Week 6: Vision and evolution of the Eye

This week's topics of discussion were by far the most intriguing to me.  We touched on the anatomy and physiology of the eye and the evolutionary aspects in the birds of paradise. This brought me back to the good memories of biology class in junior year of high school. Before I got into my thoughts about the birds of paradise in New Guinea, watch the videos below to have a better understanding of what I will be talking about.

 https://www.youtube.com/watch?v=W7QZnwKqopo

https://www.youtube.com/watch?v=YTR21os8gTA

As you can see, these birds have exotic practices to find a mate.  The males have all these extra
features on their body that seem to have no other function other than to attract a mate. Now the question is why would female birds find these exotic feature advantageous to reproduce with, such as the yellow poof or the long antenna like things in the picture below.


 https://www.youtube.com/watch?v=W7QZnwKqopo


http://ngm.nationalgeographic.com/2012/12/birds-of-paradise/laman-photography

The reason why it is so puzzling to scientists around the world is because of the natural selection process and evolution. The driving force of the way life came to be as it is today is natural selection and other factors of evolution.   Charles Darwin's idea of natural selection is the gradual process of having the  advantageous traits in a population be passed on and the disadvantageous traits become less common.  This happens through survival of the fittest, organisms with traits that help them survive and evade predators or disease will live to reproduce another generation. On the flip side, organisms within a species who have traits that are a disadvantage are usually more vulnerable to death and not being able to reproduce.

With that in mind, think back to the videos and the way that one bird cleared out a whole space on the ground to perform in mating dance.  In addition look at the pictures and notice that these birds are brightly colored and have these extra features that can get in the way of make them less agile. Now take in account their habitat, they live in tropical rain forests where the best protection from predators is to camouflage in the dense forest and these birds to the exact opposite. Their common predators include humans, snakes, and larger birds.  It puzzled me how these seemingly disadvantageous traits kept getting passed on until I found out that one possible explanation is that the females look for a lot of baggage and bright colors because if these birds can survive with the disadvantageous traits making them more susceptible to disease and predators then that means they must be quite resistant.

It is definitely an interesting way to look at it because it kind of goes against the traditional ideas of natural selection and survival of the fittest.  It shows that even if a bird has advantageous traits that make it camouflaged from predators and survives to live a good life, the traits will ultimately not be passed down to another generation if it can't find a mate.  This demonstrates the impact and importance of the female birds preferences in finding a mate.

http://a-z-animals.com/animals/birds-of-paradise/
http://evolution.berkeley.edu/evolibrary/article/evo_25