Theoretical Biology Forum最新文献

Although most discussions on the origin and evolution of insect wings and metamorphosis have assumed that the ancestors of winged insects were terrestrial, it now seems possible that they were actually aquatic. Changing the basic assumptions affects our interpretations of the origin of metamorphosis and our understanding of insect diversity. It is argued that the ancestors of winged insects were similar to primitive mayflies, developing from aquatic larvae into terrestrial adults, and that metamorphosis originated as an inevitable consequence of an amphibiotic life cycle. It is suggested that the first pupae resembled those of Megaloptera.

Based on the Recognition Concept of species, the specific-mate contact model posits that mating systems develop as combinations of two fundamental courtship strategies that we interpret here in terms of behavioural heterochrony: territorial mate-attraction evolved as an effect of peramorphosis whereas group-living mate-seeking evolved as an effect of paedomorphosis. We tested this hypothesis on primates in a phylogenetic and paleo-climatic context. Our results suggest that primate promiscuity (both males and females are mate-seekers) evolved with group-living from ancestral pair-living monogamy (both males and females are mate-attractors) in the Palaeogene, as the result of a slowdown in growth (neoteny) caused by increased environmental predictability. A secondary return to territorial monogamy probably evolved as the result of accelerated growth driven by seasonality (acceleration). Polygamy evolved in the Neogene during periods of forest fragmentation and environmental unpredictability. Small monogamous ancestors evolved seasonal polyandry (female attraction) as an effect of truncated development (progenesis). Large promiscuous, neotenic ancestors evolved non-seasonal polygyny (male attraction) as an effect of prolonged development (hypermorphosis) in males. We conclude that social heterochrony offers alternative explanations for the coevolution of life history and mating be-haviour; and we discuss the implications of our model for human social evolution.

Since the ENCODE project published its final results in a series of articles in 2012, there is no consensus on what its implications are. ENCODE's central and most controversial claim was that there is essentially no junk DNA: most sections of the human genome believed to be «junk» are functional. This claim was met with many reservations. If researchers disagree about whether there is junk DNA, they have first to agree on a concept of function and how function, given a particular definition, can be discovered. The ENCODE debate centered on a notion of function that assumes a strong dichotomy between evolutionary and non-evolutionary function and causes, prevalent in the Modern Evolutionary Synthesis. In contrast to how the debate is typically portrayed, both sides share a commitment to this distinction. This distinction is, however, much debated in alternative approaches to evolutionary theory, such as the EES. We show that because the ENCODE debate is grounded in a particular notion of function, it is unclear how it connects to broader debates about what is the correct evolutionary framework. Furthermore, we show how arguments brought forward in the controversy, particularly arguments from mathematical population genetics, are deeply embedded in their particular disciplinary contexts, and reflect substantive assumptions about the evolution of genomes. With this article, we aim to provide an anatomy of the ENCODE debate that offers a new perspective on the notions of function both sides employed, as well as to situate the ENCODE debate within wider debates regarding the forces operating in evolution.