How Sex Drives Evolution -Metacognitive Blog #1
Metacognitive Blog Project
Coyne, Why Evolution is True “How Sex Drives Evolution”
p.157-162
For this series of blogs I originally had a couple of different articles in mind from various science magazines. However, as I started sifting through my iBooks I came across the book Why Evolution is True. Although I had read this book a few years back I thought it would be a fun way to tune up my knowledge on this particular topic. Also, this book may serve as a valuable resource for a future unit on Evolution. It is thorough and a much easier read than and textbook selections I have encountered thus far on the subject. The reason I choose a chapter in the middle was because sex is sexy and interesting.
Before I read this selection I wonder about various species of birds I have read about and seen in nature documentaries. I also think about the male birds and what it takes to get a mate and insects battling it out up in a tree.
The Chapter begins with a quote from Charles Darwin dealing with male peacocks and birds of paradise about the pains associated with their vibrant displays. This immediately puts me in the Austin Zoo with my daughter on a search for peacock and chicken feathers. I also hear David Attenborough’s British voice in my head talking birds and such. The next few paragraphs give various other examples of supposed maladaptation at the cost of beauty. I imagine a plume of feathers in a fox’s red soaked jaws and a puddle of blood on the ground. I then find myself drawing comparisons to the human race but get bored with that line of thinking and regain focus on the text in front of my face. Then I get to the word ‘impendent’. Not able to recall this word results in a two touches of my pointer finger and a definition…a hindrance or obstruction. I do not miss a print dictionary. Ok, back to it. Another quote from Darwin where he states that “the site of a peacock’s feather makes [him] sick” makes my brain laugh. This brings the author to other examples of strange adaptations such as the inflatable vocal sack of a Central American frog that allows the bachelor the ability to serenade potential mates all night long. This comes at the cost of being located by a hungry bat or other frog eater. Coyne reminds the reader that there is no speculation whether or not these traits come at a cost. They do. The cost is a greater risk of predation or less fitness due to the metabolic demands for looking “sexy”.
A few terms are mentioned and described in the next few paragraphs. One is ‘sexual dimorphism’, differing traits between male and female. Several examples of this are given and illustrations of fish, birds and beetles are thrown in as well. By this time, my metacognition has slowed and I start to long for the end of this exercise. It may be that around 9:00pm my thinking about thinking automatically turns to thinking about sleeping. BUT onto the solutions…”why these costly traits evolved”. The reason is an increased chance of passing on some daddy DNA. At this point my mind has recreated all the YouTube videos of animals mating and the silly noises that accompany the visual. Then I start to envision male giraffe duking it out, neck to neck. Wow! Fortunately, I regain my focus and make the final push. It feels like a logically stopping point when the author explains how the benefits outnumber the cost for these fancy males for each of the past examples. I predict the chapter will continue with a more detailed explanation on costs and benefits and the types of sexual selection. AND…of course there will be examples in every paragraph. Good night.