BRANTA — Sepand Riyahi
Local adaptation by birds to human-altered habitats: the Great Tit and the House Sparrow as model species
Institution: University of Barcelona, Spain
Supervisors: Juan Carlos Senar
Details: PhD, 2017
Subject Keywords: Species Keywords: house sparrow Passer domesticus, great tit Parus major
Human-altered environments have expanded rapidly in the past decades and made a huge impact on living organisms. Inhabiting in such a habitat can modify different traits in animals, allowing for a better adaptation to these human-altered environments. In the first part of this thesis I investigated patterns of recent (contemporary) adaptation to urban habitats, focusing on the role of behavioural, genetic and epigenetic variation in great tits. In the second part of the thesis I investigated patterns of adaptation to human-made habitats in a larger time-scale, focusing on the origin and expansion of the house sparrow, which has been for ages a human commensalism. I additionally checked the effect of methylation variation on the rapid expansion and high phenotypic variation of house sparrow in the Palearctic region. Regarding the great tit I found that urban-dwelling birds are more explorative in novel environments and bolder in front of new objects than forest individuals. I found several epigenetic modifications and genetic polymorphisms possibly related to novelty seeking behaviour in the great tits. Our results suggested that epigenetics adjustment can be different in the urban-dwelling great tits in comparison to the forest birds. Furthermore, we investigated the possible polymorphisms in the Melanocortin-1 gene in the great tit to relate it with the size of the black belly stripe, which had previously been found to differ between urban and forest individuals.
However, results showed that there is no polymorphism in this gene in relation to the size of the black belly stripe. In relation to the house sparrow, we found that the commensalism of this species with humans has a single origin and probably initiated in the Middle East. Then, it expanded rapidly in the Palearctic region with the aid of agriculture and human civilizations expansion. In addition, we discovered that the genome-wide methylation pattern of house sparrows has a general stability within five subspecies in the Middle East but we found high level of variation at the individual level within populations which likely happened randomly rather than due to selection.
Riyahi S., Vilatersana R., Ghorbani H., Aliabadian M. & Senar J.C. 2017. Natural epigenetic variation within and among six subspecies of the house sparrow Passer domesticus, Journal of Experimental Biology, 220: 4016-4023. doi:10.1242/jeb.169268
Riyahi S., Björklund M., F. Mateos-Gonzalez & Senar J.C. 2017. Personality differentiation in the urban habitat: behavioural and DRD4 polymorphisms in the great tits (Parus major) of Barcelona city, Journal of Ethology,1-8. doi:10.1007/s10164-016-0496-2
Riyahi S., Delgado, M. S., Calafell, F., Monk, D., & Senar, J. C. 2015. Combined epigenetic and intraspecific variation of the DRD4 and SERT genes influence novelty seeking behavior in great tit Parus major. Epigenetics, 10:6,516-525. doi:10.1080/15592294.2015.1046027
Riyahi S., Bjorklund M., Odeen A. & Senar J.C. 2014. No association between the melanocortin-1 receptor (MC1R) and black belly stripe size variation in the great tit Parus major. Bird Study, 1-3. doi:10.1080/00063657.2014.988601
Saetre, G. P.*, Riyahi, S.*, Aliabadian, M., Hermansen, J. S., Hogner, S.,Olsson, U. & Elgvin, T. O. (*equal contribution). 2012. Single origin of human commensalism in the house sparrow. Journal of Evolutionary Biology, 25:788-796. doi: 10.1111/j.1420-9101.2012.02470.x