Genetic, socio-ecological and fitness correlates of extra-group paternity in the European badger (Meles meles)
<p>The evolution of extra-group paternity (EGP) is a contentious issue in evolutionary biology. This thesis examines the factors and adaptive benefits driving EGP in a high-density, group-living population of European badgers (<em>Meles meles</em>).</p> <p>To improve po...
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| Format: | Thesis |
| Language: | English |
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2012
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| _version_ | 1797081276366192640 |
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| author | Annavi, G |
| author2 | Macdonald, D |
| author_facet | Macdonald, D Annavi, G |
| author_sort | Annavi, G |
| collection | OXFORD |
| description | <p>The evolution of extra-group paternity (EGP) is a contentious issue in evolutionary biology. This thesis examines the factors and adaptive benefits driving EGP in a high-density, group-living population of European badgers (<em>Meles meles</em>).</p> <p>To improve power to assign parentage, I isolated and characterised 21 new polymorphic microsatellite markers. I genotyped 83% of 1410 badger trapped 1987‒2010 using 35 autosomal microsatellite markers. Maternity and paternity were assigned at 80% confidence ca. 82% of individuals. 48% of paternities were extra-group, where 85% were attributable to neighbouring-group males and EGP was detected in 47% of litters; thus badger social group do not correspond with a breeding unit. </p> <p>I tested whether indirect genetic benefits explain these high EGP rates. <em>(1) ‘Good-gene-as-heterozygosity Hypothesis’:</em> Paternal heterozygosity, but not maternal or an individual’s own heterozygosity, associated positively with first-year survival probability. Under benign environmental conditions, cubs fathered by more heterozygous males had a higher first year survival probability. Despite this correlation, the EGP rate per litter correlated with neither average nor maximum within-group heterozygosity of candidate fathers. <em>(2) Fitness benefit Hypothesis:</em> Extra-group offspring (EGO) had lower first-year survival probability and lived 1.3 years less than within-group offspring (WGO). Female WGO produced more litters and offspring over their lifetime than female EGO, whereas male EGO produced more offspring than male WGO. <em>(3) Inbreeding avoidance hypothesis:</em> The EGP rate within a litter increased with greater average pair-wise relatedness between mothers and within-group candidate fathers. No inbreeding depression on first-year survival probability was detected, but small sample sizes limited statistical power. Socio-ecologically, at the litter level, EGP correlated negatively with the number of within-group candidate fathers, and positively with neighbouring-group candidate fathers. </p> <p>In conclusion, EGP in badgers may reduce inbreeding and be maintained in the population through a sex-specific antagonistic selection and indirect genetic benefits may occur when the total fitness benefits of producing extra-group sons outweigh the costs of producing extra-group daughters. These indirect genetic benefits only partially explain the evolution of promiscuity in European badgers, highlighting that evolutionary factors underlying promiscuity remain unclear. </p> |
| first_indexed | 2024-03-07T01:12:20Z |
| format | Thesis |
| id | oxford-uuid:8d7304b2-84a2-4d5d-bbbc-63270d309e2e |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T01:12:20Z |
| publishDate | 2012 |
| record_format | dspace |
| spelling | oxford-uuid:8d7304b2-84a2-4d5d-bbbc-63270d309e2e2022-03-26T22:51:19ZGenetic, socio-ecological and fitness correlates of extra-group paternity in the European badger (Meles meles)Thesishttp://purl.org/coar/resource_type/c_db06uuid:8d7304b2-84a2-4d5d-bbbc-63270d309e2eEcology (zoology)Zoological sciencesGenetics (life sciences)EnglishOxford University Research Archive - Valet2012Annavi, GMacdonald, D<p>The evolution of extra-group paternity (EGP) is a contentious issue in evolutionary biology. This thesis examines the factors and adaptive benefits driving EGP in a high-density, group-living population of European badgers (<em>Meles meles</em>).</p> <p>To improve power to assign parentage, I isolated and characterised 21 new polymorphic microsatellite markers. I genotyped 83% of 1410 badger trapped 1987‒2010 using 35 autosomal microsatellite markers. Maternity and paternity were assigned at 80% confidence ca. 82% of individuals. 48% of paternities were extra-group, where 85% were attributable to neighbouring-group males and EGP was detected in 47% of litters; thus badger social group do not correspond with a breeding unit. </p> <p>I tested whether indirect genetic benefits explain these high EGP rates. <em>(1) ‘Good-gene-as-heterozygosity Hypothesis’:</em> Paternal heterozygosity, but not maternal or an individual’s own heterozygosity, associated positively with first-year survival probability. Under benign environmental conditions, cubs fathered by more heterozygous males had a higher first year survival probability. Despite this correlation, the EGP rate per litter correlated with neither average nor maximum within-group heterozygosity of candidate fathers. <em>(2) Fitness benefit Hypothesis:</em> Extra-group offspring (EGO) had lower first-year survival probability and lived 1.3 years less than within-group offspring (WGO). Female WGO produced more litters and offspring over their lifetime than female EGO, whereas male EGO produced more offspring than male WGO. <em>(3) Inbreeding avoidance hypothesis:</em> The EGP rate within a litter increased with greater average pair-wise relatedness between mothers and within-group candidate fathers. No inbreeding depression on first-year survival probability was detected, but small sample sizes limited statistical power. Socio-ecologically, at the litter level, EGP correlated negatively with the number of within-group candidate fathers, and positively with neighbouring-group candidate fathers. </p> <p>In conclusion, EGP in badgers may reduce inbreeding and be maintained in the population through a sex-specific antagonistic selection and indirect genetic benefits may occur when the total fitness benefits of producing extra-group sons outweigh the costs of producing extra-group daughters. These indirect genetic benefits only partially explain the evolution of promiscuity in European badgers, highlighting that evolutionary factors underlying promiscuity remain unclear. </p> |
| spellingShingle | Ecology (zoology) Zoological sciences Genetics (life sciences) Annavi, G Genetic, socio-ecological and fitness correlates of extra-group paternity in the European badger (Meles meles) |
| title | Genetic, socio-ecological and fitness correlates of extra-group paternity in the European badger (Meles meles) |
| title_full | Genetic, socio-ecological and fitness correlates of extra-group paternity in the European badger (Meles meles) |
| title_fullStr | Genetic, socio-ecological and fitness correlates of extra-group paternity in the European badger (Meles meles) |
| title_full_unstemmed | Genetic, socio-ecological and fitness correlates of extra-group paternity in the European badger (Meles meles) |
| title_short | Genetic, socio-ecological and fitness correlates of extra-group paternity in the European badger (Meles meles) |
| title_sort | genetic socio ecological and fitness correlates of extra group paternity in the european badger meles meles |
| topic | Ecology (zoology) Zoological sciences Genetics (life sciences) |
| work_keys_str_mv | AT annavig geneticsocioecologicalandfitnesscorrelatesofextragrouppaternityintheeuropeanbadgermelesmeles |