TY - JOUR
T1 - Pulsed evolution shaped modern vertebrate body sizes
AU - Landis, Michael J.
AU - Schraiber, Joshua G.
N1 - Funding Information:
ACKNOWLEDGMENTS. We thank Damien Wilburn, Tracy Heath, and Ignacio Quintero for helpful comments on an early version of this manuscript. Jonathan Chang, Peter Cowman, and Nathan Upham provided invaluable advice on constructing the empirical datasets. Discussions with Joe Felsenstein helped direct the early course of this project. The comments of two anonymous reviewers greatly improved the clarity and readability of the manuscript. J.G.S. was supported in the early stages of this work by National Science Foundation (NSF) Postdoctoral Fellowship DBI-1402120 and subsequently by startup funds from Temple University. M.J.L. was supported initially by the Donnelley Fellowship through the Yale Institute of Biospheric Studies and later through NSF Postdoctoral Fellowship DBI-1612153. Analyses were performed on the Yale High-Performance Computing clusters.
Funding Information:
We thank Damien Wilburn, Tracy Heath, and Ignacio Quintero for helpful comments on an early version of this manuscript. Jonathan Chang, Peter Cowman, and Nathan Upham provided invaluable advice on constructing the empirical datasets. Discussions with Joe Felsenstein helped direct the early course of this project. The comments of two anonymous reviewers greatly improved the clarity and readability of the manuscript. J.G.S. was supported in the early stages of this work by National Science Foundation (NSF) Postdoctoral Fellowship DBI-1402120 and subsequently by startup funds from Temple University. M.J.L. was supported initially by the Donnelley Fellowship through the Yale Institute of Biospheric Studies and later through NSF Postdoctoral Fellowship DBI-1612153. Analyses were performed on the Yale High-Performance Computing clusters.
PY - 2017/12/12
Y1 - 2017/12/12
N2 - The relative importance of different modes of evolution in shaping phenotypic diversity remains a hotly debated question. Fossil data suggest that stasis may be a common mode of evolution, while modern data suggest some lineages experience very fast rates of evolution. One way to reconcile these observations is to imagine that evolution proceeds in pulses, rather than in increments, on geological timescales. To test this hypothesis, we developed a maximum-likelihood framework for fitting Lévy processes to comparative morphological data. This class of stochastic processes includes both an incremental and a pulsed component. We found that a plurality of modern vertebrate clades examined are best fitted by pulsed processes over models of incremental change, stationarity, and adaptive radiation. When we compare our results to theoretical expectations of the rate and speed of regime shifts for models that detail fitness landscape dynamics, we find that our quantitative results are broadly compatible with both microevolutionary models and observations from the fossil record.
AB - The relative importance of different modes of evolution in shaping phenotypic diversity remains a hotly debated question. Fossil data suggest that stasis may be a common mode of evolution, while modern data suggest some lineages experience very fast rates of evolution. One way to reconcile these observations is to imagine that evolution proceeds in pulses, rather than in increments, on geological timescales. To test this hypothesis, we developed a maximum-likelihood framework for fitting Lévy processes to comparative morphological data. This class of stochastic processes includes both an incremental and a pulsed component. We found that a plurality of modern vertebrate clades examined are best fitted by pulsed processes over models of incremental change, stationarity, and adaptive radiation. When we compare our results to theoretical expectations of the rate and speed of regime shifts for models that detail fitness landscape dynamics, we find that our quantitative results are broadly compatible with both microevolutionary models and observations from the fossil record.
KW - Adaptive landscape
KW - Levy process
KW - Macroevolution
KW - Pulsed evolution
UR - http://www.scopus.com/inward/record.url?scp=85038594467&partnerID=8YFLogxK
U2 - 10.1073/pnas.1710920114
DO - 10.1073/pnas.1710920114
M3 - Article
C2 - 29114046
AN - SCOPUS:85038594467
SN - 0027-8424
VL - 114
SP - 13224
EP - 13229
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 50
ER -