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tacosx | 6 years ago

This is a really good read for stats people, this paragraph in particular kind of freaked me out:

> After 100 years of projected extinctions, the global composition of mammals and birds is predicted to shift to smaller (permutation test: body mass observed mean = 70.3 g, body mass projected mean across runs [minimum–maximum across replicates] = 64.1 g [63.4–64.7 g]; P ≤ 0.001), faster-lived (generation length observed mean = 4.27 years, projected mean = 4.22 years [4.21–4.23 years]; P ≤ 0.001), more fecund (litter/clutch size observed mean = 2.51, projected mean = 2.55 [2.54–2.56]; P ≤ 0.001), more generalist (habitat breadth observed mean = 3.23, projected mean = 3.32 [3.31–3.33]; P ≤ 0.001) and more invertivorous species (diet observed mean = −0.00032, projected mean = 0.0012 [0.00087–0.0014]; P ≤ 0.001) (Supplementary Figs. 5f and 7). These shifts are relatively large for the species pool and temporal scale investigated, for example, Davis et al.10 showed that current median mammal body mass is 14% lower than during the Last Interglacial (~130,000 years ago), while we predict an extra 25.2% (23.9–25.8%) reduction in median mammal body mass over the next 100 years from the current level. These declines in body mass equate to a reduction rate of −0.00011% per year between the Last Interglacial and now, compared to a predicted reduction rate of −0.25% (−0.24 to −0.26%) per year between now and the next 100 years.

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