Posted on 04/01/2014 2:24:42 PM PDT by bkopto
Zebras have evolved white and black stripes as camouflage to confuse lions. That's the conventional wisdom, anyway. But, as is so often the case, the conventional wisdom appears to be wrong.
New research in Nature Communications concludes that zebras' stripes are actually for preventing bites from nasty insects, such as tabanids (horse flies). For some reason, these flies avoid landing on black and white striped surfaces.
For their study, the authors collected stripe pattern data on seven wild equids: plains zebra, Grévy's zebra, mountain zebra, African wild ass, Przewalski's horse, kiang, and Asiatic wild ass. They then overlaid a map of these equids' ranges with information on predators' ranges, temperature, biomes, tsetse fly ranges, and tabanid ranges (which were determined by proxy using measurements on temperature and humidity). They found that the presence of equid stripes most closely correlated with the ranges of biting flies, such as tabanids and tsetse flies. In other words, equids are more likely to have stripes if they live in an area that also has biting flies.
Simultaneously, the authors' map mostly eliminated the other possible explanations that exist for zebra stripes: camouflage, predator confusion, body temperature control, and social identification. However, the presence of rump and leg stripes correlated with the range of hyenas, so it is possible that the stripes play a role in keeping hyenas at bay. The authors argue, though, that adult zebras are generally too big and powerful for hyenas to hunt, so it is unlikely that striping patterns play an important role here. Also, Asian equids that were once hunted by wolves and tigers do not have stripes.
Thus, the evidence from this and previous studies indicates that zebras have stripes to avoid flies, not lions.
(Excerpt) Read more at realclearscience.com ...
It's actually a lavender animal with black AND white stripes covering up the lavender completely.
Well, that's my theory. Nobel Prize here I come!
Joe, you are ALWAYS on top of the current events, and ALWAYS a step ahead of whoever is in second place! LOL!
If they bit zebras, they would be called zebra flies. How obvious can it be?
LOL!
Oh my!
Well. That’s rather stilted and arcane...
Maybe this is evidence that natural selection doesn't work.......at least not in fly populations.
......and that's the problem with so much of Darwinian thinking: Natural selection is believed with certainty to explain all things, so contrarian thinking is not even imaginable to the majority of our evolutionary biologists.
Yep.
Why didn’t the other mammals evolve stripes?
I'm going with the lion theory. Think about it for a minute.
If your stripes keep the flies away that has no impact whatsoever on your survivability. If your stripes confuse lions WHO WILL KILL YOU it has a huge impact.
It’s not dumb luck, it’s natural selection. The language used is just a way to describe the factors that lead to the adaptation. Nobody is trying to imply intent.
That's a fair question, but it's a stretch to think that an answer would show natural selection doesn't work.
I'll point out that this theory that the stripes deter flies wasn't actually tested. They showed a correlation between populations and inferred that the flies didn't like stripes. That should then be tested. The prediction is these flies would avoid stripes. So you get some flies and set up an experiment to find out. This could be wrong, despite the correlation.
Yup. A couple of conspiring evil doers bent on doing evil.
That’s very true.
The way I was taught it in high school with the implication of some intent by nature. An example would be that birds developed hard beaks in order to crack open the hard shells that contained nuts. The above sentence implies some intelligence by the bird.
But it’s just the language used to explain the driving factor. Intent is not actually meant.
But how well would evolution fly in grade school when you tell them that the reason animals evolve is because of random events and that dinosaurs turned into birds because of random factors and it is just luck that they survived up to this very day.
There are two difference concepts involved in evolution. Variation, which is random. And natural selection, which is not.
Random variation is only the raw material used by the process of natural selection. Evolution is not random dumb luck. It is the environment of the organism shaping the biology over the generations. The process must have variations to choose from, and those variations come from random events, but the process is not random.
Wouldn’t this adaptation benefit every animal trying to avoid flies and other biting insects?
...African Wild Ass...Those African Wild Asses are dangerous:
One is running around Chicongo in a beat up White Crown Vic that the coppers are looking for. He shot two people yesterday in a span of a couple hours, one of whom died on scene, the other in critical condition with a bullet in his brain. And when the Cops find him he's gonna wish he had Black & White stripes as he's gonna get ventilated given the chance.So if you ever come upon these African Wild Asses be very aware, those asses are very unpredictable.And this past Saturday about 100 African Wild Asses had a nice little riot, aka 'Wilding', where the Rich Folk live, Shop & Party -- 'The Mag Mile', and right in the middle of the street at Chicago Avenue & Michigan Ave. But 'somehow' Chicongo's crack media missed reporting on this event, I found out through a police source.
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