We assess the degree to which adaptation to a uniform environment among independently evolving asexual populations is associated with increasing divergence of those populations. In addition, we are...

In so far as it is associated with declining fertility and increasing mortality, senescence is directly detrimental to reproductive success. Natural selection should therefore act in the direction of postponing or eliminating senescence from the life history. The widespread occurrence of senescence is explained by observing that (i) the force of natural selection is generally weaker at late ages than at early ages, and (ii) the acquisition of greater longevity usually involves some cost. Two convergent theories are the ‘antagonistic pleiotropy’ theory, based in population genetics, and the ‘disposable soma’ theory, based in physiological ecology. The antagonistic pleiotropy theory proposes that certain alleles that are favoured because of beneficial early effects also have deleterious later effects. The disposable soma theory suggests that because of the competing demands of reproduction less effort is invested in the maintenance of somatic tissues than is necessary for indefinite survival.

The transformative research approach of Real-World Laboratories (RWL) has recently attracted attention in German sustainability science. Some definitions and understandings have been published, but guidelines and procedural quality criteria for establishing and running a RWL are still missing. To address this gap, this article has two aims. First, it aims to derive key components of RWLs from the current discourse on RWLs and similar, but more elaborated research approaches. Second, it aims to transfer these key components into a comprehensive research practice. This practice is illustrated by the RWL process in the project “Well-being Transformation Wuppertal” (WTW). Methodologically, the article builds on a review of RWL-related approaches for collaborative, intervention-oriented research. This includes transition management, transdisciplinary process models and action research. Based on this review, eight key components for RWLs are proposed. They position RWLs as a normatively framed approach that aims to contribute to local action for sustainable development and the empowerment of change agents. The approach uses transdisciplinary methods of knowledge integration and engages in cyclical real-world interventions within certain spatial and content-related boundaries. The components are transferred into a flowchart, detailing process steps, aims, responsibilities and overall principles for putting RWLs into practice. Thus, a hitherto missing tool for designing and running RWLs is provided. Then, the RWL in the district of Mirke, Wuppertal, is used as an empirical example to illustrate the application of the flowchart and related key components. Consecutive discussions centre on the different roles of researchers and practitioners in the research process, as well as the relevance of an underlying theory of change for effective interventions. Finally, critical reflection, application and amendment of the proposed flowchart are encouraged.

Growing recognition that much of the evolutionary history of eukaryotic genomes reflects the operation of turnover processes involving repetitive DNA sequences has led to the recent formulation of models describing speciation as a consequence of such turnover. These models are of three general kinds: those attributing hybrid infertility to the process of transposition, those attributing hybrid infertility to mispairing between chromosomes of divergent repetitive DNA composition, and those assuming that change in repetitive DNA's can reset coordinated gene regulation. These models are discussed with respect to the kinds of evidence needed for their corroboration and to their significance for questions related to macroevolutionary punctuated equilibria and genetic revolutions.

In 1966, William D. Hamilton published a landmark paper in evolutionary biology: "The Moulding of Senescence by Natural Selection." It is now apparent that this article is as important as his better-known 1964 articles on kin selection. Not only did the 1966 article explain aging, it also supplied the basic scaling forces for natural selection over the entire life history. Like the Lorentz transformations of relativistic physics, Hamilton's Forces of Natural Selection provide an overarching framework for understanding the power of natural selection at early ages, the existence of aging, the timing of aging, the cessation of aging, and the timing of the cessation of aging. His twin Forces show that natural selection shapes survival and fecundity in different ways, so their evolution can be somewhat distinct. Hamilton's Forces also define the context in which genetic variation is shaped. The Forces of Natural Selection are readily manipulable using experimental evolution, allowing the deceleration or acceleration of aging, and the shifting of the transition ages between development, aging, and late life. For these reasons, evolutionary research on the demographic features of life history should be referred to as "Hamiltonian."