Natural selection: On fitness

20 Tuesday Mar 2012

Posted by sedeer in Evolution, Natural Selection

Tags

biology, Darwinism, Education, evolution, fitness, natural selection, Popular science, replicator, science, selfish gene, tautology

For the third part in my series about natural selection I’d like to address the concept of fitness. Thanks to the phrase “survival of the fittest”, fitness is quite a prominent idea in the popular perception of evolution. It was originally coined by Herbert Spencer after he read On the Origin of Species; Darwin adopted the phrase in later editions and it’s been popular ever since. Unfortunately, this glib phrase has often eclipsed a more accurate depiction of evolution, leading to some common misunderstandings. This confusion arises because “fitness” has a different meaning in evolutionary biology than it does in general usage. (Have a look at the earlier posts in this series if you haven’t already read them; the first was about the different modes of natural selection and the second discussed selection mechanisms, focusing on sexual selection in particular.)

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Social wasps are specialists at recognizing faces

16 Friday Mar 2012

Posted by sedeer in Evolution, Hymenoptera, Insects, Mind

≈ 3 Comments

Tags

animals, biology, Cognition, evolution, face, Facial recognition system, Insecta, Paper wasp, Popular science, science, Wasp

There’s lots of evidence that humans have a specialized mechanism for identifying and responding to faces; for example, people with a condition called prosopagnosia have difficulty recognizing faces but not other objects. A few years ago, researchers showed that individual paper wasps of the species Polistes fuscatus recognize each other’s faces; the same team has now gone on to show that, like humans, P. fuscatus accomplishes this via a specialized mechanism for facial recognition rather than through general shape or pattern recognition. This story is an excellent example of a complex cognitive ability being exhibited by a creature with a relatively simple nervous system.

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Redheads and pain: science or sensationalism?

12 Monday Mar 2012

Posted by sedeer in Genetics, Humans

≈ 2 Comments

Tags

animals, biology, Capsaicin, Human, Melanocortin 1 receptor, Pain, Popular science, Red hair, redhead, Redheads, science, science and society, Science communication

I’ve recently come across some press coverage reporting research by Danish scientists which has shown that “redheads feel pain differently than the rest of us”. I read the paper and thought it would be nice to write something short about it here, both for the change of tone and to give my own perspective on it.

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Natural selection: selection mechanisms, sex, and the brain

08 Thursday Mar 2012

Posted by sedeer in Evolution, Natural Selection

≈ 4 Comments

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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Thinking bees and the concept of “sameness”

22 Wednesday Feb 2012

Posted by sedeer in Hymenoptera, Insects, Mind

≈ 4 Comments

Tags

animals, bees, biology, Cognition, Hymenoptera, Insecta, Learning, Popular science, science

The ability to categorize objects or experiences as “the same” or “different” has generally been considered a relatively advanced cognitive capacity relegated solely to vertebrates (or perhaps even primates). However, in a study published in 2001, researchers found that honeybees are able to conceive of sameness and difference, showing that the capacity to make these abstract conceptual distinctions is more widespread than we had believed.