The Red Notebook

Just came across this rather odd ‘humorous’ 1930 British newsreel on the British Pathé website:

Bizarro!

Who says the reporting of science in the media has gone downhill?

At the end of May, there was a news story doing the rounds about how bipedalism evolved in the trees and not, as has been traditionally thought, via knuckle-walking on the ground. Now, a new study says bipedalism evolved because it uses less energy than knuckle-walking.

What is an interested non-expert supposed to think? (Actually, for the record, as an interested non-expert, I didn’t buy the first story at all.)

Anyway, I only mention this second story, because it included a funny photo of a chimpanzee on a treadmill:

This one will have the animal rights people doing their nuts.

Here’s a nice example of an evolutionary arms race in action:

BBC: Butterfly shows evolution at work

Scientists say they have seen one of the fastest evolutionary changes ever observed in a species of butterfly. The tropical blue moon butterfly has developed a way of fighting back against parasitic bacteria.

Six years ago, males accounted for just 1% of the blue moon population on two islands in the South Pacific. But by last year, the butterflies had evolved a gene to keep the bacteria in check and male numbers were up to about 40% of the population. Scientists believe the comeback is due to “suppressor” genes that control the Wolbachia bacteria that is passed down from the mother and kills the male embryos before they hatch.

The parasitic bacterium can only be passed on through the female line of its host, so it evolved a mechanism to ensure that only female host embryos survive. But the dearth of male blue moon butterflies created a massive niche that was just crying out to be filled. Any mutation that enabled male butterfly embryos to survive the bacterium’s attack would spread quickly through the population. Which is exactly what appears to have happened, and the butterfly sex ratios are rapidly returning to normal.

The development of resistance to the wolbachia bacterium is a lovely example of Natural Selection in action: a single beneficial mutation spreading quickly through a severely depleted population. The alternative was extinction.

With males having dropped to 1% of the population, the blue moon butterfly has just come through an evolutionary bottleneck. Evolutionary bottlenecks are a fascinating subject in their own right. They are a means by which rare, possibly disadvantageous traits can become more common in a population by serendipitously piggybacking on the back of strongly selected beneficial ones. Genes mutate, but it is individuals that are selected. If a particular genetic mutation gives an individual a major selective advantage in an evolutionary bottleneck situation, that individual’s genes are likely to become more common in the general population warts and all: the benefits of the highly advantageous mutation might well outweigh the penalties of any disadvantageous ones. Evolutionary bottlenecks lead to in-breeding.

Recent DNA studies indicate that our own hominid line went through an evolutionary bottleneck in its dim and distant past, which left us and our chimpanzee cousins more vulnerable to genetic disease such as cancer. It would be interesting to know what other traits piggybacked on the blue moon butterfly’s highly advantageous new wolbachia resistance.

New Scientist: Why bonobos make love, not war

… Pygmy chimps or bonobos are both literally and metaphorically our kissing cousins. If you know them at all, it is probably as the most highly sexed of all the apes, but they are also considered by many to be our closest living relative—closer even than the common chimp.

This is incorrect. Bonobos are not more closely related to us than are chimps, nor vice versa; bonobos and chimps are equally closely related to us.

As the (subscriber only) article goes on to explain:

Somewhere between 6 and 8 million years ago, our ancestors split from the line that would become today’s two species of chimps. Then around 2.5 million years ago, bonobos and common chimpanzees went their separate ways.

Two generations ago, my immediate Carter ancestor (my father) split from the line (his brother’s) that would become my two cousins. Ignoring our maternal lines for the sake of the analogy, to say that I am more closely related to one of my cousins than the other is ridiculous, as they shared a common ancestor (my uncle) more recently than they shared a common ancestor (my paternal grandfather) with me. The same argument goes for chimps, bonobos and humans: if bonobos are our kissing cousins, then chimps are their (less affectionate, equally closely related to us) siblings.

The rest of the article is, however, very interesting. It argues that living in areas with more abundant, nutritious, protein-rich plants meant that there were not the same selective pressures on bonobos to evolve/devise methods of food prepartion—including, perhaps, the use of tools. Instead, the plentiful supply of food has made bonobos’ feeding time more of a social activity than a competitive one, which could explain their more peaceful and sociable (to put it mildly) lifestyles.

It’s a nice idea, but I’m not sure how you could test it.

I appreciate I’m probably being a bit unfair quoting from a brief news article, but is this a total non-story or what?

BBC: Study uncovers ‘chimp cross code’

Experts studying chimpanzees while investigating the evolution of human social behaviour have uncovered their ability to safely cross roads.

They said the discovery has shown chimps’ ability to cope with the risk of man-made situations…

It found the dominant adult males took up protective positions in the group when it was tasked with crossing roads…

The study has built on prior research showing that adult male monkeys took similar action to reduce the risk of being attacked by predators when travelling towards potentially unsafe areas, such as waterholes.

Kimberley Hockings, who worked on the study, said: “Road-crossing, a human-created challenge, presents a new situation that calls for flexibility of responses by chimpanzees to variations in perceived risk, helping to improve our understanding about the evolution of human social organisation.

In other words, what they appear to be saying is that, when presented with an unusual and/or potentially dangerous situation, dominant male chimps and monkeys take protective positions in front of and behind the group. An interesting, if pretty unsurprising observation.

But why do the people carrying out the study think that road-crossing presents a new situation that calls for flexibility of responses? Aren’t the chimps simply giving a perfectly normal response when presented with a potentially risky situation? And why on earth do they think this is going to teach us anything about the evolution of human social behaviour? Don’t loads of other animals (elephants, for example) do exactly the same thing?

I’m sure we can make certain inferences about the evolution of human behaviour by studying chimps, but I can’t help feeling people read far too much into such studies. Why not study the chimps for their own sakes, rather than trying to bring in pretty tenuous links to human behaviour?