1. clock
  2. Both Male-Male Competition and Mate Choice are parts of Sexual Selection

Both Male-Male Competition and Mate Choice are parts of Sexual Selection

By clock on December 18, 2008.

Beaked Whales' Tusks Evolved Through Sexual Selection Process:

For years, scientists have wondered why only males of the rarely seen family of beaked whales have "tusks," since they are squid-eaters and in many of the species, these elaborately modified teeth seem to actually interfere with feeding. A newly published study help explain the evolutionary origin of these distinctive "tusks" in beaked whales, a rather mysterious family of whales that live in the deep oceans. Although the tusks are known to be used in competition between males, another purpose seems to be to attract female beaked whales - and to avoid mistakes in choosing a mate.

Hmmm, I have read Darwin's "Descent of Man" and the take-home message from it was that, if there is a big difference in a trait between males and females, then sexual selection is the first, default hypothesis. Why should this one be a 'surprise'?

I think they mangled their terms - both 'male-male competition' and 'female choice' (or 'male choice' in some species) are aspects of sexual selection. What they were trying to say is not that the sexual selection hypothesis is new for tusked whales, but that they discovered that the tusks are also a part of 'mate choice', and not only 'male-male competition'. Nice finding, but not that surprising.

Tags
evolution

More like this

Can sexual selection account for giraffe necks?
A giraffe, photographed at the Bronx zoo. Why do giraffes have long necks? We know that modern giraffes must have evolved gradually, but figuring out what selection pressures influenced giraffe evolution is another story altogether. One of the most popular recent explanations is that giraffes…
Let's talk about...Sexual Selection
Update: Greg Laden has a post worth reading on tis topic. Sexual selection is an expansive topic. It is also one with a complicated history and fits messily into a rigorous empirical research program. I will base this post predominantly on the verbal exposition in R.A. Fisher's The Genetical…
Topi or not Topi ...
Go to any bar and you'll see a lot of males standing and sitting around not mating. I'll bet you would have guessed that the reason they are not mating is that no females will mate with them for one reason or another. But there is the distinct possibility that they are very inconspicuously…
Topi or not Topi ...
Go to any bar and you'll see a lot of males standing and sitting around not mating. I'll bet you would have guessed that the reason they are not mating is that no females will mate with them for one reason or another. But there is the distinct possibility that they are very inconspicuously…