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Modeling the Population-Level Processes of Biodiversity Gain and Loss at Geological Timescales.

Authors :
Fortelius M
Geritz S
Gyllenberg M
Raia P
Toivonen J
Source :
The American naturalist [Am Nat] 2015 Dec; Vol. 186 (6), pp. 742-54. Date of Electronic Publication: 2015 Oct 09.
Publication Year :
2015

Abstract

The path of species diversification is commonly observed by inspecting the fossil record. Yet, how species diversity changes at geological timescales relate to lower-level processes remains poorly understood. Here we use mathematical models of spatially structured populations to show that natural selection and gradual environmental change give rise to discontinuous phenotype changes that can be connected to speciation and extinction at the macroevolutionary level. In our model, new phenotypes arise in the middle of the environmental gradient, while newly appearing environments are filled by existing phenotypes shifting their adaptive optima. Slow environmental change leads to loss of phenotypes in the middle of the extant environmental range, whereas fast change causes extinction at one extreme of the environmental range. We compared our model predictions against a well-known yet partially unexplained pattern of intense hoofed mammal diversification associated with grassland expansion during the Late Miocene. We additionally used the model outcomes to cast new insight into Cope's law of the unspecialized. Our general finding is that the rate of environmental change determines where generation and loss of diversity occur in the phenotypic and physical spaces.

Details

Language :
English
ISSN :
1537-5323
Volume :
186
Issue :
6
Database :
MEDLINE
Journal :
The American naturalist
Publication Type :
Academic Journal
Accession number :
26655981
Full Text :
https://doi.org/10.1086/683660