Cockroaches Evolving To Avoid Roach Motels

sciencehabit writes "Only a few years after roach motels were introduced in the 1980s, they lost their allure for an increasing number of German cockroaches. Researchers soon realized that some roaches had developed an aversion to glucose—the sugary bait disguising the poison—and that the insects were passing that trait on to their young. Now, scientists have figured out how this behavior evolved."

Comments

Easy fix to this problem

[volkerdi]

Use high fructose corn syrup in the roach motels instead of glucose. I'm surprised they don't do this already, since they use it in everything else.

Re:Is it evolution, or survival of the fittest?

[Black Parrot]

Seriously, did the roaches actually evolve and pass it to their young, or did the specific roaches which HAD the sugar aversion trait simply avoid being poisoned and passed along said aversion to their offspring?

I'm kinda thinking it's the latter.

I'm kinda thinking that's evolution.

Re:Ah, yes!

[sqrt(2)]

There's really no distinction. What is called macro evolution is determined by hindsight, usually because we are only able to compare fossils separated by millions of years. By definition every organism is a member of the same species as its parents. We only place them into discrete categories for taxonomical convenience. It's not a fact of nature, it's a human contrivance to make doing (some aspects) of biology easier.

It's like natural languages. I speak English, a Germanic language. I can speak to my father and mother just fine. I can speak to my grandfather, and also converse in German with him. If my great-grandfather were still alive I'd doubtless have no trouble speaking to him, too. He could speak to his parents. They could speak to their parents, and so on. Each person in the chain can speak to and understand the people directly around them. But if you go back just a few hundred years, I wouldn't be able to easily converse with my ancestors, despite the fact that there is an unbroken chain connecting them to myself linguistically. Farther back and I wouldn't even recognize the language they're speaking as English, or German. So from microevolution comes macroevolution of languages.

So to with biology. If we had access to a fossil or living specimen of every intermediary individual from single cell to human then the very idea of species would become meaningless, lost in the smooth gradient of gradual change. You could line them all up and walk down the line and see them change, almost imperceptibly from one form into another. Every individual would look so much like his parents and offspring that you wouldn't even be able to tell there was a change at all. But you could compare every 10, 100, or 1000 individuals and see that they are in fact changing. At some point they'd be so different as to need a new name, for humans have an almost pernicious compulsion to place things into discrete categories.

Some people find it impossible to break out of this mindset. Some find that their religion even compels them not to try.

Re:Ah, yes!

[sqrt(2)]

Mutations are random, and most aren't improvements, aren't adaptive. Natural selection then goes to work. The mutations which are better become more numerous by virtue of being better. Detrimental changes terminate the organism's lineage by killing it outright or making it less successful at reproducing. Drop a bacterium into a pond and after a billion years I'd expect to still find bacteria or something analogous in that pond. Ignore the fact that location on the Earth loses meaning at that time scale due to plate tectonics. I'd expect to find bacteria AND lots of other forms of life all over the place everywhere I looked. This demonstrates another misunderstanding ID people have with evolution. Bacteria and humans are equally evolved. We've all been evolving for the same amount of time. Bacteria are just as old as humans, all contemporary species are. No extant species is "less evolved" than any other. You can say they are "more primitive" but what does that really mean? Compared to what?

Anthropocentrism is a vice biologists are broken of early on. Religious people often find the idea that humans aren't special, that the world wasn't made just for us, positively abhorrent. Strangely these same religions often preach humility. What a contradiction.