| 1. |
- Heathcote, Robert J P, et al.
(författare)
-
Male behaviour drives assortative reproduction during the initial stage of secondary contact.
- 2016
-
Ingår i: Journal of evolutionary biology. - : Wiley. - 1420-9101 .- 1010-061X. ; 29:5, s. 1003-1015
-
Tidskriftsartikel (refereegranskat)abstract
- Phenotypic divergence in allopatry can facilitate speciation by reducing the likelihood that individuals of different lineages hybridise during secondary contact. However, few studies have established the causes of reproductive isolation in the crucial early stages of secondary contact. Here we establish behavioural causes of assortative reproduction between two phenotypically divergent lineages of the European wall lizard (Podarcis muralis), which have recently come into secondary contact. Parentage was highly assortative in experimental contact zones. However, despite pronounced divergence in male phenotypes, including chemical and visual sexual signals, there was no evidence that females discriminated between males of the two lineages in staged interactions or under naturalistic free-ranging conditions. Instead, assortative reproduction was driven by male mate preferences and, to a lesser extent, male-male competition. The effects were more pronounced when the habitat structure promoted high lizard densities. These results emphasize that assortative reproduction can occur in the absence of female choice, and that male behaviour may play an important role in limiting hybridisation during the initial stages of secondary contact. This article is protected by copyright. All rights reserved.
|
|
| 2. |
- Heathcote, Robert J. P., et al.
(författare)
-
The scent of sun worship: basking experience alters scent mark composition in male lizards
- 2014
-
Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 1432-0762 .- 0340-5443. ; 68:5, s. 861-870
-
Tidskriftsartikel (refereegranskat)abstract
- Signals used in female choice should honestly advertise the benefits that males can provide, with direct benefits often argued as being more important than indirect benefits. However, the nature of direct benefits in species without paternal care or nuptial gifts is poorly understood. Previous studies on lizards suggest that females decide where to settle and assumedly who to mate with based on information contained in scent marks from territorial males. Access to high-quality thermal resources is crucial for female reproductive success. Females may therefore be able to detect and exploit thermal-induced variation in the chemical composition of male scent marks when assessing the quality of his territory. We show that the amount of time male wall lizards (Podarcis muralis) are allowed to bask significantly alters the chemical composition of their femoral secretions used in scent marking. The direction of the change is consistent with adaptive plasticity to maintain signalling efficacy under warm conditions that increase evaporation of femoral secretions. The compounds affected by basking experience included those previously associated with male quality or shown to mediate male-male competition in lizards. However, whilst female lizards could discriminate between scent marks of males that had experienced different basking conditions, they did not preferentially associate with the scent from males from high-quality thermal conditions. These results highlight the potential importance of a previously neglected environmental effect on chemical signalling. We suggest thermal effects may have significant consequences for scent-mark composition in variable environments, with potential repercussions on olfactory communication in lizards.
|
|
| 3. |
- MacGregor, Hannah E A, et al.
(författare)
-
Chemical communication, sexual selection, and introgression in wall lizards
- 2017
-
Ingår i: Evolution. - : Wiley. - 0014-3820. ; 71:10, s. 2327-2343
-
Tidskriftsartikel (refereegranskat)abstract
- Divergence in communication systems should influence the likelihood that individuals from different lineages interbreed, and consequently shape the direction and rate of hybridization. Here, we studied the role of chemical communication in hybridization, and its contribution to asymmetric and sexually selected introgression between two lineages of the common wall lizard (Podarcis muralis). Males of the two lineages differed in the chemical composition of their femoral secretions. Chemical profiles provided information regarding male secondary sexual characters, but the associations were variable and inconsistent between lineages. In experimental contact zones, chemical composition was weakly associated with male reproductive success, and did not predict the likelihood of hybridization. Consistent with these results, introgression of chemical profiles in a natural hybrid zone resembled that of neutral nuclear genetic markers overall, but one compound in particular (tocopherol methyl ether) matched closely the introgression of visual sexual characters. These results imply that associations among male chemical profiles, sexual characters, and reproductive success largely reflect transient and environmentally driven effects, and that genetic divergence in chemical composition is largely neutral. We therefore suggest that femoral secretions in wall lizards primarily provide information about residency and individual identity rather than function as sexual signals.
|
|
