This week evolutionary ecologist Peter Mayhew has presented a set of findings which show the rate of climate change in the Earth to be detrimental to the number of species of animals on our planet. While findings in the past have shown that periods of warmth on our blue globe have also been times when the number of different species of animals has risen, the speed at which the Earth is warming here in the present is, as Mayhew suggests, too rapid for the increase in species to outweigh the number of species that are becoming extinct. The new study Mayhew presents works with a new way of looking at the number of species in each geological period studied with only well-sampled periods rather than with simple tallies of the first and last appearances of each species.
The results of the newest findings here with Peter Mayhew’s group resolve a previous contradiction in the study of climate change in which high and low temperatures both showed growth or decline in numbers of species on the planet. The current article referred to this week “Biodiversity tracks temperature over time” will be appearing in PNAS immediately if not soon, and includes authors P. J. Mayhew, M. A. Bell, T. G. Benton, and A. J. McGowan, who let it be known that with their new findings worked with number of known families of marine invertebrates and sea-surface temperatures over the course of 540 million years.
OF SPECIAL NOTE – Scott Wing, palaeobiologist at the Smithsonian Institution in Washington DC, reacted to the article in a couple ways – the first of which will be important to those of you looking for information on what this all has to do with us humans:
“This article has nothing to say about the effects of global warming at any timescale of interest to most humans.” – Wing
So keep that in mind – you can certainly take what you want from it, but note that the paper does not comment on the effect climate change is having on humans – that’s a talk for a different day.
What findings in this study do show is that when temperatures were high in the history of our planet, biodiversity was high, and when temperatures were low, biodiversity was low as well. These findings, as the group make clear, contradict previous work (that includes work by Mayhew’s group, amongst others), which showed temperature to have the opposite effect on biodiversity.
The rate at which the planet gets warmer or cooler, the group reports, has a direct effect on the biodiversity of the planet. The rate of change can have giant effects on how biodiversity is affected. With the rate of extinctions that are occurring at the rapid change in temperature we’re in now, for example, diversity will likely not rise fast enough to make up for the loss.
Professor Tim Benton, Biological Sciences at the University of Leeds, reacted to this particular possibility according to U of York:
“Science progresses by constantly re-examining conclusions in the light of better data. Our results seem to show that temperature improves biodiversity through time as well as across space. However, they do not suggest that current global warming is good for existing species. Increases in global diversity take millions of years, and in the meantime we expect extinctions to occur.” – Benton
Mayhew adds that the next step is to study longer periods of time, and as Shanan Peters, palaeobiologist at the University of Wisconsin-Madison, notes: the more interesting study in the future will be findings on major climate transitions, like the one we’re very possibly in right this minute.
“The time periods we’re really interested in now are decades and hundreds of years — at maximum 1,000 years. … You can’t get that kind of detail by looking into the deep past. If you want to know how temperature change is affecting things on that timescale, you’re going to have to look at the more recent fossil record.” – Mayhew
*EDITORS NERD NOTE: Though it would be ironic beyond comprehension if it were true, the ecologist Peter Mayhew and the actor Peter Mayhew are not one in the same. SlashGear awards 5 bonus nerd points to anyone who knows Peter Mayhew’s most famous and iconic role without looking it up!