2010 Stories
Evolving altitude aptitude
If you live in the lowlands, you may have experienced the huffing and puffing that typically accompany a trip to higher altitudes. That’s because oxygen levels go down as one goes up. Travelling to Denver from sea level means a 17% decrease in available oxygen. Our bodies compensate for even this small change with faster breathing and a higher heart rate — at least until we acclimate to the thinner atmosphere. And a loftier vacation spot (for example, La Paz, Bolivia at 11,942 feet) could bring on serious altitude sickness with insomnia, nausea, and swelling — but not for everyone. Tibetan highlanders have no trouble living at 13,000 feet year in year out, and many Nepalese Sherpas (who are ethnically Tibetan) climb parts of Mount Everest without the supplementary oxygen most people require. How do they do it? New research makes it clear that Tibetan highlanders haven’t just acclimated to their mountain home; they’ve evolved unique physiological mechanisms for dealing with low oxygen levels.
Read more »Genetic variation helps rescue endangered panthers
This fall, biologists announced the apparent success of a last-ditch conservation effort: the Florida panther, once slated for extinction, has been given a second lease on life by the infusion of genetic variation. In the 1900s, this population nosedived because of hunting and habitat loss. By the 1990s, there were fewer than 30 Florida panthers left. To make matters worse, those survivors were in bad physical shape. They were riddled with diseases and parasites and had poor sperm quality and low fecundity, as well as a host of problems like undescended testicles, kinked tails, and heart defects. Scientists predicted that the Florida panther would be extinct within 20 years and, in 1995, formulated a bold plan to save them.
Read more »Spreading disease on evolutionary timescales
If you are trying to stay healthy this cold and flu season, you may find yourself washing your hands frequently and avoiding crowded places like schools and airports. That’s because most infectious diseases that we are familiar with are passed from human to human — and the more human germs you come into contact with, the more likely you are to have one make its home in your body. However, on evolutionary timescales, pathogens don’t necessarily respect species boundaries. Biologists have discovered more and more cases in which diseases have passed from another species to humans. And, as you might expect, the more closely related the other species are to us, the easier it seems to be for the pathogen to make this jump. The most recently discovered case of disease swapping among species involves the deadliest strain of malaria, Plasmodium falciparum, which causes more than a million deaths each year.
Read more »Bed bugs bite back thanks to evolution
Bed bugs might sound like an old-fashioned problem, but now they are back — and with a vengeance. Fifty years ago, the blood-sucking pests were nearly eradicated in the United States thanks in part to the use of pesticides like DDT. Today, they are creeping over sheets — and tormenting hapless sleepers — across the country. New York was recently declared America’s most bed-bug-infested city: Times Square movie theatre, the Empire State Building, and the offices of a major fashion magazine — not to mention the homes of 11,000 New Yorkers who filed official complaints about the vermin last year — have all housed these itchiest of bedfellows. And the Big Apple is not alone in its disturbed slumber. This summer, the Centers for Disease Control and Prevention (CDC) and the Environmental Protection Agency (EPA) issued a joint statement on the resurgence of bed bugs throughout the country. Wherever you live — whether that’s Los Angeles or Louisville — bed bugs may soon be coming to a mattress near you
Read more »Las chinches de cama pican de nuevo gracias a la evolución
Las chinches de cama puede parecer un viejo problema pasado de moda, sin embargo ahora están de vuelta — y con venganza. Hace cincuenta años, estas plagas chupadoras de sangre estaban casi erradicadas en los Estados Unidos gracias, en parte, al uso de pesticidas como el DDT. Hoy, se arrastran entre las sabanas — y atormentan a los desgraciados soñadores — en todo el país. Nueva York, fue recientemente declarada la ciudad con mayor infestación de chinches de cama en Estados Unidos: el cine de Times Square, el edificio del Empire State, y las oficinas de una importante revista de moda — sin mencionar las casas de los 11.000 neoyorquinos que presentaron quejas oficiales por esta plaga el último año — han alojado a estos irritantes compañeros de cama. Y la Gran Manzana no está sola en su sueño perturbado. Este verano, el Centro para Control y Prevención de Enfermedades (CDC) y la Agencia de Protección Ambiental (EPA) emitieron una declaración conjunta sobre el resurgimiento de las chinches de cama en todo el país. Dondequiera que usted viva — ya sea en Los Ángeles o en Louisville — las chinches de cama podrían estar llegando pronto a un colchón cercano al suyo!
Read more »Making sense of ancient hominin DNA
In October 2022, Svante Pääbo was awarded the Nobel Prize in Physiology or Medicine for the work described below.
In the last two months, news outlets have been abuzz with the announcement of what many suggested was a new hominin species. In 2008, a 40,000 year old pinky bone from a child was discovered in a Siberian cave. The bone was not enough to identify the species of its possessor, but since both Neanderthals and humans are known to have lived in the area at the time, scientists assumed it belonged to one of these two species. That all changed in March of this year, when German researchers announced that they’d managed to extract DNA from the fossil — and it didn’t match up to the known genetic sequences of either humans or Neanderthals! In fact, the human and Neanderthal sequences were more similar to each other than either was to the fossil’s sequence! Could this finger bone represent a newly discovered species — nicknamed X-woman? Is the human family tree even bushier than we’d previously thought? Many news outlets touted this research as the first case in which a new species was discovered on the basis of DNA alone. Here, we’ll examine the evidence in more detail and consider what that evidence might — or might not — mean about such claims.
Read more »One small fossil, one giant step for polar bear evolution
As the fuzzy and ferocious poster child for climate change issues, polar bears get plenty of press, whether it’s coverage of something as simple as the birth of a cub at a zoo or as political as a rejected ban on trading polar bear parts. Last month, however, saw a polar bear story of a different ilk — a story about the bears’ evolutionary past that has implications for their evolutionary future. Polar bears, it turns out, may have evolved surprisingly quickly in response to past climactic changes. Here, we’ll examine the different lines of evidence that led scientists to this conclusion.
Read more »The evolutionary history of jogging
If you are health conscious or have been in a sporting goods store lately, you might have heard about a new fitness trend: barefoot running. Enthusiasts hit the pavement (or the grass, or the track) sans shoes entirely or with minimal foot protection — and the trend is catching on. Clubs dedicated to barefoot running have sprung up, devotees crash marathons to run barefoot, and shoe companies are jumping on the bandwagon with shoes that mimic the effect of running barefoot — including some that look like rubber gloves for your feet. Barefoot running may sound like just another fitness fad, soon to go the way of hula-hoops or jazzercise, but this trend has a surprising connection to evolution.
Read more »Speciation in real time
We often think of speciation as a slow process. All the available evidence supports the idea that different species evolved from common ancestors, and yet, new species don’t pop up around us on a daily basis. For many biologists, this implies that speciation happens so slowly that it’s hard to observe on human timescales — that we’d need to track a population for millennia or more to actually see it split into two separate species. However, new research suggests that speciation may be easier to observe than we thought. We just need to know where to look.
Read more »Especiación en tiempo real
Generalmente, pensamos en la especiación como un proceso lento. Toda la evidencia disponible sostiene la idea de que diferentes especies evolucionaron desde ancestros comunes, y sin embargo, nuevas especies no aparecen a nuestro alrededor diariamente. Para muchos biólogos, esto implica que la especiación ocurre tan lentamente que es difícil observarla en escalas de tiempo humanas — y que necesitaríamos seguir una población por milenios o mas para verdaderamente ver como una especie se separa en dos. Sin embargo, nuevas investigaciones sugieren que la especiación podría ser más fácil de observar de lo que pensamos. Simplemente, necesitamos saber donde mirar.
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