John P. DeLong a,b,1, Jordan G. Okie a, Melanie E. Moses a,c, Richard M. Sibly d, and James H. Brown a,e,1
-Author Affiliations
aDepartment of Biology, University of New Mexico, Albuquerque, NM 87131;
bDepartment of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520;
cDepartment of Computer Science, University of New Mexico, Albuquerque, NM 87131;
dSchool of Biological Sciences, University of Reading, Reading RG6 6AS, United Kingdom; and
e Santa Fe Institute, Santa Fe, NM 87501
Contributed by James H. Brown, June 2, 2010 (sent for review May 15, 2010)
Abstract
The diversification of life involved enormous increases in size and complexity. The evolutionary transitions from prokaryotes to unicellular eukaryotes to metazoans were accompanied by major innovations in metabolic design. Here we show that the scalings of metabolic rate, population growth rate, and production efficiency with body size have changed across the evolutionary transitions. Metabolic rate scales with body mass superlinearly in prokaryotes, linearly in protists, and sublinearly in metazoans, so Kleiber’s 3/4 power scaling law does not apply universally across organisms. The scaling of maximum population growth rate shifts from positive in prokaryotes to negative in protists and metazoans, and the efficiency of production declines across these groups. Major changes in metabolic processes during the early evolution of life overcame existing constraints, exploited new opportunities, and imposed new constraints.
energetic constraints production efficiency rmax endosymbiosis multicellularity
Footnotes
1To whom correspondence may be addressed. E-mail: john.delong@yale.eduor jhbrown@unm.edu.
Author contributions: J.P.D., J.G.O., M.E.M., R.M.S., and J.H.B. designed research; performed research; analyzed data; and wrote the paper.
The authors declare no conflict of interest.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1007783107/-/DCSupplemental.
The authors declare no conflict of interest.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1007783107/-/DCSupplemental.
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