Triassic origin and early radiation of multicellular volvocine algae

Matthew D. Herron, Jeremiah Hackett, Frank O. Aylward, Richard E Michod

Research output: Contribution to journalArticle

137 Citations (Scopus)

Abstract

Evolutionary transitions in individuality (ETIs) underlie the watershed events in the history of life on Earth, including the origins of cells, eukaryotes, plants, animals, and fungi. Each of these events constitutes an increase in the level of complexity, as groups of individuals become individuals in their own right. Among the best-studied ETIs is the origin of multicellularity in the green alga Volvox, a model system for the evolution of multicellularity and cellular differentiation. Since its divergence from unicellular ancestors, Volvox has evolved into a highly integrated multicellular organism with cellular specialization, a complex developmental program, and a high degree of coordination among cells. Remarkably, all of these changes were previously thought to have occurred in the last 50-75 million years. Here we estimate divergence times using a multigene data set with multiple fossil calibrations and use these estimates to infer the times of developmental changes relevant to the evolution of multicellularity. Our results show that Volvox diverged from unicellular ancestors at least 200 million years ago. Two key innovations resulting from an early cycle of cooperation, conflict and conflict mediation led to a rapid integration and radiation of multicellular forms in this group. This is the only ETI for which a detailed timeline has been established, but multilevel selection theory predicts that similar changes must have occurred during other ETIs.

Original languageEnglish (US)
Pages (from-to)3254-3258
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume106
Issue number9
DOIs
StatePublished - Mar 3 2009

Fingerprint

Volvox
Individuality
Radiation
Chlorophyta
Plant Cells
Eukaryota
Calibration
Fungi
History
Conflict (Psychology)

Keywords

  • Evolution
  • Multicellularity
  • Multilevel selection
  • Transitions in individuality
  • Volvox

ASJC Scopus subject areas

  • General

Cite this

Triassic origin and early radiation of multicellular volvocine algae. / Herron, Matthew D.; Hackett, Jeremiah; Aylward, Frank O.; Michod, Richard E.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 106, No. 9, 03.03.2009, p. 3254-3258.

Research output: Contribution to journalArticle

@article{59e70ee513054eaa90ffca3eecfdd9ab,
title = "Triassic origin and early radiation of multicellular volvocine algae",
abstract = "Evolutionary transitions in individuality (ETIs) underlie the watershed events in the history of life on Earth, including the origins of cells, eukaryotes, plants, animals, and fungi. Each of these events constitutes an increase in the level of complexity, as groups of individuals become individuals in their own right. Among the best-studied ETIs is the origin of multicellularity in the green alga Volvox, a model system for the evolution of multicellularity and cellular differentiation. Since its divergence from unicellular ancestors, Volvox has evolved into a highly integrated multicellular organism with cellular specialization, a complex developmental program, and a high degree of coordination among cells. Remarkably, all of these changes were previously thought to have occurred in the last 50-75 million years. Here we estimate divergence times using a multigene data set with multiple fossil calibrations and use these estimates to infer the times of developmental changes relevant to the evolution of multicellularity. Our results show that Volvox diverged from unicellular ancestors at least 200 million years ago. Two key innovations resulting from an early cycle of cooperation, conflict and conflict mediation led to a rapid integration and radiation of multicellular forms in this group. This is the only ETI for which a detailed timeline has been established, but multilevel selection theory predicts that similar changes must have occurred during other ETIs.",
keywords = "Evolution, Multicellularity, Multilevel selection, Transitions in individuality, Volvox",
author = "Herron, {Matthew D.} and Jeremiah Hackett and Aylward, {Frank O.} and Michod, {Richard E}",
year = "2009",
month = "3",
day = "3",
doi = "10.1073/pnas.0811205106",
language = "English (US)",
volume = "106",
pages = "3254--3258",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "9",

}

TY - JOUR

T1 - Triassic origin and early radiation of multicellular volvocine algae

AU - Herron, Matthew D.

AU - Hackett, Jeremiah

AU - Aylward, Frank O.

AU - Michod, Richard E

PY - 2009/3/3

Y1 - 2009/3/3

N2 - Evolutionary transitions in individuality (ETIs) underlie the watershed events in the history of life on Earth, including the origins of cells, eukaryotes, plants, animals, and fungi. Each of these events constitutes an increase in the level of complexity, as groups of individuals become individuals in their own right. Among the best-studied ETIs is the origin of multicellularity in the green alga Volvox, a model system for the evolution of multicellularity and cellular differentiation. Since its divergence from unicellular ancestors, Volvox has evolved into a highly integrated multicellular organism with cellular specialization, a complex developmental program, and a high degree of coordination among cells. Remarkably, all of these changes were previously thought to have occurred in the last 50-75 million years. Here we estimate divergence times using a multigene data set with multiple fossil calibrations and use these estimates to infer the times of developmental changes relevant to the evolution of multicellularity. Our results show that Volvox diverged from unicellular ancestors at least 200 million years ago. Two key innovations resulting from an early cycle of cooperation, conflict and conflict mediation led to a rapid integration and radiation of multicellular forms in this group. This is the only ETI for which a detailed timeline has been established, but multilevel selection theory predicts that similar changes must have occurred during other ETIs.

AB - Evolutionary transitions in individuality (ETIs) underlie the watershed events in the history of life on Earth, including the origins of cells, eukaryotes, plants, animals, and fungi. Each of these events constitutes an increase in the level of complexity, as groups of individuals become individuals in their own right. Among the best-studied ETIs is the origin of multicellularity in the green alga Volvox, a model system for the evolution of multicellularity and cellular differentiation. Since its divergence from unicellular ancestors, Volvox has evolved into a highly integrated multicellular organism with cellular specialization, a complex developmental program, and a high degree of coordination among cells. Remarkably, all of these changes were previously thought to have occurred in the last 50-75 million years. Here we estimate divergence times using a multigene data set with multiple fossil calibrations and use these estimates to infer the times of developmental changes relevant to the evolution of multicellularity. Our results show that Volvox diverged from unicellular ancestors at least 200 million years ago. Two key innovations resulting from an early cycle of cooperation, conflict and conflict mediation led to a rapid integration and radiation of multicellular forms in this group. This is the only ETI for which a detailed timeline has been established, but multilevel selection theory predicts that similar changes must have occurred during other ETIs.

KW - Evolution

KW - Multicellularity

KW - Multilevel selection

KW - Transitions in individuality

KW - Volvox

UR - http://www.scopus.com/inward/record.url?scp=62549085232&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=62549085232&partnerID=8YFLogxK

U2 - 10.1073/pnas.0811205106

DO - 10.1073/pnas.0811205106

M3 - Article

VL - 106

SP - 3254

EP - 3258

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

SN - 0027-8424

IS - 9

ER -