It’s time to go spanning the globe for anatomy news and notes:
Mosquitoes & Us
Barbecue season seems like a good time as any to contemplate what attract mosquitoes to us humans. And why some of us get eaten alive while the next person seems immune and goes home scratch-free. The good news is scientists are still working on figuring out the best defense.
Some people are “mosquito magnets,” says Dr. Conor McMeniman, an assistant professor of molecular microbiology and immunology at the Johns Hopkins Bloomberg School of Public Health and Johns Hopkins Malaria Research Institute in Baltimore. (The full article is here from the WSILTV website).
Some of us are tastier. It’s chemistry. It might be your diet, genetics, or basic physiology. Each of us has a unique “odor bouquet.” Work is ongoing but, says McMeniman, there is a “general pattern” that suggests one of the most important scents is from carbon dioxide, the gas we exhale when we breathe.
What to do? There’s no magic fix. Scientists say gadgets don’t work. And some insecticides are dangerous to both the environment and possibly the guests munching hot dogs at your backyard soiree.
So, cover up. Consider a natural botanical such as lemon eucalyptus. And hope the scientists figure this out soon!
Handy Proof of Evolution
We love this quick, well-produced video from Vox Observatory that demonstrates ready evidence of human evolution. If you’re a teacher, you might find these observations useful.
Did you know the Palmaris longus is missing in about 10 to 15 percent of people? That it can be missing on one or both arms? If you lay your arm on a flat surface and push your thumb and pinky together, while tipping your hand slightly up, you should see the vestigial muscle in your forearm. (Or not.).
What’s interesting is that even if you don’t have a Palmaris longus you aren’t any less strong. If you’re missing one, your grip strength isn’t any less. Palmaris longus muscles are found across mammal species, but it's most developed among use their forelimbs to move around. In other words, brachiators. So Palmaris longus is longer in lemurs and monkeys, and shorter in chimps, gorillas and other apes that don’t swing (across treetops) as much. In us humans, it’s just a leftover muscle—but clear evidence of our roots.
It's a great video that also demonstrates other leftovers in our bodies today—muscles around the outer ear, for instance, and goosebumps, too. Check it out!
That’s Early Corn!
Let’s go to Honduras and check in on the work at El Gigante, a rock shelter that’s one of the few archaeological sites in this hemisphere that contains well-preserved botanical remains going back 11,000 years. (El Gigante has been nominated as a UNESCO World Heritage site.)
Now, anthropologists Douglas Kennet and Amber VanDerwarker from University of California Santa Barbara and other researchers from multiple institutions have excavated and analyzed botanical macrofossils — such as maize cobs, avocado seeds or rinds —using modern technologies. And they’ve discovered early use and management of tree crops such as wild avocado and plums. Yes, 11,000 years ago. The details were published by EurekaAlert! here.
The evidence adds to understanding of tree and field crop use. Tree fruits and squash were being consumed 11,000 years ago, maize around 4,500 years ago, and beans around 2,200 years ago.
“Forest management and arboriculture persisted for thousands of years before it was eclipsed in importance by the expansion of maize farming after 4,000 years ago,” said Kennet in the EurekaAlert article. The archaeological record provides an archive of human adaptation that should be considered in the context of anthropogenic alteration of our Earth’s climate today. These ancient archives could help rural farmers in Central America adapt to changing conditions moving into the future.”
Reminds us of barbecue season. And, once again, mosquitoes. Wonder if the scientists know whether the folks were swatting at bugs way back when at El Gigante?