Natural selection: selection mechanisms, sex, and the brain

08 Thursday Mar 2012

Posted by sedeer in Evolution, Natural Selection

Tags

biology, brain, Education, evolution, natural selection, Popular science, science, selection, sex, sexual selection

This is second part in my series on natural selection. In the first part, I discussed different modes of selection; in this post, I’ll explain an important mechanism of natural selection which probably doesn’t get enough attention in basic biology courses. The idea, called sexual selection, dates back to Darwin, who dedicated over half of one of his books (The Descent of Man and Selection in Relation to Sex) to the subject. Sexual selection is based on the struggle to reproduce rather than the struggle to survive; this already gives us a hint that the term “fitness” has a different meaning in evolutionary biology than it does in common speech, which is a subject I’ll get to in a later part of this series.

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Natural selection: different modes

27 Monday Feb 2012

Posted by sedeer in Evolution, Natural Selection

≈ 5 Comments

Tags

biology, Education, evolution, natural selection, Popular science, Population, science, selection

I mentioned “directional selection” in an earlier post and someone asked about it, so I decided to take the opportunity to explain the process of natural selection in a bit more detail. I think there’s a tendency for people to have a very straightforward, simplified view of natural selection when they think about evolution. As with everything in biology, the real story is more nuanced and therefore more interesting. I’ll develop these ideas over a series of posts, starting with the different modes of selection in this post and moving on to different mechanisms in a future post. Understanding how the different aspects of natural selection interact is an important part of appreciating the complex and dynamic process of evolution, which is at the very core of biology and has generated all of the beautifully fascinating life we see around us.

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Five common biology myths (or “Science in the service of the anthropocentric patriarchy”)

15 Wednesday Feb 2012

Posted by sedeer in Bacteria, Evolution, Humans, Mind

≈ 15 Comments

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bias, biology, culture, Education, interaction, Popular science, science, science and society, Science in Society, society

In these “enlightened” times, people often try to use science to justify their social, political or ideological positions. While the influence of scientific research on our world view is commonly recognized, the converse dynamic gets far less attention. Cultural factors shape the sort of questions we ask and how we choose to interpret the answers; for example, despite the claim that the idea of evolution has radically altered our view of ourselves, it also often serves to reinforce existing social and cultural norms. Here are five commonly accepted biological “facts” which are untrue but are used to justify our conception of ourselves and our place in the world.

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Adam & Eve: Behind the Myth

08 Wednesday Feb 2012

Posted by sedeer in Evolution, Genetics, Humans

≈ 4 Comments

Tags

ancestry, animals, biology, Education, evolution, Human, Mitochondrial DNA, Mitochondrial Eve, out of Africa, Popular science, science, Y-chromosomal Adam

In a paper published in 1987 in the leading science journal Nature, researchers claimed to have identified a female from whom all humans alive today are descended, dubbed “mitochondrial Eve”; nearly ten years later, another group of scientists published findings identifying her male counterpart, “Y-chromosomal Adam”. The choice of names, though evocative, was unfortunate and uninformative, since the use of “Adam” and “Eve” has led to several major misunderstandings about these two ancient humans. In this post, I’ll try to clear up some of these misunderstandings by explaining what these terms actually mean and how scientists have gone about trying to identify our most recent common male and female ancestors.