Last week on my balcony, I saw an albino cricket. Well, actually, it wasn’t specifically albino, since it didn’t have pink eyes – it was more of a light beige color. The twist? It’s color exactly matched the exterior color of my apartment building, which was painted about five years ago. I’ve also seen a snail and a baby spider which are exactly the same color, and I’ve never seen this color on a cricket anywhere else. Is this proof of evolution in action?
Incidentally, I tried to tell this story to my Creationist Mom, but she just poo-pooed the idea, and instead read to me this mass email which apparently she has taped to the side of her computer. :rolleyes: So, what about the crickets? Will somebody please think of the crickets??
Without being an expert on insects I can tell you that mutations happen in nature all the time and while it may appear that this apparent beneficial mutation may give this particular cricket some advantage versus a “normal” colored cricket I dont think that means that crickets are evolving in one particular direction or another.
What would happen if I took that same cricket and placed him on the side of a dark colored building? His new coloring would now be quite deliterious.
If you found a population of light colored crickets then that might mean some local adapation… but it’s more likely a happy accident of genetics you happen to notice. Are you sure crickets can’t change their color to some extent to blend in with their surroundings?
It’s very unlikely. The area concerned (one house) is too small and the time scale (five years) too short. Evolution is something that happens in populations. The population of crickets at your house is no doubt not separate from those of neighboring houses - crickets move between them regularly - so that the selective regime at your house alone would not be enough to cause change in the effective population. Also, selection would have to be pretty intense to cause any real change in the span of five years, even for something that breeds as rapidly as a cricket.
However, in the case of more isolated populations, or in the face of intense selection, an adaptive change of the kind you describe is not out of the question. In fact, such small changes, know as microevolution, are so well documented that many creationists admit that they occur. Creationists, however, generally deny that such microevolutionary changes will eventually result in speciation, or what they consider “real” evolution.
In any case, if your Mom’s a Creationist, it’s unlikely she will be convinced by either evidence or logic.
That probably wasn’t an albino. It’s fairly hard to get albino forms of insects because the pigmentation process is a lot more complex than im mammals. A lot of the dark pigments are actually waste products that are shunted into the new skin after a moult to get them out of the body and make the animal taste bad. Even ‘albino’ animals produce those wastes, so they end up dark anyway.
Most likely what you saw was a freshly moulted cricket. A lot of the orthopterans are pale or even white when they first moult. Then as the new skin develops it has the pigments added and the colour darkens over several hours. That’s why there are so many ‘albino’ cockroaches seen. They are in fact normal conckraoches with a new coat. I’m guessing this cricket was the same, unless you’ve seen it for several days.
Maybe they were painted!! It’s possible that the grounds keeper recently painted an area of the apartment that was filthy or something. This spider and this cricket may have caught some of the spray. That would explain the exact color match, anyway.
This brings to mind the story of the Peppered Moth, taught to me as fact in High School biology in the early 80’s, but now under significant scrutiny. Nonetheless, the very real phenomena of antibiotic-resistant germs demonstrates natural selection well enough for me.
There’s a more recent case (which, alas, I can’t give you a cite for) of a similar case. A moth in the NE US was generally pigmented to nicely match the gray bark of the pines of the area. Every species has “sports,” variations from the usual coloring. Gradually, as acid rain turned the pine bark darker, the darker sports survived to reproduce, and the gray moths became the sports.
Since crickets have green blood, the eyes would be greenish. Beside which, ain’t albinos not so much which as colorless/pigmentless? :o