Germination behavior is one of the earliest phenotypes expressed by plants. This fact has several consequences for the evolution of postgermination traits, ecological niches, and geographic ranges. By determining the conditions that plants experience after they germinate, germination influences phenotypic expression of postgermination traits, natural selection on them, and their genetic basis. The breadth of germination niches may influence the ecological breadth and geographic ranges of species. Because germination is expressed early, it is frequently subjected to natural selection before other traits are expressed. We review evidence for natural selection on and adaptation of germination and discuss how the breadth of the germination niche is associated with the ecological niche and range of plant species. We review evidence for the coevolution of germination and postgermination traits and compare germination to postgermination niches. Finally, we discuss how germination responses to altered environments can influence species distribution and the evolution of postgermination traits after environmental change.

It is difficult to overstate the cultural and biological impacts that the domestication of plants and animals has had on our species. Fundamental questions regarding where, when, and how many times domestication took place have been of primary interest within a wide range of academic disciplines. Within the last two decades, the advent of new archaeological and genetic techniques has revolutionized our understanding of the pattern and process of domestication and agricultural origins that led to our modern way of life. In the spring of 2011, 25 scholars with a central interest in domestication representing the fields of genetics, archaeobotany, zooarchaeology, geoarchaeology, and archaeology met at the National Evolutionary Synthesis Center to discuss recent domestication research progress and identify challenges for the future. In this introduction to the resulting Special Feature, we present the state of the art in the field by discussing what is known about the spatial and temporal patterns of domestication, and controversies surrounding the speed, intentionality, and evolutionary aspects of the domestication process. We then highlight three key challenges for future research. We conclude by arguing that although recent progress has been impressive, the next decade will yield even more substantial insights not only into how domestication took place, but also when and where it did, and where and why it did not.The domestication of plants and animals was one of the most significant cultural and evolutionary transitions in the ∼200,000-y history of our species. Investigating when, where, and how domestication took place is therefore crucial for understanding the roots of complex societies. Domestication research is equally important to scholars from a wide range of disciplines, from evolutionary biology to sustainability science (1, 2). Research into both the process and spatiotemporal origins of domestication has accelerated significantly over the past decade through archaeological research, advances in DNA/ RNA sequencing technology, and methods used to recover and formally identify changes in interactions among plants and animals leading to domestication (2-4). In the spring of 2011, 25 scholars with a central interest in domestication and representing the fields of genetics, archaeobotany, zooarchaeology, geoarchaeology, and archaeology met at the National Evolutionary Synthesis Center to discuss recent progress in domestication research and identify challenges for the future. Our goal was to begin reconsidering plant and animal domestication within an integrated evolutionary and cultural framework that takes into account not just new genetic and archaeological data, but also ideas related to epigenetics, plasticity, geneby-environment interactions, gene-culture coevolution, and niche construction. Each of these concepts is relevant to understanding phenotypic change, heritability, and selection, and they are all fundamental components of the New Biology (5) and Expanded Modern Evolutionary Synthesis (6).

SummarySeed dormancy, by controlling the timing of germination, can strongly affect plant survival. The kind of seed dormancy, therefore, can influence both population and species-level processes such as colonization, adaptation, speciation, and extinction.We used a dataset comprising over 14 000 taxa in 318 families across the seed plants to test hypotheses on the evolution of different kinds of seed dormancy and their association with lineage diversification.We found morphophysiological dormancy to be the most likely ancestral state of seed plants, suggesting that physiologically regulated dormancy in response to environmental cues was present at the origin of seed plants. Additionally, we found that physiological dormancy (PD), once disassociated from morphological dormancy, acted as an 'evolutionary hub' from which other dormancy classes evolved, and that it was associated with higher rates of lineage diversification via higher speciation rates.The environmental sensitivity provided by dormancy in general, and by PD in particular, appears to be a key trait in the diversification of seed plants.

