Title: | Evolution of reproductive isolation in sympatric Arctic charr morphs (Salvelinus alpinus) |
Author: | |
Advisor: | Kalina H. Kapralova, Sigurður S. Snorrason |
Date: | 2022-06 |
Language: | English |
University/Institute: | Háskóli Íslands University of Iceland |
School: | Verkfræði- og náttúruvísindasvið (HÍ) School of Engineering and Natural Sciences (UI) |
Department: | Líf- og umhverfisvísindadeild (HÍ) Faculty of Life and Environmental Sciences (UI) |
ISBN: | 978-9935-9647-5-5 |
Subject: | Líffræði; Doktorsritgerðir |
URI: | https://hdl.handle.net/20.500.11815/3259 |
Citation:Quentin Jean-Baptiste Horta-Lacueva, 2022, Evolution of reproductive isolation in sympatric Arctic charr morphs , PhD dissertation, Faculty of Life and Environmental Sciences, University of Iceland, 187 pp.
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Abstract:The theory of divergence by trophic polymorphism, an important part of diversification in
vertebrates, has recently been extended to encompass the interplay of developmental,
ecological and evolutionary processes (Eco-Evo-Devo dynamics). However, this extended
theory doesn’t thoroughly explain the evolution of reproductive isolation, which is
unfortunate considering the recent advances from the field of speciation. In this thesis, I
argue that the Arctic charr morphs of Thingvallavatn are an ideal system to study how
reproductive isolation is embedded within the theory of divergence by resource
polymorphism, which I present through five papers. First, I focused on two sympatric
morphs, the small-benthic (SB) and the planktivorous (PL) charr. Common-garden
experiments showed limited evidence for hybridization to affect the structure of trait
covariance in both morphs, regarding morphology, developmental timing and feeding
behaviour (Paper I), and personality traits (Paper II). However, information on gene
expression variability in embryos indicated that hybridization might influence evolvability
(Paper III). Multiple reproductive barriers between the two morphs, involving habitat use,
assortative mating and hybrid development were also assessed (Paper IV). Finally, Paper V
combines field studies and rearing experiments to explore the interplay between habitat
choice and offspring development in the large-benthic (LB) charr, which spawns earlier in
the season than the other morphs. The results suggested that LB-charr favour temperature
conditions that may delay offspring development. Altogether, these findings provide an
overview on reproductive isolation among the Arctic charr morphs of Thingvallavatn and
constitute a primer to study speciation in an Eco-Evo-Devo context.
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