Correlations between sex rate estimates and fitness across predominantly parthenogenetic flatworm populations.
J Evol Biol
; 21(1): 276-286, 2008 Jan.
Article
em En
| MEDLINE
| ID: mdl-17995947
ABSTRACT
One explanation for the success of sexual reproduction is that sex increases the efficacy of natural selection. Recombination and segregation lead to fitness variance among offspring which then offers a wider target for natural selection. Consequently, adaptation to changing environments is accelerated and population mean fitness will increase. We investigated whether low levels of sex are associated with increased fitness variance and mean in parthenogenetic biotypes of the planarian flatworm Schmidtea polychroa. Parthenogenetic S. polychroa are triploid and reproduce clonally with occasional sexual reproduction. By-products and measures of occasional sex are the local presence of tetraploids and elevated levels of genotypic diversity. We correlated the proportion of tetraploids and genotypic diversity with fitness attributes of six genetically differentiated locations within one meta-population. Results indicate strong, positive correlations with variance and with mean offspring number produced during a 5-week period. The ecological and evolutionary implications for the maintenance of parthenogenetic S. polychroa are discussed.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Planárias
/
Recombinação Genética
/
Fertilização
Limite:
Animals
Idioma:
En
Revista:
J Evol Biol
Assunto da revista:
BIOLOGIA
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Alemanha