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Marsdreamer t1_j9i2pi4 wrote

Not always. There's a great example of an evolutionary study on a bird species that had incredibly long tails. Like, tails that were so long that they often interfered with flight and made the bird significantly more likely to be caught by predators.

However, the females preferred males with longer tails. So, what essentially happened is that the male birds continued to grow their tails as long as they possibly could until they hit a sort of critical threshold of being maximally attractive for females, but juuuust short enough that it didn't completely hinder their ability to get away from predators and fly.

Researches assayed this by taking feathers and artificially elongating certain male bird's tails (basically bird hair extensions). They noted that these doctored birds had significantly higher mating rates than other birds, but on the flip side, they also got caught (and killed) by predators much more often.

There's tons of examples of this throughout nature, where sexual selection essentially overrides the fitness loss for 'deleterious' traits.

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kamintar t1_j9iwty4 wrote

You explain this so eloquently and clearly, the mark of true knowledge. Thanks for sharing.

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Lets_Go_Why_Not t1_j9i1ik4 wrote

They certainly can be, for sure, though sometimes the mechanisms can be blurred - for example, is a sexual preference for greater height in place because taller people are inherently better at something because of the height OR is it simply that people with access to sufficient food and nutrients (through a variety of mechanisms) are taller, thus height is just an indicator, rather than a survival mechanism itself. And that doesn’t even begin to account for sexually selected traits that are theorized to be technically detrimental to day-to-day survival BUT that kind of indicate to potential mates “if I can afford to waste energy on this useless trait, imagine how awesome I am in everything else!” (eg peacock feathers).

In other words, sexual selection can be weird to untangle.

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hugthemachines t1_j9ixhfq wrote

That is very interesting considering how often I hear people explaining attraction for certain attributes connected to better survival of the off spring.

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Lets_Go_Why_Not t1_j9iywvl wrote

Ultimately, being able to attract the interest of a partner is directly connected to better survival in that offspring that are actually born have a better chance of surviving than those that never have the opportunity....it's just the thing that attracts that partner may not contribute to survival after they are born.

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