"The degree of predominance of the right hand for gestures is one of the most pronounced we have ever found in chimpanzees in comparison to other non-communicative manual actions. We already found such manual biases in this species for pointing gestures exclusively directed to humans. These additional data clearly showed that right-handedness for gestures is not specifically associated to interactions with humans, but generalizes to intraspecific communication", notes Prof. Hopkins.

The French members of the team, Dr. Adrien Meguerditchian and Prof. Jacques Vauclair, from the Aix-Marseille University, say: "This finding provides additional support to the idea that speech evolved initially from a gestural communicative system in our ancestors. Moreover, gestural communication in apes shares some key features with human language, such as intentionality, referential properties and flexibility of learning and use".

Hemispheric lateralization of linguistic, and presumably pre-linguistic skills is a fact, but there is no satisfactory answer to the question of why it should have evolved. It doesn't seem likely that it was to solve a capacity problem, although that remains a possible explanation. More convincing is the idea that there is an advantage to handedness. William H. Calvin, in The Throwing Madonna: Essays on the Brain, speculated that one-handed throwing could have been the crucial advance that gave early humans their survival advantage as against other apes, and that the requirement for intricate sequencing of motor actions was best fulfilled in one hemisphere and was then taken advantage of by language when it came along. But really this is just an elaboration of the capacity argument, and more convincing (but only just) is the idea that in gestural communication there is a group advantage if everyone gestures with the same hand, to avoid the need to apply a mirror transformation to the gestures you see when they are made by a left handed person, with some possible dangers of misinterpretation.

Whatever the original reasons for handedness, meaning left-brain dominance in certain functions, the fact that humans are mostly right-handed is of course just a random result. Evolution had to pick either left or right, and metaphorically it spun a coin, which happened to land right side up.

The studies were conducted on adjacent dialects of the native white-crowned sparrow over a 30 year period, from the late 1960s to 1998. The researchers hypothesised that the growth of urban sprawl in the San Francisco area would have become a selection pressure on the birds. 'Urban noise, which is louder at lower frequencies increased during our study period, and therefore it should have created a selection pressure for songs with higher frequency,' say the researchers.

Researchers made recordings of the birds in 1969, 1970, 1990 and 1998. Three 'dialects' were recorded in 1969, but by 1998 the one with the lowest minimum frequency had disappeared and the minimum frequencies of the other two dialects had increased. The dialect with the highest frequency had become dominant.

'In response to high levels of low-frequency ambient noise, urban birds have songs with higher frequencies,' says the study.

Bird song is normally stable over protracted periods of time, and the results suggest that, as with human languages, the actual songs of birds are cultural constructs, even if the facility for song, like the facility for language, is a genetic adaptation. Although these sparrows have a generation of only two years, there hasn't been enough time for there to be a genetic explanation for the frequency changes.

Something comparable was reported among two groups of macaques in Japan. One group was formed by 23 monkeys living on the southern Japanese island of Yakushima, and the other group comprised 30 descendants from the same tribe moved from the island to Mount Ohira, central Japan, in 1956. Results showed that the island group had a tone about 110 hertz higher on average than the one taken to central Japan.

Nobuo Masataka, professor of ethology at Kyoto University's Primate Research Institute, said: "Differences between chattering by monkeys are like dialects of human beings".

Monkeys on Yakushima Island have an accent with a higher tone because tall trees on the island tend to block their voice, Masataka said. "On the other hand, monkeys on Mount Ohira do not have to gibber with a high tone as trees there are low," he said. "Each group adopted their own accent depending upon their environment."

This suggests differences in voice tones are not caused by genes, Masataka said, adding the results "may lead to a clue to the origin of human language."

The male Augrabies Flat Lizard is a highly territorial animal: fully grown adult males dominate their territories, which contain multiple females - harems - by attacking and driving off younger males.

The adult males are highly coloured whereas females are a dull brown colour. A team of South African and Australian researchers has discovered that some young male lizards protect themselves from older males by pretending to be females, gaining access both to a territory and its resident females, where they are probably a lot more welcome than the Count and his men were.

As juveniles, all males look like females before gradually developing their extravagant adult male coloration at the onset of sexual maturity. Young males are most vulnerable to aggressive adult male rivals when these first signs of masculinity develop. Experienced males will chase and bite their young rivals.

"Young males purposefully only develop colours on their belly, so they reach sexual maturity by still looking like a female," says co-author Associate Professor Scott Keogh, of the School of Biological Sciences at the Australian National University. Professor Keogh says that the young transvestite males appear to have a dual advantage: “They can avoid potentially dangerous bouts with dominant males and still have access to normally inaccessible females.”

