Phylogenetic congruence between Neotropical primates and plants is driven by frugivory.

Seed dispersal benefits plants and frugivores, and potentially drives co-evolution, with consequences to diversification evidenced for, e.g., primates. Evidence for macro-coevolutionary patterns in multi-specific, plant-animal mutualisms is scarce, and the mechanisms driving them remain unexplored. We tested for phylogenetic congruences in primate-plant interactions and showed strong co-phylogenetic signals across Neotropical forests, suggesting that both primates and plants share evolutionary history. Phylogenetic congruence between Platyrrhini and Angiosperms was driven by the most generalist primates, modulated by their functional traits, interacting with a wide-range of Angiosperms. Consistently similar eco-evolutionary dynamics seem to be operating irrespective of local assemblages, since co-phylogenetic signal emerged independently across three Neotropical regions. Our analysis supports the idea that macroevolutionary, coevolved patterns among interacting mutualistic partners are driven by super-generalist taxa. Trait convergence among multiple partners within multi-specific assemblages appears as a mechanism favouring these likely coevolved outcomes.

Parsing a plethora of pollen: the role of pollen size and shape in the evolution of Boraginaceae.

Pollen, the microgametophyte of seed plants, has an important role in plant reproduction and, therefore, evolution. Pollen is variable in, for example, size, shape, aperture number; these features are particularly diverse in some plant taxa and can be diagnostic. In one family, Boraginaceae, the range of pollen diversity suggests the potential utility of this family as a model for integrative studies of pollen development, evolution and molecular biology. In the present study, a comprehensive survey of the diversity and evolution of pollen from 538 species belonging to 72 genera was made using data from the literature and additional scanning electron microscopy examination. Shifts in diversification rates and the evolution of various quantitative characters were detected, and the results revealed remarkable differences in size, shape and number of apertures. The pollen of one subfamily, Boraginoideae, is larger than that in Cynoglossoideae. The diversity of pollen shapes and aperture numbers in one tribe, Lithospermeae, is greater than that in the other tribes. Ancestral pollen for the family was resolved as small, prolate grains that bear three apertures and are iso-aperturate. Of all the tribes, the greatest number of changes in pollen size and aperture number were observed in Lithospermeae and Boragineae, and the number of apertures was found to be stable throughout all tribes of Cynoglossoideae. In addition, the present study showed that diversification of Boraginaceae cannot be assigned to a single factor, such as pollen size, and the increased rate of diversification for species-rich groups (e.g. Cynoglossum) is not correlated with pollen size or shape evolution. The palynological data and patterns of character evolution presented in the study provide better resolution of the roles of geographical and ecological factors in the diversity and evolution of pollen grains of Boraginaceae, and provide suggestions for future palynological research across the family.

Ecological and evolutionary dynamics of interconnectedness and modularity.

In this contribution, we develop a theoretical framework for linking microprocesses (i.e., population dynamics and evolution through natural selection) with macrophenomena (such as interconnectedness and modularity within an ecological system). This is achieved by developing a measure of interconnectedness for population distributions defined on a trait space (generalizing the notion of modularity on graphs), in combination with an evolution equation for the population distribution. With this contribution, we provide a platform for understanding under what environmental, ecological, and evolutionary conditions ecosystems evolve toward being more or less modular. A major contribution of this work is that we are able to decompose the overall driver of changes at the macro level (such as interconnectedness) into three components: (i) ecologically driven change, (ii) evolutionarily driven change, and (iii) environmentally driven change.

Evidence for soft bounds in Ubuntu package sizes and mammalian body masses.

The development of a complex system depends on the self-coordinated action of a large number of agents, often determining unexpected global behavior. The case of software evolution has great practical importance: knowledge of what is to be considered atypical can guide developers in recognizing and reacting to abnormal behavior. Although the initial framework of a theory of software exists, the current theoretical achievements do not fully capture existing quantitative data or predict future trends. Here we show that two elementary laws describe the evolution of package sizes in a Linux-based operating system: first, relative changes in size follow a random walk with non-Gaussian jumps; second, each size change is bounded by a limit that is dependent on the starting size, an intriguing behavior that we call "soft bound." Our approach is based on data analysis and on a simple theoretical model, which is able to reproduce empirical details without relying on any adjustable parameter and generates definite predictions. The same analysis allows us to formulate and support the hypothesis that a similar mechanism is shaping the distribution of mammalian body sizes, via size-dependent constraints during cladogenesis. Whereas generally accepted approaches struggle to reproduce the large-mass shoulder displayed by the distribution of extant mammalian species, this is a natural consequence of the softly bounded nature of the process. Additionally, the hypothesis that this model is valid has the relevant implication that, contrary to a common assumption, mammalian masses are still evolving, albeit very slowly.