Scientists Breed Big-Brained Guppies To Demonstrate Evolution's Trade-Offs

An anonymous reader writes "Scientists have long suspected that big brains come with an evolutionary price — but now they've published the first experimental evidence to support that suspicion, based on their efforts to breed big-brained fish. A Swedish team found it relatively easy to select and interbreed common guppies to produce bigger (or smaller) brains — as much as 9.3 percent bigger, to be precise (abstract). But the bigger-brained fish also tended to have smaller guts and produce fewer babies."

Breed for one trait, other traits deteriorate.

[erice]

This doesn't seem very enlightening. If small guts are normally selected against and you specifically breed them, providing they also have large brains, it should come as no surprise that your large brained guppies have smaller guts on average. If all the large brained guppies have smaller guts then brain size and gut size are probably controlled by the same genes: in guppies. That's interesting but not very general.

I would be more interested to see if they could genetically engineer guppies with large brains and normal size guts and see if they are competitive with their unenhanced cousins. Alternatively, but less conclusively, they could attempt to breed large brained guppies with normal sized guts. A negative result would suggest that either this combination of traits either can not be encoded or does not survive if encoded. How well understood is the guppy genome?

Re:Has nothing to do with evolution

[WillgasM]

Who said evolution had to be natural? Did one breed of dog not evolve into several others through selective breeding? Evolution is a result; natural selection, selective breeding, etc are a means to that end. I have to agree (at least I'm assuming we agree) that this doesn't necessarily prove much. When working with a limited gene pool and a short amount of time, you won't necessarily mimic the results of eons of natural selection. Maybe their big brained guppies had a dominant gene for small guts and low libido, but that doesn't mean the guppy population as whole shares these traits. Also, with enough time, you could have all sorts of genetic variations that could potentially result in fat, horny, big-brained guppies. I'm not saying their research is patently flawed, just that it may or may not reflect trends in the real world. It's kinda impossible to know for sure without a spare universe and infinite amounts of time.

Re:Has nothing to do with evolution

[aardvarkjoe]

Not evolution

Obviously this is intelligent design.