My bruised human ego

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This is the best photo I got of a group of baboons who gave me quite an experience the other day.

On a sandy fynbos trail, I rounded a corner obscured by vegetation and came abruptly face to face with a troupe of seven of these creatures. The closest member was only 3 metres from me. All of them were stopped, standing or sitting,  looking at me as I did the same. My first reaction was one of awe, these creatures are impressively muscular and intimidating up close. One of them, a very large male, was wearing a radio collar. My second instinct was to take advantage of the photo opportunity, but my camera was in my backpack.

My only close experience with monkeys comes from Indonesian macaques, and extrapolating from the damage these ones wreak on tourists’ belongings I was not keen to get the baboons interested in anything I owned. I was also aware that some baboon troupes in the Cape have a reputation for raiding. Bins, bags, picnics, cars, houses are all fair game. They have overcome their fear of humans and are now a famous nuisance requiring full time management.

My bag therefore remained zipped and in place on my back. I raised my arms and hissed, to try and persuade them off the trail. One of the leaders began to advance on me, and the others stood up to follow suit.

Finally, I was forced to concede the path to the baboons. I back-stepped into the bush beside the track, allowing them a 2 metre thoroughfare which they calmly took in an orderly and nonchalant fashion. Only after passing me, when their backs were exposed, did they pick up speed into a quick trot for a dozen metres to put some distance between us.

 

Red Hill fynbos track

Kleinplaas Dam fynbos track

 

Die Selfish Gene, Die.

I was recently asked by a friend for my opinion on David Dobbs’ piece “Die Selfish Gene, Die.” The article spins a yarn on why Richard Dawkins’ “Selfish Gene” thesis is sunk and the battle for updating it with a new theory of “genetic accommodation”.

It has attracted much attention as a great piece of science writing popularising the battle for a paradigm shift in genetics and evolution. Unfortunately its inaccurate and a bit too puffed up on its own bravado. My brief statement is below, however Jerry Coyne, Richard Dawkins and PZ Myers provide a more thorough commentary.

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Dobbs’ article describes a battle of two straw men. 

The term “genetic accommodation” is a new one to me, but the description of it sounds like phenotypic plasticity together with pleiotropy and epigenetics in a fancy jacket, but maybe we needed a word for that. Nonetheless, contrasting it with the selfish gene hypothesis is a false dichotomy. The messy truth for many traits lies somewhere in between, where the convoluted cascade of genetic-epigenetic-genetic interactions involved in “expression” will face selection as soon as its resultant phenotype hits the environment. 

The complexity of gene expression via interactions between genes and epigenetics (non-DNA inheritance) is blowing a lot of our heads off right now. It’s chaotically complex in there. I think the article therefore makes a mistake in referring to “gene expression” as a singular process.

Work I saw presented by John Mattick from the Garvan Institute provides a good example. Gene expression in human neurons can be governed by the interaction of RNAs, binding to “non-coding” DNA and interacting in 3 dimensions with complex protein molecules. In other words, it starts with a gene, which makes an RNA. That RNA’s action depends on the interaction between its sequence and where it binds on the genome. The sequence of DNA to which it binds, governs how it binds; simple like a zip, or more complex and looped up. Along comes a protein molecule (encoded earlier, elsewhere, by another gene) and the molecular properties of that gargantuan tangle of amino acids determine how it interacts with that looped up bit of RNA stuck to the DNA. This binding provides but a step in some long chain of protein interactions in a biological pathway. 

This kind of combinatorial complexity of interactions provides huge plasticity of action for a single set of tools (the genome).

One could argue that the first step of environmental interaction of any gene is the “environment” of the genome and epigenome it inhabits. This could still be squared with the selfish gene thesis.