Science column: Knowledge bites
Published: Monday, October 7, 2013
Updated: Monday, October 7, 2013 23:10
I've had a couple of little interesting things catch my fancy lately, but none of them seemed complicated enough to warrant an entire post. Therefore, I've decided to compile them into something called “knowledge bites” (in keeping with our dinner table theme) and just throw them all at you at once. Enjoy!
Mosquitoes and Rainfall
I know that we always correlate high mosquito numbers with high rainfall because “mosquitoes like standing water.” While this is true, in a way, the real correlation between climate and mosquito numbers just blew my mind the other day. During the summer, most mosquitoes lay their eggs near standing water, right at the surface of it or on moist soil. Mosquito larva need water to live in (they're like little swimming bugs before they turn into adult mosquitoes) so the next year, the eggs hatch when the water level rises and warms up and “activates” them. This means that during a year with a lot of rainfall, the water level gets higher than normal and all of the mosquito eggs (even ones laid years ago that haven't hatched because the water hasn't been that high in a while) hatch and we have a lot of mosquitoes. However, mosquitoes don't live very long, and soon enough they'll all die and their eggs, which were laid when the water was unusually high, won't hatch for a while, so we'll probably have some period of low mosquito populations.
Fingerprints for All!
Our fingerprints are unique—no one person in the world has prints the same as yours. That's amazing, and it also really helpful in fields like law enforcement and criminal justice. However, this idea of a unique physical marker is not restricted to just humans. For example, a dog’s nose print is unique to each individual and can be used to identify them. The same goes for zebra stripe patterns and cheetah spot patterns; really any patterned animal is unique. Cows, like dogs, have unique nose prints as well. Some primates (like chimpanzees and gorillas) and even non-primates (like koala bears) have fingerprints just like humans do.
Even though science has made great strides, even in the last few years, we're far from understanding everything about the world around us. More surprisingly, we're pretty far from understanding our own bodies. Scientists still don't know why we yawn, or why we blush or why we dream. The best explanation out there for why we need to sleep is “we get sleepy.” Scientists also don't have a good handle on why the placebo effect works. For a quick refresher, a placebo is a pill, usually used during statistical testing, that has no drugs and serves no purpose. However, if you tell someone that it cures something—like headaches for example—many times, they will report decreased headaches and claim the drug works. Doctors have even conducted fake surgeries on people and had them be equally as effective as the real thing! Certainly there are times when an ailment is all in our heads and a placebo would do the trick, but scientists suspect that the mind is capable of healing actual physical illnesses when put to the test, and that's what backs up the placebo effect; it's just that no one has proven this yet.