At a local scale diversity has increased a lot: “The number of species living in virtually every country or island has already increased during the period of human influence, and numbers continue to increase.” The fauna and flora of Britain are much richer today than 10,000 years ago as a result of farming, towns, gardening, climate change and the deliberate introduction of exotic species. Thomas finds the same to be true in tropical forests in Cameroon, Costa Rica and Brazil: the net effect of some human disturbance can be more biodiversity.
You can resent some of the exotic species (I do) but you should pause to recognise that in terms of the functioning of ecosystems, there has been mostly improvement. In an extreme case, Ascension Island was a barren volcanic rock with a few ferns on its summit. It is now a semi-green island capturing more moisture from the wind, thanks to a deliberate effort, begun by Charles Darwin, to enrich its ecosystem.
Professor Thomas, an ecologist and evolutionary biologist from York University, has produced an immensely significant book. It is fluently written, carefully thought through, ruthlessly argued, neatly illustrated with case studies — and shockingly contrarian. He shows the upside for wildlife in the Anthropocene. He does not deny that human beings also cause problems for wildlife, far from it, but he does think we have almost entirely overlooked the gains for wildlife that our presence is also creating.
I have for some time been thinking that while human beings have caused many species extinctions, they must also be causing many speciations. I have not quite had the courage to say so, for fear of being accused by the green thought police of going too far. While watching sparrows on a recent trip to Hawaii, it occurred to me that, though they were little different from the ones I see in London, they must, through isolation, be on the way to becoming a new species of sparrow. Just as a flock of Asian rosefinches shipwrecked on one of the Hawaiian islands six million years ago have turned into scores of species of honeycreeper, half of which are now sadly extinct.
Evolution is driven by new and novel environmental pressures that species adapt to and that drive new species fitting into new environments. That's Humanity in a nutshell. Every ecosystem in the world is more diverse than before man came. In addition man's production of CO2 has generated far more biomass than existed before we came along. Man has had both good and bad affects on the environment and we should never stop trying to mitigate the bad ones but Humanity is part of the environment and Chris Thomas argues that net-net our impact has been to drive a sixth Great Genesis - an explosion of diversity, new species, new life.
It's turning out to be a "good gig".
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