A portrait of 31-year-old Charles Darwin.

The aim of the Research Networking Programme Frontiers of Speciation Research (FroSpects) is to facilitate bridge-building between disparate approaches to speciation research, by bringing together young and senior European speciation scientists around a number of conferences, workshops, symposia, and schools. A major promise of the Programme is to strengthen Europe’s position in speciation research through the cross-fertilization and integration of empirical and theoretical approaches.

The European Research Networking Programme Frontiers of Speciation Research is funded through the European Science Foundation. The running period is for five years from 2008 to 2013.

In his notebook, Charles Darwin drafted the fundamentals of his theory of evolution in simple drawings.

The traditional view of speciation, proposed as part of the Modern Synthesis, rests on the assumption of geographical isolation. After a population has become subdivided by external causes – like fragmentation due to environmental change or colonization of a new, disconnected habitat – and after the resulting sub-populations have remained separated for sufficiently long, genetic drift and pleiotropic effects of local adaptation are supposed to lead to partial reproductive incompatibility. When the two incipient species get into secondary contact, individuals from one species cannot mate with those of the other or, if mating is still possible, their hybrid offspring are inferior. Further evolution of pre-mating isolation (like assortative mate choice or seasonal isolation) and/or post-mating isolation (like gametic incompatibility) eventually ensures that the two species continue to steer separate evolutionary courses. The trigger for speciation in this process is geographical isolation. It is for this reason that the distinction between allopatric speciation (dependent upon geographical isolation) and sympatric speciation (without geographical isolation) has taken centre stage in the speciation debate. Various other notions of speciation have been suggested in the literature including competitive speciation, ecological speciation, and adaptive speciation. Assessing the relative importance of these alternatives modes of speciation remains an open question of tremendous interest. This problem lies right at the heart of biodiversity science, as the various types of speciation process outlined above differ in many critical assumptions and predictions, often providing different answers to questions such as the following:

• What timescales are expected for speciation? Which empirically observable phases can be distinguished? What is the likelihood for finding species pairs in any of these phases?
• What are the biogeographical premises and implications of speciation? When is spatial segregation between newly formed species expected as cause or consequence of the speciation process? What is the evolutionary origin and significance of hybrid zones?
• Is speciation a one-way road or is its reversal also a common evolutionary phenomenon? What consequences does it have for genome evolution?
• Which types of interactions are involved in speciation processes? Are ecological interactions between conspecifics more important than sexual interactions between mating partners, or vice versa? In addition to intraspecific competition, what are the roles played by interspecific interactions like mutualism and exploitation?
• Is prezygotic isolation preceded by postzygotic isolation, or vice versa? What are the roles of hybridization and reinforcement in speciation processes?
• What are the ecological, genetic, and geographical signatures of speciation? What information needs to be collected empirically before past process can be inferred from present pattern?
• What is the interplay between speciation processes and environmental stressors? Must trends in the environment be expected to help or hinder speciation?

The grand challenge in speciation research is to understand the conditions that promote alternative modes of speciation. To meet this challenge, an integrative approach will be required, combining empirical insight with theoretical advances and bringing together developments in ecology, systematics, and genetics. On this basis, methods for interpreting and classifying the early phases of speciation need to be developed, and for each of the alternative speciation modes the importance of spatial structure, genetic architecture, reproductive isolation, mating traits, and ecological characteristics need to be elucidated.