Aim The olive tree is considered one of the best indicators of the Mediterranean climate. The species' distribution is associated with geographical and bioclimatic factors, as well as being influenced by a long period of cultivation. Despite concerted efforts of different research groups, the origin of the Mediterranean olive tree still remains elusive. In the present study, relationships between taxa and populations covering the entire range of Olea europaea were investigated using both maternal (plastid genome) and biparental (nuclear genome) markers to disclose evolutionary patterns in the olive complex. Phylogenetic and phylogeographical results of the two-genome analyses were interpreted in a biogeographical context.Location Mediterranean, temperate and subtropical floristic regions of the Old World.Methods Phylogeographical reconstructions of plastid DNA polymorphism were performed using microsatellites, restriction sites and indels on a wide sample of 185 representative trees across the Old World, including 28 herbarium specimens from remote areas. Additionally, the potential utility of one ITS-1 pseudogene for phylogenetic analyses was explored using Bayesian and maximum parsimony approaches on a subsample of 38 olive trees.Results Forty plastid haplotypes were recognized and split into two lineages and seven sublineages. The analysis of ITS-1 sequences also allowed the identification of seven well differentiated groups. Distribution of plastid and ribosomal DNA lineages was congruent, but particular cases of phylogenetic incongruence were disclosed (particularly in the Sahara and Madeira). Lastly, two divergent ITS-1 copies were isolated from the same sample of four individuals of different subspecies.Main conclusions Phylogenetic congruence of both ITS-1 and plastid lineages suggested an evolutionary scenario of predominant isolation during the PlioPleistocene in Macaronesia, the Mediterranean, southern Africa, eastern Africa and Asia. The Saharan desert appeared to have played an important role of vicariant barrier between southern and northern African populations in early times. Incongruence of some plastid and nuclear results, as well as intermingled ITS-1 copies of different lineages in single individuals, was interpreted as a result of recurrent reticulation events in the olive complex. We identified an ancient hybrid zone from the Sahara to north-eastern African mountains, where divergent plastid and nuclear lineages still co-exist. Results of this paper, and previous studies, suggest that the cultivated olive originated from a pre-Quaternary Mediterranean ancestor, with no evidence for a recent hybrid origin. In contrast, a continuous process of olive domestication through local hybridization events of cultivated trees with natural populations may have brought about a remarkably high genomic diversity among cultivated trees across the Mediterranean.

656I. 657II. 658III. 660IV. 661V. 663VI. 663VII. 664VIII. 664 665 References 665 Summary Baker's law refers to the tendency for species that establish on islands by long‐distance dispersal to show an increased capacity for self‐fertilization because of the advantage of self‐compatibility when colonizing new habitat. Despite its intuitive appeal and broad empirical support, it has received substantial criticism over the years since it was proclaimed in the 1950s, not least because it seemed to be contradicted by the high frequency of dioecy on islands. Recent theoretical work has again questioned the generality and scope of Baker's law. Here, we attempt to discern where the idea is useful to apply and where it is not. We conclude that several of the perceived problems with Baker's law fall away when a narrower perspective is adopted on how it should be circumscribed. We emphasize that Baker's law should be read in terms of an enrichment of a capacity for uniparental reproduction in colonizing situations, rather than of high selfing rates. We suggest that Baker's law might be tested in four different contexts, which set the breadth of its scope: the colonization of oceanic islands, metapopulation dynamics with recurrent colonization, range expansions with recurrent colonization, and colonization through species invasions.

This study indicates the necessity of revising current taxonomic boundaries in Olea. The results also suggest that main lines of evolution were promoted by major Tertiary climatic shifts: (1) the split between subgenera Olea and Paniculatae appears to have taken place at the Miocene-Oligocene boundary; (2) the separation of sections Ligustroides and Olea may have occurred during the Early Miocene following the Mi-1 glaciation; and (3) the diversification within these sections (and the origin of dense abaxial indumentum in section Olea) was concomitant with the aridification of Africa in the Late Miocene.

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Seed dormancy is expected to provide ecological advantages by adjusting germination to the favorable growth period. However, many species produce nondormant seeds, particularly in wet tropical forests, a biogeographic pattern that is not well accounted for in current models. We hypothesized that the global distribution of dormant seeds derives from their adaptive value in predictably fluctuating (i.e. seasonal) environments. However, the advantage conferred by dormancy might ultimately depend on other seed attributes, particularly size. This general model was tested within a phylogenetically informed framework using a data set comprising > 216 000 world-wide observations of Fabaceae, spanning three orders of magnitude in seed size and including both dormant and nondormant seeds. Our results confirmed our hypothesis: nondormant seeds can only evolve in climates with long growing seasons and/or in lineages that produce larger seeds. Conversely, dormancy should be evolutionarily stable in temperate lineages with small seeds. When the favorable season is fleeting, seed dormancy is the only adaptive strategy. Based on these results, we predict that, within a given lineage, taxa producing larger, nondormant seeds will necessarily predominate in aseasonal environments, while plants bearing small, dormant seeds will be dominant under short growing seasons.