TY - JOUR
T1 - Ant collective behavior is heritable and shaped by selection
AU - Walsh, Justin T.
AU - Garnier, Simon
AU - Linksvayer, Timothy A.
N1 - Funding Information:
Adrian Kase, Ben Cushing, Luigi Pontieri, and Isaac Planas-Sitjà helped design and conduct the behavioral assays. Adrian Kase helped collect and weigh pupae. Rohini Singh and Michael Warner provided invaluable feedback at all stages of the project. Deborah Gordon, Daniel Friedman, and Tali Reiner Brodetzki provided comments on the manuscript that helped improve it. This work was supported by National Science Foundation grant IOS-1452520 awarded to T.A.L.
Publisher Copyright:
© 2020 by The University of Chicago. All rights reserved.
PY - 2020/11/1
Y1 - 2020/11/1
N2 - Collective behaviors are widespread in nature and usually assumed to be strongly shaped by natural selection. However, the degree to which variation in collective behavior is heritable and has fitness consequences—the two prerequisites for evolution by natural selection—is largely unknown. We used a new pharaoh ant (Monomorium pharaonis) mapping population to estimate the heritability, genetic correlations, and fitness consequences of three collective behaviors (foraging, aggression, and exploration), as well as of body size, sex ratio, and caste ratio. Heritability estimates for the collective behaviors were moderate, ranging from 0.17 to 0.32, but lower than our estimates for the heritability of caste ratio, sex ratio, and body size of new workers, queens, and males. Moreover, variation in collective behaviors among colonies was phenotypically correlated, suggesting that selection may shape multiple colony collective behaviors simultaneously. Finally, we found evidence for directional selection that was similar in strength to estimates of selection in natural populations. Altogether, our study begins to elucidate the genetic architecture of collective behavior and is one of the first studies to demonstrate that it is shaped by selection.
AB - Collective behaviors are widespread in nature and usually assumed to be strongly shaped by natural selection. However, the degree to which variation in collective behavior is heritable and has fitness consequences—the two prerequisites for evolution by natural selection—is largely unknown. We used a new pharaoh ant (Monomorium pharaonis) mapping population to estimate the heritability, genetic correlations, and fitness consequences of three collective behaviors (foraging, aggression, and exploration), as well as of body size, sex ratio, and caste ratio. Heritability estimates for the collective behaviors were moderate, ranging from 0.17 to 0.32, but lower than our estimates for the heritability of caste ratio, sex ratio, and body size of new workers, queens, and males. Moreover, variation in collective behaviors among colonies was phenotypically correlated, suggesting that selection may shape multiple colony collective behaviors simultaneously. Finally, we found evidence for directional selection that was similar in strength to estimates of selection in natural populations. Altogether, our study begins to elucidate the genetic architecture of collective behavior and is one of the first studies to demonstrate that it is shaped by selection.
KW - Animal personality
KW - Caste ratio
KW - Collective behavior
KW - Genetic correlation
KW - Heritability
KW - Selection
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U2 - 10.1086/710709
DO - 10.1086/710709
M3 - Article
C2 - 33064586
AN - SCOPUS:85090965962
SN - 0003-0147
VL - 196
SP - 541
EP - 554
JO - American Naturalist
JF - American Naturalist
IS - 5
ER -