How Peacocks Got Their Tails - Fisher's Runaway Selection

Описание: Peacocks are famous for their long, beautiful tails. But how did they get them? Let's see what science has to say about peacock tails! Please subscribe to continue learning what makes life AWESOME: https://BioBush.tv/subscribe

The theory is called Fisher's Runaway Evolution. The key to the theory is a set of initial conditions. First, there must be a gene (or set of genes) for a trait on males, and a LINKED gene (or set of genes) that cause a preference for that trait in females. Linked just means they are on the same chromosome. Doesn't matter which one, as long as they are on the same one, so they are usually inherited together.

In this case, choosier females will choose males with more prominent traits, and their offspring will be BOTH choosier AND have more prominent traits. If this happens often enough in a population, the trait will start to "run away" and become increasingly pronounced, even to absurd-looking levels.

The weakest part of the entire theory is the idea that a set of genes can cause a preference in females. If we do not identify genes like this (which we have not) then we will need to update our model of how the peacock got its tail.

UPDATE: Harrison from ‪@TheWildlifeBrothers‬ pointed out that there is a paper which offers an alternative model (social effects) that might trigger Fisher's Runaway Selection. http://dx.doi.org/10.1111/j.1558-5646...

It took a long time for the theory to click in my head, so I hope this video helps you learn it faster than I did!

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Copyright

Video "Biomechanics-of-the-Peacocks-Display-How-Feather-Structure-and-Resonance-Influence-Multimodal-pone.0152759.s004" by Dakin R, McCrossan O, Hare J, Montgomerie R, Amador Kane S, via Wikimedia Commons (https://commons.wikimedia.org/wiki/Fi.... Used under Creative Commons cc-by 4.0.

Video "Real-time and slow motion video of peacock courtship displays" by PLOS Media (   • Real-time and slow motion video of peacock...  ). Used under Creative Commons cc-by 3.0.



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