A few weeks ago a college friend of mine (and geneticist) alerted me to a PLoS Biology commentary by bacterial geneticist Rosemary Redfield (of arsenic life fame) entitled “Why do we have to learn this stuff?” – A new genetics for 21st Century Students. I’m not a geneticist, but to my eyes this piece is both refreshing and thought-provoking and definitely worth a read for any science professor or aspiring professor.
Microscope image of mitochondria in mammalian lung tissue. (Photo: Louisa Howard)
A person’s genome is a unique combination of genes inherited from both his or her mother and father (with some random mutations thrown in). But each person also inherits another type of DNA — mitochondrial DNA (mtDNA). Mitochondria, the bacteria-like organelles that provide power for our cells, contain their own genomes. An individual’s mtDNA is almost identical to that of his or her mother’s mtDNA because those mitochondria are direct descendants of the mitochondria in the fertilized egg cell (the sperm’s mitochondria are usually chewed up by the egg). In fact, we can take advantage of this to track how groups of people are genetically related and to trace our own ancestry. But the fact that mtDNA is only inherited from our mothers produces an interesting evolutionary phenomenon: some mutations in mtDNA are harmful only to male offspring and not to female offspring. A recent paper by M. Florencia Camus, David Clancy, and Damian Dowling published in Current Biology examines how this “Mother’s Curse” may lead to shorter lifespans in male flies.
Does the science support a ban on female athletes with high testosterone levels?- AAAS MemberCentral post
Caster Semenya, left, during the 2011 World championships Athletics in Daegu, South Korea. (Photo: Erik van Leeuwen (bron: Wikipedia))
In time for the London 2012 Olympic games, the International Olympic Committee (IOC) released new guidelines for determining whether female athletes with high testosterone levels are allowed to compete in the games. A female athlete may be ineligible due to a testosterone level within the normal male range because this “confers a competitive advantage” to her. A recent paper in the American Journal of Bioethics lambasts these new guidelines (as well as those by the International Association of Athletic Federations, IAAF) and highlights how they are not based on scientific evidence.
Aging animals, including honeybees, often show signs of cognitive decline such as poor memory and problems with learning new information. We know that aging impacts behavior, but can behavior also change how the brain ages? A recent study by Nicholas Baker, Florian Wolschin, and Gro Amdam published in Experimental Gerontology explores an interesting connection between age-related learning deficits and behavioral roles in honeybees.
Photo: George Joch/Argonne National Laboratory
Could stereotypes be partially to blame for the relative dearth of women in high level jobs in engineering, computer science, and other STEM fields? Recently on NPR’s “All Things Considered” Shankar Vedantam discussed evidence of “stereotype threat” in a study that examined recorded conversations between male and female scientists. I had never heard of stereotype threat before and so this study piqued my interest.
“Harmony before Matrimony” by James Gillray
Oxytocin (or the ‘love hormone’ as it’s often called) is an important regulator of sexual arousal, pair bonding, and maternal behavior. Oxytocin also regulates non-reproductive social behaviors, which can be artificially manipulated by changing oxytocin levels. When people playing investment games in a research setting inhaled oxytocin, they became both more trusting and more empathetic towards other players. But can too much oxytocin be a bad thing?
One of the graphs included in the report, showing the growth in the number of biomedical Ph.D.s (Image: NSF Survey of Earned Doctorates)
The NIH’s Biomedical Research Task Force recently released a report that includes recommendations for how to change graduate and postdoctoral training in order to “support a future sustainable biomedical infrastructure.” As a current postdoc living in the biomedical career trenches, I found this report fascinating and a lot of food for thought.
Decidedly ‘unhelpful’ cholera bacteria (Photo: T.J. Kirn, M.J. Lafferty, C.M.P Sandoe and R.K. Taylor, from http://www.cellimagelibrary.org/images/40396)
While most people think bacteria only make us sick, some bacteria actually helps the human body preform important jobs. And, a new study shows that bacteria can strengthen our immune systems and get us ready to fight more dangerous infections.
Read more of my AAAS MemberCentral post here.