“By delaying the onset of colour to a more convenient period, these males (termed she-males) are making the best of a bad situation,” said team member Associate Professor Martin Whiting of the University of the Witwatersrand. An immediate advantage of this phenomenon is freedom of movement in the normally treacherous zones which make up the territories of highly aggressive males that already have fighting experience. At the same time, the female mimics are able to court the myriad of females that share the territorial male’s residence.

The researchers also tested whether she-males are able to mimic the chemical ‘signature’ of females. In a clever experiment performed in the wild, they removed all pheromones and skin lipids that might signal gender and relabelled a group of females and she-males with either male or female scent, before presenting them to typical adult males. Males use their tongues to sample chemical scent and responded by courting she-males labelled as females, but not she-males labelled as males. “Males are fooled by looks, but not by scent” said researcher Dr Jonathan Webb of the University of Sydney. “She-males are able to maintain this deception by staying one step ahead of a prying male, and thereby avoiding a nosey tongue that might give the game away.”

Question: at what level do the young transvestite males 'know' that they are deceiving the older males? Clearly a lizard can tell a male from a female both by sight and by smell. A she-male is aware at some level that it doesn't look like an older male - it has to, or its behaviour would be a give-away on the older male's territory. It has to walk and behave like a female, or it would immediately be spotted and attacked by the reisdent tyrant male. The lizard is not 'conscious' of course, in the sense of being self-aware in the way that humans are. But some part of its brain knows that it looks like a girl. An early component of intentionality.

The team used rules to exclude effects that might have resulted from sex, hierarchy, age, and friendship: "Everything I could come up with," Gomes says. She concludes that the only way to explain the symmetry of grooming exchanges between pairs over time is through reciprocity. "If you don't have a set price, then you're susceptible to being cheated and cooperation would probably break down."

So far, so good, and so classical, but Gomes goes on to say that the accuracy of the exchanges is more likely to be driven by an emotional agenda than a cognitive social calculus. "It does not necessarily have to be a cognitive process," she says, "it could be emotional." Gomes hypothesizes that chimpanzees - and by extension, humans - use fine adjustments to levels of endorphins to associate particular levels of generosity or meanness with individuals, and it's then hormonal motivation that causes the tit-for-tat behaviour.

While not excluding a major affective element in relationships, which indisputably exists, this view seems to deny the very adaptive advance which made human group social life possible, that being the evolution of a cognitively and cortically based social calculus. The vast enlargement of the neo-cortex in primates and then in humans cannot be adequately accounted for other than by the need to store enormous volumes of data about the historical relationships between members of the group, and as much between other members of the group as about one's own relationships. Think soap operas. Your endorphins may help you assess the state of things between you and your mates, but they won't help you much when it comes to understanding why Joe dumped Jane in favour of Chardonnay.

As well as enabling the matrix of extended group relationships, cognitive reciprocity led to exchange in goods, ie trade, the other key building block, after the group itself, of the society of which we are all members. The notions of fairness, value and trust that originally developed and expressed themselves through behaviours such as grooming and food-sharing underlie all types of trading activity: it seems intuitively implausible, even unworkable, that they could be successfully underpinned by a hormonal mechanism rather than a cognitive one.

The research, by graduate student Michael Sheehan and assistant professor of ecology and evolutionary biology Elizabeth Tibbetts, suggests that the wasps' social interactions are based on memories of past encounters rather than on rote adherence to simple rules.

Until now it was assumed that all social insects had very limited memories. Honeybees can remember where they've found nectar, "But those memories are pretty fleeting," Sheehan said. "There seems to be a limit to the number of things they can juggle in their head at one time."

Tibbetts had previously showed that the wasps recognize individuals by variations in their facial markings and that they behave more aggressively toward wasps with unfamiliar faces. In the new research, Sheehan measured aggression between 50 wasp queens in four different encounters over eight days. On the first day, two wasps that never had met were placed in an observation chamber for a day and their initial interactions videotaped. Then the pair was separated, and each wasp was put in a communal cage with 10 other wasps. A week later, the pair met again, and again their behavior was videotaped.

It was clear from teh results that the wasps treated each other better during their second encounter than when they were strangers, suggesting they remembered each other. "Instead of trying to bite each other and really have a rough-and-tumble encounter, they just sort of hung out next to each other when they met the second time," Sheehan said.

Recognition matters to the wasps because Polistes fuscatus females often share nests, so that it is adaptive for them to be able to recognize nest-partners. Most social insects use smell to identify nest-partners; separate research by Wulfila Gronenberg, associate professor of neurobiology and ecology and evolutionary biology at the University of Arizona, and who had previously worked with Tibbetts, has shown that in the paper wasp, the antennal lobe (used for smell recognition) is smaller than in other wasps, while the so-called mushroom body subcompartments, which integrate information from the senses and help control learning and memory, were not any larger than usual.

Sheehan points out that the findings of the Michigan research challenge assumptions about social cognition, which is generally thought to require a large and advanced brain.