A quantitative test of the "Ecomorphotype Hypothesis" for fossil true seals (Family Phocidae).

The fossil record of true seals (Family Phocidae) is mostly made up of isolated bones, some of which are type specimens. Previous studies have sought to increase referral of non-overlapping and unrelated fossils to these taxa using the 'Ecomorphotype Hypothesis', which stipulates that certain differences in morphology between taxa represent adaptations to differing ecology. On this basis, bulk fossil material could be lumped to a specific ecomorphotype, and then referred to species in that ecomorphotype, even if they are different bones.

Charting the course of pinniped evolution: insights from molecular phylogeny and fossil record integration.

Pinnipeds (seals, sea lions, walruses, and their fossil relatives) are one of the most successful mammalian clades to live in the oceans. Despite a well-resolved molecular phylogeny and a global fossil record, a complete understanding of their macroevolutionary dynamics remains hampered by a lack of formal analyses that combine these 2 rich sources of information. We used a meta-analytic approach to infer the most densely sampled pinniped phylogeny to date (36 recent and 93 fossil taxa) and used phylogenetic paleobiological methods to study their diversification dynamics and biogeographic history.

Mutualisms drive plant trait evolution beyond interaction-related traits.

Mutualisms have driven the evolution of extraordinary structures and behavioural traits, but their impact on traits beyond those directly involved in the interaction remains unclear. We addressed this gap using a highly evolutionarily replicated system - epiphytes in the Rubiaceae forming symbioses with ants. We employed models that allow us to test the influence of discrete mutualistic traits on continuous non-mutualistic traits.

Convergence in carnivorous pitcher plants reveals a mechanism for composite trait evolution.

Composite traits involve multiple components that, only when combined, gain a new synergistic function. Thus, how they evolve remains a puzzle. We combined field experiments, microscopy, chemical analyses, and laser Doppler vibrometry with comparative phylogenetic analyses to show that two carnivorous pitcher plant species independently evolved similar adaptations in three distinct traits to acquire a new, composite trapping mechanism.

The dynamic adaptive landscape of cetacean body size.

Adaptive landscapes are central to evolutionary theory, forming a conceptual bridge between micro- and macroevolution. Evolution by natural selection across an adaptive landscape should drive lineages toward fitness peaks, shaping the distribution of phenotypic variation within and among clades over evolutionary timescales. The location and breadth of these peaks in phenotypic space can also evolve, but whether phylogenetic comparative methods can detect such patterns has largely remained unexplored.

Body size, shape and ecology in tetrapods.

Body size and shape play fundamental roles in organismal function and it is expected that animals may possess body proportions that are well-suited to their ecological niche. Tetrapods exhibit a diverse array of body shapes, but to date this diversity in body proportions and its relationship to ecology have not been systematically quantified. Using whole-body skeletal models of 410 extinct and extant tetrapods, we show that allometric relationships vary across individual body segments thereby yielding changes in overall body shape as size increases.

Arboreality constrains morphological evolution but not species diversification in vipers.

An increase in ecological opportunities, either through changes in the environment or acquisition of new traits, is frequently associated with an increase in species and morphological diversification. However, it is possible that certain ecological settings might prevent lineages from diversifying. Arboreality evolved multiple times in vipers, making them ideal organisms for exploring how potentially new ecological opportunities affect their morphology and speciation regimes.

Omnivory in birds is a macroevolutionary sink.

Diet is commonly assumed to affect the evolution of species, but few studies have directly tested its effect at macroevolutionary scales. Here we use Bayesian models of trait-dependent diversification and a comprehensive dietary database of all birds worldwide to assess speciation and extinction dynamics of avian dietary guilds (carnivores, frugivores, granivores, herbivores, insectivores, nectarivores, omnivores and piscivores). Our results suggest that omnivory is associated with higher extinction rates and lower speciation rates than other guilds, and that overall net diversification is negative.