Advanced

Species delimitation and the partitioning of genetic diversity - an example from the Carex flava complex (Cyperaceae)

Hedrén, Mikael LU (2004) In Biodiversity and Conservation 13(2). p.293-316
Abstract
The Carex flava complex ( Cyperaceae) was used as a model system in a study of the effects of variation in species delimitation on genetic diversity estimates. The whole complex constitutes a syngameon within which gene flow may occur between taxa. Several more or less distinct evolutionary lineages in the complex are morphologically similar to each other and are often combined into broadly defined taxonomic species. Separate calculations of genetic diversity estimates for the most narrowly defined species revealed clear differences between some of the taxa; for instance, C. flava s. s. had a very low value for individual gene diversity, H-1 whereas C. hostiana and C. lepidocarpa ssp. lepidocarpa had high values for total genetic... (More)
The Carex flava complex ( Cyperaceae) was used as a model system in a study of the effects of variation in species delimitation on genetic diversity estimates. The whole complex constitutes a syngameon within which gene flow may occur between taxa. Several more or less distinct evolutionary lineages in the complex are morphologically similar to each other and are often combined into broadly defined taxonomic species. Separate calculations of genetic diversity estimates for the most narrowly defined species revealed clear differences between some of the taxa; for instance, C. flava s. s. had a very low value for individual gene diversity, H-1 whereas C. hostiana and C. lepidocarpa ssp. lepidocarpa had high values for total genetic diversity, H-T Amounts of genetic diversity at different hierarchic levels ( H-T, H-S, H-I) generally increased as narrowly defined species were combined into more broadly defined species. However, combining ecological species ( ecotypes) within C. oederi s. l. had little effect on estimates of genetic diversity. The proportion of genetic diversity due to variation between populations, G(ST), increased initially as ecologically and/ or geographically separated lineages were amalgamated, but decreased as the species were even more boradly circumscribed to include distinct lineages growing in mixed populations. The proportion of genetic diversity due to variation between individuals within populations ( numerically equivalent to the inbreeding coefficient, F-IS) was dependent on the degree of hybridization and introgression at sites with mixed populations and was found to increase or decrease when taxa became more broadly circumscribed. It is concluded that differences in species circumscription may have dramatic effects on genetic diversity estimates, and it is recommended that calculations should be performed separately for separate evolutionary lineages in order to obtain comparable estimates for different plant groups. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Biodiversity and Conservation
volume
13
issue
2
pages
293 - 316
publisher
Springer
external identifiers
  • wos:000186971400002
  • scopus:0742323173
ISSN
0960-3115
DOI
10.1023/B:BIOC.0000006499.20169.f9
language
English
LU publication?
yes
id
a9d1f398-917b-44a4-a7ba-71ff27d72273 (old id 137585)
date added to LUP
2007-07-02 10:37:34
date last changed
2017-01-01 04:39:32
@article{a9d1f398-917b-44a4-a7ba-71ff27d72273,
  abstract     = {The Carex flava complex ( Cyperaceae) was used as a model system in a study of the effects of variation in species delimitation on genetic diversity estimates. The whole complex constitutes a syngameon within which gene flow may occur between taxa. Several more or less distinct evolutionary lineages in the complex are morphologically similar to each other and are often combined into broadly defined taxonomic species. Separate calculations of genetic diversity estimates for the most narrowly defined species revealed clear differences between some of the taxa; for instance, C. flava s. s. had a very low value for individual gene diversity, H-1 whereas C. hostiana and C. lepidocarpa ssp. lepidocarpa had high values for total genetic diversity, H-T Amounts of genetic diversity at different hierarchic levels ( H-T, H-S, H-I) generally increased as narrowly defined species were combined into more broadly defined species. However, combining ecological species ( ecotypes) within C. oederi s. l. had little effect on estimates of genetic diversity. The proportion of genetic diversity due to variation between populations, G(ST), increased initially as ecologically and/ or geographically separated lineages were amalgamated, but decreased as the species were even more boradly circumscribed to include distinct lineages growing in mixed populations. The proportion of genetic diversity due to variation between individuals within populations ( numerically equivalent to the inbreeding coefficient, F-IS) was dependent on the degree of hybridization and introgression at sites with mixed populations and was found to increase or decrease when taxa became more broadly circumscribed. It is concluded that differences in species circumscription may have dramatic effects on genetic diversity estimates, and it is recommended that calculations should be performed separately for separate evolutionary lineages in order to obtain comparable estimates for different plant groups.},
  author       = {Hedrén, Mikael},
  issn         = {0960-3115},
  language     = {eng},
  number       = {2},
  pages        = {293--316},
  publisher    = {Springer},
  series       = {Biodiversity and Conservation},
  title        = {Species delimitation and the partitioning of genetic diversity - an example from the Carex flava complex (Cyperaceae)},
  url          = {http://dx.doi.org/10.1023/B:BIOC.0000006499.20169.f9},
  volume       = {13},
  year         = {2004},
}