on genetic compatibility in harvester ants, I found this New York Times article fascinating. Dr. Bernard Crespi of Simon Fraser University in Canada and Christopher Badcock of the London School of Economics have proposed a new theory for the development of mental disorders, and it’s based on an inherent disagreement between the genes of your mom and those of your dad.
In a Novel Theory of Mental Disorders, Parents’ Genes Are in Competition
Excerpt: Their idea is, in broad outline, straightforward. Dr. Crespi and Dr. Badcock propose that an evolutionary tug of war between genes from the father’s sperm and the mother’s egg can, in effect, tip brain development in one of two ways. A strong bias toward the father pushes a developing brain along the autistic spectrum, toward a fascination with objects, patterns, mechanical systems, at the expense of social development. A bias toward the mother moves the growing brain along what the researchers call the psychotic spectrum, toward hypersensitivity to mood, their own and others’. This, according to the theory, increases a child’s risk of developing schizophrenia later on, as well as mood problems like bipolar disorder and depression.
Ligers and tigons and bears! Oh, my!
November 13, 2008
Unicorns, mermaids, griffins, centaurs… mythology has long been inspired by the combination of two or more species into one spectacular character. More recently, humans have been deliberately breeding animals of different species to craft modern hybrids, such as a cross between a male tiger and female lion to create the world’s largest cat, the liger or tigon. Or the leopon, which sports the patterning of a leopard with the head and beautiful mane of a male lion. These unique creatures are undoubtedly interesting, but they are manmade. Do matings between different species happen in the wild?
In fact they do. A recently publicized case is that of the grizzly and the polar bear, which may be hybridizing more frequently as a result of global warming. Although still quite controversial, the theory is this: as the earth continues to warm, the ice that comprises the polar bear’s habitat is thinning, forcing the bears farther inland, where they come into more contact with their relatives, the grizzlies.
Regardless of the cause, such wild hybridizations are far from the norm. This is because hybridization is almost always detrimental to the offspring. Even if the offspring survive, they are often less fertile than their purebred brethren. As a result, individuals that hybridize contribute fewer progeny to future generations than those that do not, and mechanisms for avoiding hybridization evolve.
Thus, hybridizations observed in the wild have often been described as ‘mistakes.’ However, in the last ten years or so, scientists are beginning to recognize that hybridization is not always bad for all species. Once such case is the spadefoot toad. In these toads, the benefits of mating with individuals of another species sometimes outweigh the costs, such that hybridizing may be the preferred mode of reproduction!
Two species of these toads (Spea bombifrons and Spea multiplicata) are both found in the southwest US, where they risk hybridizing and creating offspring that of lower quality than purebred offspring. Hybrid males, for example, can be sterile, and hybrid females produces fewer eggs.
However, S. multiplicata toads develop faster than S. bombifrons, as do the hybrid offspring of these two species. Thus, if an S. bombifrons female wanted to produce tadpoles that metamorphosed sooner, all she would have to do is find an S. multiplicata male to mate with.
So the question is: when is it more beneficial to have slower developing, more fertile offspring, and when does it pay to hybridize to produce quickly developing, less fertile broods?
The answer is in the pond. Both species of toads develop in small ponds that often dry up before the tadpoles have a chance to fully develop. The smaller the ponds, the quicker it dries up, and the greater the benefit to producing rapidly developing offspring.
As it turns out, the depth of the pond seems to be the basis for the female S. bombifrons decision of whether or not to hybridize with S. multiplicata. S. bombifrons females were much more likely to hybridize in shallower ponds than they were in deeper ones. Thus, females appear to be choosing whether or not to hybridize depending on the environment in which they find themselves reproducing!
So, at least in this case, hybridization may actually be adaptive. Whether or not our manmade hybrids are benefiting from our insatiable creativity is another story.
Notes:
Photo credits 1,2: Top 10 Hybrid Animals
For more information on hybridization
For more information on grizzly-polar bear hybrids
For more information on the spadefoot toad story:
Pfennig K. S. 2007. Facultative mate choice drives adaptive hybridization. Science 318:965–967.
A Politcal Swing on Science
November 13, 2008
Is there a link between obesity and policy? Read Olivia Judson’s thoughts.
