Biology subjects

Menendez, I.

Publications and source records attributed to Menendez, I..

2 recordsLinked to original sources

bioRxiv2022

Evolution along allometric lines of least resistance: Morphological differentiation in Pristurus geckos

Species living in distinct habitats often experience unique ecological selective pressures, which can drive phenotypic divergence. However, how ecophenotypic patterns are affected by allometric trends and trait integration levels is less well understood. Here we evaluate the role of allometry in shaping body size and shape diversity in Pristurus geckos utilizing differing habitats. We found that patterns of body shape allometry and integration were distinct in species with different habitat preferences, with ground-dwelling Pristurus displaying the most divergent allometric trend and the strongest integration. There was also strong concordance between static allometry across individuals and evolutionary allometry among species, revealing that body shape differences among individuals were predictive of evolutionary changes across the phylogeny at macroevolutionary scales. This suggested that phenotypic evolution occurred along allometric lines of least resistance, with allometric trajectories imposing a strong influence on the magnitude and direction of size and shape changes across the phylogeny. When viewed in phylomorphospace, the largest rock-dwelling species were most similar in body shape to the smallest ground-dwelling species, and vice versa. Thus, in Pristurus, phenotypic evolution along the differing habitat-based allometric trajectories resulted in similar body shapes at differing body sizes in distinct ecological habitats.

evolutionary biology↗

bioRxiv2021

Ecological specialization, rather than the island rule, explains morphological diversification in an ancient radiation of geckos

Island colonists are often assumed to experience higher levels of phenotypic diversification than continental taxa. However, empirical evidence has uncovered exceptions to this "island effect". Here, we tested this pattern using the geckos of the genus Pristurus from continental Arabia and Africa and the Socotra Archipelago. Using a recently published phylogeny and an extensive morphological dataset, we explore the differences in phenotypic evolution between Socotran and continental taxa. Moreover, we reconstructed ancestral habitat occupancy to examine if ecological specialisation is correlated with morphological change, comparing phenotypic disparity and trait evolution between habitats. We found a heterogeneous outcome of island colonisation. Namely, only one of the three colonisation events resulted in a body size increase. However, in general, Socotran species do not present higher levels or rates of morphological diversification than continental groups. Instead, habitat specialisation explains better the body size and shape evolution in Pristurus. Particularly, the colonisation of ground habitats appears as the main driver of morphological change, producing the highest disparity and evolutionary rates. Additionally, arboreal species show very similar body size and head proportions. These results reveal a determinant role of ecological mechanisms in morphological evolution and corroborate the complexity of ecomorphological dynamics in continent-island systems.

evolutionary biology↗