Lose Sense of Smell, Live Longer
A whiff of greasy pizza or the scent of a fresh salad may directly alter how long you live. Scientists have long known that specific odors can alter an animal’s lifespan – when the sense of smell was removed from nematodes and fruit flies, they lived far longer than their “Smeller” brethren. The only question was: how was the sense of smell able to affect the longevity so distinctly?
Molecular biologist, Scott Pletcher, and his team decided to find out. Using a group of fruit flies as test subjects, they removed the flies’ ability to smell CO2, a scent indicative of their main food source, yeast. When the ability to smell CO2 was removed from a fruit flies olfactory system, female fruit flies lived 30 percent longer than the males. Pletcher believes the sensory switchup had no effect on the males because females are just more sensitive to CO2.
Pletcher believes that the inability to smell CO2, and thus the inability to track down food sources, put the female flies into survival mode. Specifically, female fruit flies in survival mode store extra fat and became more resistant to oxidative stress – both things that directly increased the female flies’ chances of living longer than males.
Only specific smells trigger this survivalist response; in flies, it’s CO2, but in humans it may be something completely different, or may not exist at all. “We definitely undergo physiological changes in response to smelling food,” explains Matt Kaeberlein, who studies aging at the University of Washington in Seattle. “I’m getting hungry just thinking about it – so I think it’s possible.”
On a similar note, our very own Landslide has no sense of smell and will therefore likely outlive everyone else at The Escapist HQ.
Source: New Scientist
Human Ancestors Bred With the GEICO Cavemen
A new study of the genes of nearly 2000 people shows that our ancestors may have interbred with other species of humans, possibly with the likes of our favorite GEICO Neanderthal cavemen.
“It means Neanderthals didn’t completely disappear,” states Jeffrey Long, a genetic anthropologist at the University of New Mexico. “There is a little bit of Neanderthal leftover in almost all humans.” It was previously believed that Neanderthals and the Homo genus had never interbred, and that the Neanderthal line had died out while the modern human line flourished.
Scientists tracked over 600 microsatellites, which are like genetic fingerprints, in 1,983 individuals in 99 distinct populations in Africa, Europe, Asia, Oceania and the Americas. Doctoral student, Sarah Joyce, used the results to create an odd genetic tree that could only be explained if ancient humans had mated with other humans species, such as Homo neanderthalensis and Homo heidelbergensis. Using SCIENCE! (and statistical projections), researchers found that ancient humans likely bred with archaic species two different times, once about 60,000 years in the Mediterranean, and again in eastern Asia about 45,000 years ago. Both events occurred after the first Homo sapiens had migrated out of Africa.
Their findings were announced at the American Association of Physical Anthropologists, and attending researchers agreed that such interbreeding would explain variations found in the human genome. “This information is really helpful,” states Linda Vigilant, an anthropologist at the Planck Institute. “And it’s cool.” Well said, Vigilant.
Could this explain the recent finding of Woman X , the latest fossil of a human whose mitochondrial DNA shows that she canoodled with both Neanderthals and modern human species?
Source: New Scientist
Brother Sperm Help Each Other Out
Science used to believe that sperms mindlessly raced towards a singular destination, with the sole mantra of “PENETRATE EGG” guiding their swim. However, we’ve found that they can battle against one another, take a breather, and now – even help each other out. Related sperm can identify each other and “draft,” setting up a semen train a la Lance Armstrong, getting in line in order to reduce the overall drag.
“It’s really amazing that this single cell can do this,” states Heidi Fisher, evolutionary geneticist at Harvard University. “We used to think of sperm as packs of DNA with really fast tails. But [now we know] they’re able to make these complex organizations.”
The discovery was made by Fisher and colleague, Hopi Hoekstra, who took sperm from mice, put it in a dish, and watched what happened. The sperm were identified by a special dye which glowed under UV light. The sperm of one mouse glowed green, the other red.
Two experiments were performed: one using sperm from unrelated mice and one using sperm from related males. In both tests, the sperm grouped up. When both sets of sperm were unrelated, they grouped up randomly. But when the sperm was from a related male, they tended to cluster more often with their genetically-related sperm than a stranger’s sperm. Even odder: once the sperm reached the egg, the competition was back on and brother sperm became rivals once again.
Source: National Geographic
Whale Poop: Solution to Global Climate Change?
There have been some pretty silly suggestions on how we, as a whole, can help stop global warming. However, I think this one takes the cake: stop global warming by letting whales poop. It’s exactly as silly as it sounds, but I think it might have some merit.
Here’s the basic set-up: Whale feces has a lot of iron in it. Phytoplankton feed on iron. Phytoplankton absorb carbon dioxide. Phytoplankton is eaten by krill. Krill is eaten by whales. It’s a neat little cycle. The problem is, due to commercial whaling pressures, whale populations have been slowly dying out. According to Stephen Nikol, of the Australian Antarctic Division, just baleen whales may have been the source of nearly 12 percent of all iron within the Southern Ocean. That’s only baleen whales, folks.
Scientists have long known that iron is an effective way to counter global warming. However, suggestions to introduce soluble iron into the ocean were met by criticism and concern by environmentalists. How much iron is too much? How would the ocean react to such an abrupt change in chemistry? The answer lies in whales.
“Allowing the great whales to recover will allow the system to slowly reset itself,” states Nicol.
Lauren Admire says “Remember, kids: Science explains miracles!“