Learning from Nature : An interview with Erika Check Hayden
November 6, 2008
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| Photo taken from Hayden’s website |
I have to admit, I was a little intimidated by the prospect of interviewing Erika Check Hayden. Not that much older than I, she has already established herself as a prominent figure in the science writing community. With an undergraduate degree in biology from Stanford University, Hayden began writing for the Stanford Daily and the Stanford Alumni Magazine. She then worked for Newsweek magazine in NYC, covering science, medicine, and other breaking news events. In November 2001, she began her current position with the journal Nature, writing about new technologies, environmental issues, and other science news.
We had arranged to meet at the welcome reception at the 2008 National Association of Science Writers conference in Palo Alto, CA. We found a small room, away from the hubbub of the conference activities, and sat down to talk about her transition from the world of science to the world of writing about science.
How does your biology background affect the way you write about science?
Having a biology background definitely grounds me in some of the history of science and the scientific method and believing in the way that science works. If I didn’t have that, it might be a little harder to kind of get into the heads of scientists and the way they think, and I think that’s maybe a challenge people have if they don’t have a science background. I love science, but I also know it’s a very human endeavor so I don’t look at scientists as different from other people necessarily. I think that’s a help because there are human motivations going on, and it helps you put things in context. I think that’s very helpful for being in science journalism.
But because you’re already familiar with all the language and the jargon and the technical words, that stuff might not stand out as much to you as much as it would if you didn’t have a science background. Even though I’m writing for Nature, my audience is gonna have chemists and physicists in it, and it’s kind of a balance to figure out what I can get away with that they’re still going to understand but that people who are experts in the field are not turned off by because it’s so ridiculously elementary. So that’s an interesting challenge of being somewhere like Nature or Science. I think it would be different if you were at a generalist’s newspaper.
What was your first published story about?
It’s funny because I don’t really write about this stuff anymore, but one of my first stories in the Daily was about this professor at Stanford who had a theory about multiverses, so it was more about cosmology. I thought that stuff was fascinating. When I first started being a journalist, I would write about anything in science. Now-a-days I’m a little bit more hardcore biology. When I got out of college, my first internship was at Newsweek in NY. They had a really big demand for science stories, but the types of science stories they wanted were not pure science. So I think one of the first stories I did for them was about this diet book, Sugar Busters, because it was the beginning of the whole low-carb thing. So the first thing I did was contribute to a little box, maybe a 600-word box, about the science behind this diet.
What proportion of your stories do you come up with and pitch to your editors?
That’s probably about 75% of the stories that I pitch and 25% that they kind of assign or ask me to do.
Has that changed over the course of your career?
Oh yeah. When I first started at Newsweek, I don’t think they took a pitch of mine for probably the first year that I was there…unless they were really desperate. And being at Nature it also took me a long time to get used to what they wanted. So you feel out your beat, you feel out what your publication wants. So once you figure that out, align your mind with where your audience is, then you do a better job of making successful pitches.
Tell me about your first interview.
I used to prepare a lot more for my interviews. I think now I think about interviewing more as a conversation whereas back then I thought if I didn’t ask kind of the key questions then I was gonna sort of miss the entire story. I think the thing to know about interviewing is that it’s driven by you a lot but it’s also driven to a certain extent by who you’re talking to. They’ll tell you what they want to or are able to tell you at any time, but you can’t trick them into saying stuff they don’t want to say; you can’t get them to reveal things, most of the time, that they don’t want to reveal. So you’ve got to do the best you can and kind of hope that they’re gonna meet you half way.
Have you had any interview disasters?
Absolutely. They happen every single week. Actually, I had one yesterday. But see this is what I mean that if the person you’re talking to doesn’t want to talk to you, there’s not much you can do. I was working on this story about a biotech company that seems to be in some kind of trouble. I’ve been trying to get a hold of the CEO or the COO, and they’re not answering my emails, they’re not answering my phone calls. So finally yesterday I managed to get the cell phone number of the COO, and I called him up. He’s clearly doesn’t want to hear from me, but I still have to ask him all these questions because you can’t write things without giving them a chance to respond. He’s telling me he’s not gonna comment, but I still have to keep asking him questions. It’s my job at that point to get him on the phone as long as I can because maybe he’ll say something. But he didn’t, and finally I just had to say ‘Bye. Thanks for your time.’
