MBE Advance Access originally published online on March 9, 2005
Molecular Biology and Evolution 2005 22(6):1393-1402; doi:10.1093/molbev/msi133
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sociality and the Rate of Molecular Evolution
,
* Centre for the Study of Evolution, School of Life Sciences, University of Sussex, Brighton, United Kingdom; Department of Zoology and Entomology, University of Queensland, Brisbane, Australia; Evolutionary Biology Unit, South Australian Museum, Adelaide; and Adelaide University, South Australia, Australia
E-mail: l.d.bromham{at}sussex.ac.uk.
The molecular clock does not tick at a uniform rate in all taxa but may be influenced by species characteristics. Eusocial species (those with reproductive division of labor) have been predicted to have faster rates of molecular evolution than their nonsocial relatives because of greatly reduced effective population size; if most individuals in a population are nonreproductive and only one or few queens produce all the offspring, then eusocial animals could have much lower effective population sizes than their solitary relatives, which should increase the rate of substitution of "nearly neutral" mutations. An earlier study reported faster rates in eusocial honeybees and vespid wasps but failed to correct for phylogenetic nonindependence or to distinguish between potential causes of rate variation. Because sociality has evolved independently in many different lineages, it is possible to conduct a more wide-ranging study to test the generality of the relationship. We have conducted a comparative analysis of 25 phylogenetically independent pairs of social lineages and their nonsocial relatives, including bees, wasps, ants, termites, shrimps, and mole rats, using a range of available DNA sequences (mitochondrial and nuclear DNA coding for proteins and RNAs, and nontranslated sequences). By including a wide range of social taxa, we were able to test whether there is a general influence of sociality on rates of molecular evolution and to test specific predictions of the hypothesis: (1) that social species have faster rates because they have reduced effective population sizes; (2) that mitochondrial genes would show a greater effect of sociality than nuclear genes; and (3) that rates of molecular evolution should be correlated with the degree of sociality. We find no consistent pattern in rates of molecular evolution between social and nonsocial lineages and no evidence that mitochondrial genes show faster rates in social taxa. However, we show that the most highly eusocial Hymenoptera do have faster rates than their nonsocial relatives. We also find that social parasites (that utilize the workers from related species to produce their own offspring) have faster rates than their social relatives, which is consistent with an effect of lower effective population size on rate of molecular evolution. Our results illustrate the importance of allowing for phylogenetic nonindependence when conducting investigations of determinants of variation in rate of molecular evolution.
Key Words: eusocial • substitution rate • nearly neutral theory • molecular clock • effective population size • comparative method
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  C. Tsantes and M. E. Steiper Age at first reproduction explains rate variation in the strepsirrhine molecular clock PNAS, October 27, 2009; 106(43): 18165 - 18170. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Viljakainen, J. D. Evans, M. Hasselmann, O. Rueppell, S. Tingek, and P. Pamilo Rapid Evolution of Immune Proteins in Social Insects Mol. Biol. Evol., August 1, 2009; 26(8): 1791 - 1801. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Bromham Why do species vary in their rate of molecular evolution? Biol Lett, June 23, 2009; 5(3): 401 - 404. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Charlesworth and A. Eyre-Walker The other side of the nearly neutral theory, evidence of slightly advantageous back-mutations PNAS, October 23, 2007; 104(43): 16992 - 16997. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Pamilo, L. Viljakainen, and A. Vihavainen Exceptionally High Density of NUMTs in the Honeybee Genome Mol. Biol. Evol., June 1, 2007; 24(6): 1340 - 1346. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Thomas, J. J. Welch, M. Woolfit, and L. Bromham There is no universal molecular clock for invertebrates, but rate variation does not scale with body size PNAS, May 9, 2006; 103(19): 7366 - 7371. [Abstract] [Full Text] [PDF]
|
|