Matt Ridley is the author of provocative books on evolution, genetics and society. His books have sold over a million copies, been translated into thirty languages, and have won several awards.

I was giving a talk in Bozeman, Montana, last night at an event to celebrate the 30th anniversary ofPERC, a think tank that encourages private approaches to wildlife conservation and free-market environmental solutions.

Just as I uttered the words "of course, things will still go wrong", there was a huge thunderclap, the lights went out and the slide projector died.

I spent an afternoon this week getting a personal tour of a cast of the skeleton of Ardipithecus from Tim White, the leader of the team that decsribed it. Call me a nerd, but I found it spine-tingling to hold in my hands the skull of a 4.4.million year old creature that might be very close to my own ancestor.

But it was the details that stole the show. The lack of sharpening on the rear of the canines (unlike a chimpanzee), the flared pelvis of a regular biped, the curved but relative short metatarsals of the foot, the hints of very little sexual dimorphism.

The ecology, too, is intriguing. The Afar depression was not such a depression then, and the weather was sufficiently damp for a fairly rich forest to be growing there, albeit with patches of grassland. By far the commonest antelopes were woodland-dwelling, browsing kudu. Ardi herself ate fruits and nuts from trees, not grasses -- this can be decided by isotopic analysis -- and she was a good climber as well as a walker. Her molar teeth had not grown robust like those of Lucy, for grinding grass seeds and roots, but nor had they shrunk for processing soft fruit as those of modern chimpanzees have.

Frederic Bastiat's writings are full of brilliant rebukes against the restriction of trade, and the curtailment of human happiness such restrictions always bring. But it is in a discussion around the state funding of the arts that Bastiat most clearly articulates the pessimism behind the bureaucratic state and the life-enhancing optimism of those who believe in human freedom.

Our adversaries consider that an activity which is neither aided by supplies, nor regulated by government, is an activity destroyed. We think just the contrary. Their faith is in the legislator, not in mankind; ours is in mankind, not in the legislator.

The latest evidence for the rationality of such optimism can, of course, be found in my book.

Nick Wade has a good piece in today's New York Times about John Mitani's chronicling of warfare between troops of Chimpanzees in Uganda.

Dr. Mitani's team has now put a full picture together by following chimps on their patrols, witnessing 18 fatal attacks over 10 years and establishing that the warfare led to annexation of a neighbor's territory.

The fact that male chimpanzees systematically and stealthily patrol their boundaries in groups to kill neighbouring males has been known for a long time in Gombe in Tanzania, but critics have charged that it was unnaturally caused by human feeding of the chimps. That now seems unlikely.

Pertinent to my recent response to New Scientist on ocean acidification, Willis Eschenbach has a fascinating piece at Wattsupwiththat on a study of ocean pH along a transect from Hawaii to Alaska. Turns out that the further north you go, the less alkaline the ocean:

As one goes from Hawaii to Alaska the pH slowly decreases along the transect, dropping from 8.05 all the way down to 7.65. This is a change in pH of almost half a unit.

The study also measured the change caused by carbon dioxide from industry:

When I joined the Economist in 1983, Norman Macrae was the deputy editor. He died last week at the age of 87. Soon after I joined the staff, a thing called a computer terminal appeared on my desk and my electric typewriter disappeared. Around that time, Norman wrote a long article that became a book about the future. It was one of the strangest things I had ever read.

It had boundless optimism --

Over the last decade, I have written many articles in The Economist and delivered lectures in nearly 30 countries across the world saying the future should be much more rosy. This book explores the lovely future people could have if only all democrats made the right decisions.

As part of an `interview' with me, New Scientist published a critique by five scientists of two pages of my book The Rational Optimist. Despite its tone, this critique only confirms the accuracy of each of the statements in this section of the book. After reading their critiques, I stand even more firmly behind my conclusion that the threats to coral reefs from both man-made warming and ocean acidification are unlikely to be severe, rapid or urgent. In the case of acidification, this is underlined by a recent paper, published since my book was written, summarising the results of 372 papers and concluding that ocean acidification `may not be the widespread problem conjured into the 21st century'. The burden of proof is on those who see an urgent threat to corals from warming and acidification. Here is what I wrote (in bold), interspersed with summaries of the scientists' comments and my replies.