But you get comfortable with the idea that sometimes your interview subjects are gonna be antagonistic or they’re not gonna want to talk to you for very good reasons, but you’re just doing your job. It’s hard to talk to people who really don’t want to talk to you, but a lot of times I’m totally astonished by how open people are, especially in the scientific community. One of the coolest things about being a science journalist is the amount of time people are willing to spend talking to you or explaining things to you. They’re excited about their work; they’re excited that you care. The vast majority of times that I’m interviewing somebody, it’s more of a challenge to get them to stop talking than it is to get information. That’s a great thing about being a science journalist.
Is it common for you to be interviewed on the science you report? Are you comfortable with that?
Yeah, that’s happened a few times. It’s becoming more and more common just because everybody has this increasing demand for content, and one way to get it fast is to talk to people who have been doing the reporting. I used to be very uncomfortable with people asking me to play that explainer role because I didn’t feel I was an expert. But I think I’m kind of changing my mind about that. As a journalist, if you can’t do a good job of trying to put your finger on the pulse for someone else, maybe you don’t understand it well enough yourself…
–Jef (Jennifer) Akst
For more information and samples of her writing, visit Erika Check Hayden’s website.
Also, check out some of Hayden’s latest articles:
- HIV: The Next Shot - Nature, July 31, 2008.
- Chemistry: Designer Debacle - Nature, May 15, 2008.
- Stem Cells: The $3 Billion Question - Nature, May 1, 2008.
- Profile: George Church - Nature, Feburary 14, 2008.
- Evolution: Scandal: Sex-starved and Still Surviving - Nature, April 10, 2008.
- The Genome Turns Personal - Discover, December 12, 2007.
- How Africa Learned to Love the Cow - Nature, December 21, 2006.
- The Treasure of Mumbai - Wired, December 2006.
Destined for royalty?
November 3, 2008
We’ve all heard of the nature versus nurture debate: are we a product of our genes or our environment? While the debate raged on for quite some time — with some geneticists arguing feverishly that we are rigid structures constructed according to the precise instructions of our genetic code and some psychologists claiming that who we are depends entirely on how we are raised — scientists soon settled upon the less than satisfying answer that it’s both. Okay, so maybe it is a bit of a cop-out, but it’s true. Who we are and how we develop is an extremely complex process that depends on many aspects of our DNA, our environment, and the interaction between the two.
To make things even more complicated, the genes within your body can interact with each other to generate different traits and behaviors. This phenomenon, known as epistasis, is common and is generally involved in the formation of all of our ‘complex traits,’ like height and skin color. It would be difficult for one gene to generate all the diversity found in such attributes. The story becomes even more interesting when the genes you inherit from your mom interact with those from your dad, such that how you turn out may be a product of how good a match your parents are.
A remarkable example of this ‘genetic compatibility’ was recently documented in a population of harvester ants, Pogonomyrmex rugosus. In this species of ant, one queen mates with many males to produce all of the colony’s offspring. Some of these offspring grow up to be worker ants, while others grow up into young queens that fly off to start a colony of their own. By mating six different queens with males from three different colonies, scientists determined that certain combinations of parents produced a much larger proportion of future queens. However, there were no consistent differences between queens in the percentage of young queens produced. Nor were there any detectable effects of the father’s colony of origin. Thus, the likelihood of developing into a queen depends not on any genetic contribution of either parent, but on how geneticly compatible they are.
So it’s not their mothers who determine their status, like the Nair culture of Southern India. And it’s not their fathers, like the pharaohs of ancient Egypt who would pass the throne on to their eldest son. In these ants, it’s the combination that matters.
Notes:
For more information on the harvest ant story:
Schwander, Tanja and Laurent Keller. 2008. Genetic Compatibility Affects Queen and Worker Caste Determination. Science 322: 552.
For more information on genetic compatibility:
For more information on epistasis, click here.
Are hurricanes growing stronger?
November 2, 2008
Tropical cyclones plague the American coasts each year and are the costliest natural catastrophes in the U.S. With Hurricane Gustav resulting in the largest evacuation in Louisiana’s history and Hurricane Ike costing an estimated $30 billion in damage, this storm season once again begs the question: are tropical storms growing in intensity? Read more…
