Welcome to the eighth edition of Berry Go Round, the carnival that celebrates the blogosphere’s coverage of all things botanical. I’m not going to try and top Bora’s magnificent LOLPlant effort, so without further ado, here’s the good stuff:
The complex cells that make up plants and animals only survive today because their ancestors formed partnerships with bacteria. In a previous post, I wrote about a microbe called Hatena, which provides us with a snapshot of what the early stages of this alliance might have looked like. Hatena swallows an alga which becomes an integrated part of its body.
Millions of years ago, the ancestors of complex cells did the same thing, taking in bacteria and merging with them to form a single creature. Today, these integrated bacteria are mitochondria, which provide us with energy, and chloroplasts, which allow plants to photosynthesise. Hatena and its algal partner show us what the early steps in this vital alliance might have looked like. Now, another species of bacteria, Carsonella ruddii, embodies a later stage – the transfer of genes.
Typically, the lodging cell would shunt some of its genetic material over to its host. It has permanent room and board and can afford to rid itself of excess genetic baggage that was once necessary for its free-living existence. That’s exactly what Carsonella has done, but it has taken this process to an extreme. It has transferred so many of its genes that it now has the smallest genome of any bacterium and it cannot possibly survive outside of its host.
Conservationists often object to wind farms because of the possibility that they could kill birds. But birds aren’t the only flying animals to be taken out by turbines – it turns out that bats often lose their lives too, and not in quite the way you might imagine.
Recently, scientists have noticed a large number of dead bats at wind farms around the world. The turbines seem to be taking a particularly heavy toll on migratory species and while it was clear that the scale of these deaths is much larger than expected, it’s less clear why they’re happening at all.
Bats can fly through pitch-darkness through echolocation – a superb biological sonar system that’s particularly good at detecting moving objects. With such state-of-the-art equipment, it’s difficult to believe that these accomplished aeronauts could simply be blundering into the spinning blades. Now, Erin Baerwald and colleagues at the University of Calgary think that they have found the mystery killer, and it’s one that is invisible to the bats’ sonar – areas of low pressure.
As the blades of wind turbines spin, they reduce the pressure of the air around them. As bats fly into these low-pressure zones, the sudden change causes the air in their lungs to expand faster than the bats can exhale. The technical term is “pulmonary barotrauma”. In three syllables, “their lungs burst”. Areas of low pressure are essentially invisible – even if the bats’ sophisticated sonar guides them through the spinning blades, they wouldn’t be able to sense these danger zones until it’s too late.
To those of you who are going to the London Science Blogging conference on Saturday, I’ll see you there. I’ll be at the morning sessions and the lunch break but will probably have to leave early so if you want to say hi, catch me then.
I look like the photo on the left.
Yesterday, I wrote about selfless capuchin monkeys, who find personal reward in the act of giving other monkeys. The results seemed to demonstrate that monkeys are sensitive to the welfare of their peers, and will make choices that benefit others without any material gain for themselves. Today, another study looks at the same processes in a very different sort of cheeky monkey – human children.
Humans are notable among other animals for our vast capacity for cooperation and empathy. Our concern about the experiences of other people, and our natural aversion to unfair play are the bedrocks on which our societies and moral codes are built. But are we born with this penchant for equality or does it develop as we grow up?
To find out, Ernst Fehr from the University of Zurich played a series of three decision-making games with 229 children between the ages of 3 and 8. The study used similar methods to those employed by Frans de Waal in his experiments on capuchins, but with some notable differences. For a start, the choices were anonymous. In each trial, a child had to decide between two ways of distributing sweets between themselves and a second child, who was only ever represented by a photo.
There are some who say that helping others is its own reward, and many biologists would agree. The fact that selfless acts give us a warm glow is evident from personal experience and neurological studies, which find that good deeds trigger activity in parts of the brain involved in feelings of reward. But feeling food by being good isn’t just the province of humans – monkeys too get a kick out of the simple act of giving to their fellow simians.
At the Yerkes National Primate Research Center, Frans de Waal‘s team of scientists have been investigating the selfless side of eight brown capuchin monkeys. Each monkey was given a choice between two differently coloured tokens. Both would earn it a rewarding piece of apple but only one token would net a slice for a second monkey sitting in an adjacent transparent compartment.
The chooser would benefit equally no matter what choice they made, so if they were completely cold to the needs of their peers, you would expect them to pick both tokens with equal frequency. Otherwise, the “prosocial” token which benefited a second monkey would be the favoured pick. Everything else begin equal, would the monkeys take the welfare of their fellows into account?
For centuries, farmers have known that their livestock not only gather in large herds but also tend to face the same way when grazing. Experience and folk wisdom offer several possible reasons for this mutual alignment. They stand perpendicularly to the sun’s rays in the cool morning to absorb heat through their large flanks, or they stand in the direction of strong winds to avoid being unduly buffeted and chilled.
But cows and sheep don’t just line up during chilly spells or high wind. Their motivations for doing so during warm, pleasant and unremarkable weather, or indeed in the dead of night, have been a mystery until now. In a new paper, Sabine Begali from the University of Duisburg-Essen in Germany spied on aligned herds of cows and deer using satellite images from Google Earth.
The images revealed a striking behaviour that had been going unnoticed for millennia, right under the noses of herdsmen and hunters – their herds were lining up in a north-south line like a living compass needle. Influenced by a magnetic sense that has only just become apparent, their default point of reference is not the source of wind or the angle of the sun, but the Earth’s magnetic poles.
I’m toying with the idea of publishing a book that compiles the best of Not Exactly Rocket Science from the last year. I’ll select about 60 or so of my favourite pieces from 2008 and transfer them from code and pixels to ink and paper. The plan is to launch the book in early November in time for the Christmas market.
So the big question is: would you buy it? And related questions: would you buy it as a gift for anyone? Would you recommend it to people? Is this a good idea or a silly one? Do any of you have contacts who could help to market something like this?
On 14 January 2005, Lawrence Summers (right), president of Harvard University spoke of the reasons behind the disproportionate lack of women in top-end science and engineering jobs. Avoiding suggestions of discrimination, he offered two explanations – unwillingness to commit to the 80-hour weeks needed for top level positions and, more controversially, a lower “intrinsic aptitude” for the fields. According to Summers, research showed that genetic differences between the sexes led to a “different availability of aptitude at the high end”.
For years, scientists have battled over the evidence for sex differences in scientific ability, using genetics, psychology and social sciences as their weapons. But often, they forget that this debate does not rage on in isolation – it is heard and processed by scores of young female scientists trying to make their mark in the field. A year after Summers’ incendiary remarks, a psychological study showed just how pernicious comments like these can be on this group of listeners.
Stereotypes famously reinforce themselves because people respond to them by acting out the stereotype. Black Americans perform worse in intelligence tests if their race is drawn to their attention. And in the UK, the media portrayal of our teenagers as boorish hooded thugs risks driving them further down that route.
But Ilan Dar-Nimrod and Steven Heine at the University of British Columbia reasoned that stereotypes are even more catastrophically self-fulfilling if genetics are thrown into the mix. Regardless of what geneticists know, a large proportion of the public still view genes as inescapable agents of pre-determination, setting your life and actions down a course you have little say over.