Take coral reefs, which are suffering horribly from pollution, silt, nutrient run-off and fishing - especially the harvesting of herbivorous fishes that otherwise keep reefs clean of algae. Yet environmentalists commonly talk as if climate change is a far greater threat than these, and they are cranking up the apocalyptic statements just as they did wrongly about forests and acid rain

Andy Ridgwell says `I agree that at least for some reef systems, other, and more local human factors such as fishing and pollution may be the greater danger' and Jelle Bijma says `I do agree that, for example, pollution and overfishing are also important problems, some even more important than the current impact of ocean acidification'. It was not therefore accurate of Liz Else to say that the critics accuse me of failing `to recognize that there is more to the health of corals than the amount of bicarbonate in the sea' They do not - she has misrepresented their views and mine.

Update: now that I have seen the five scientists' comments, I find that remarkably they support and vindicate each one of my factual statements. I have posted a detailed analysis in a separate blog post.

Here's a letter I just sent to New Scientist:

In her misleading article about my book, among other errors Liz Else wrongly states that I `failed to recognize that there is more to the health of corals than the amount of bicarbonate in the sea'. Yet I clearly state in my book: `take coral reefs, which are suffering horribly from pollution, silt, nutrient runoff and fishing'. After doing the interview, Else asked me for proof of a statement in my book that `Even with tripled bicarbonate concentrations, corals show a continuing increase in both photosynthesis and calcification.' Presumably this was because her unnamed `experts' had challenged this statement. I was happy to supply her with the following extract from Craig Idso's book (`CO2, global warming and coral reefs'), which I cited in my book, and with the reference it cites (Herfort et al 2008. Journal of Phycology 44: 91-98): `This work reveals that additions of HCO3- to synthetic seawater continue to increase the calcification rate of Porites porites until the bicarbonate concentration exceeded three times that of seawater…Similar experiments on Acropora species showed that calcification and photosynthetic rates in these corals were enhanced to an even greater extent, with calcification continuing to increase above a quadrupling of the HCO3- concentration and photosynthesis saturating at triple the concentration of seawater'. I am sorry that instead of quoting this exchange between us, Else chose to fall back on unsubstantiated accusations of `misconceptions, selective reporting and failure to see the significance of historical changes in ocean acidity'. I took the trouble to back up my claims; she should have done so for her accusations.

I just read a wonderful book Hybrid: the history and science of plant breeding by Noel Kingsbury.

It contains a charming story, of a Moravian priest called Father Schreiber, who was more interested in horticulture than holiness, and whose parish included Gregor Mendel's birthplace, Hyncice. As Kingsbury tells the tale:

Schreiber also had to face opposition, or at least suspicion, from a conservative peasantry. So in order to distribute new fruit varieties, he and the countess [Maria Walpurga Truchsess-Zeil, no less] developed a technique that has been used more than once down the ages in order to bring new genes to the countryside: subterfuge. A nursery for trees was established and word put out that these valuable seedlings were under guard, the guards being instructed to make a lot of noise if they heard anybody but not to actually arrest anyone. In a matter of days, all the seedlings had been stolen.

I have written a longish piece about the human footprint on the earth, avaliable as a `ChangeThis' manifesto here

Here are a few extracts:

George Monbiot's recent attack on me in the Guardian is misleading. I do not hate the state. In fact, my views are much more balanced than Monbiot's selective quotations imply. I argue that the state's role in sometimes impeding or destroying the process that generates prosperity needs to be recognised, as people from enslaved ancient Egyptians to modern North Koreans could testify. But as I mention in my book, I don't think that free markets, especially those in assets, should be completely unregulated. I do argue that free and fair commerce has the power to raise living standards.

Unlike Monbiot's article, my book isn't about me. It's about the billions of other people in the world who, through ingenuity, exchange and specialisation, have generated remarkable prosperity.

Monbiot, remember is the man who once wrote: ``every time someone dies as a result of floods in Bangladesh, an airline executive should be dragged out of his office and drowned.'' (see, George, two can play at selective quotation).