A report today identifies two colonies of chimpanzees in a corner of Cameroon as the source of the HIV pandemic, suggesting that are the reservoir of the apparently harmless SIV virus that mutated when a hunter came in contact with chimpanzee blood. What’s particularly interesting is the timeframe:

Researchers believe the virus infected humans some time before the 1930s and was gradually spread by river travel. All of the rivers in Cameroon run into the Sangha, which joins the Congo river running past Kinshasa.

Trade along the routes could have spread the virus, which slowly built up in the human population….

The first clearly identified case of Aids reported in the United States was in 1981, though it seems an African American teenager died of it in St Louis in 1969.

Which does make you wonder how many other such viruses are building up out there. We sometimes think in the West that “modern medicine” understands everything, but as a the victim of a very nasty bug caught in India – variously diagnosed as chickenpox, typhus and “mystery tropical illness”, this last I’m sure the most accurate – I’ve was disabused of that myth.

Turning to more cheerful matters: the great riddle is answered – the egg came first.

Professor John Brookfield, a specialist in evolutionary genetics at the University of Nottingham, who was put to work on the dilemma, said that the pecking order was perfectly clear: the living organism inside the eggshell would have the same DNA as the chicken that it would become.

“Therefore, the first living thing which we could say unequivocally was a member of the species would be this first egg,” he said. “So I would conclude that the egg came first.”

Seems conclusive to me; an “almost-chicken” produced a chicken.

Somehow, though, I don’t think that will stop the debate, particularly in the pub around about closing time…

Two new discoveries are reminders that Homo sapiens sapiens is just another member of the animal kingdom.

Researchers have found that the gloriously named putty-nose monkey communicates in “sentences”, having a syntax that puts together two “words” to mean something entirely different to either of them:

The monkeys call out ”pyows” to warn against a loitering leopard and ”hacks” are used to warn about hovering eagles overhead. However, combining pyow and hack means something like ”let’s go”, according to scientists from the University of St Andrew’s.

This report, from the journal Nature, implies sophisticated linguistic processing in the monkeys’ brains – to ignore the very strong individual meanings of the calls and put together the new meaning. And since these are not particularly high-level animals — it would perhaps have been less surprising were this to be found in chimpanzees or gorillas — it suggests this ability must be widely distributed in the animal kingdom. It is not that animals are too dumb to “talk, just that we’ve been insufficiently intelligent or switched-on to understand them.

Speaking of chimps, it seems the mockers of Charles Darwin closer to the truth than they would have liked. For research also reported in Nature suggests that interbreeding between human and chimp ancestors went on for much longer than previously thought – indeed there was a split, then a hybridization between the two groups before the final split, much later than the previously estimated 7 million years.

All of that might be taken as a further push – which sadly seems to be needed – to care for all of our relatives, both close and more distant. That reflection comes from the news that India’s tiger population has probably halved in just four years. The wild populations may not last out the decade.