Theoretical Biology Forum最新文献

It has long been understood that new genes evolve from duplication events and subsequent divergence. Since 2006, however, many studies have argued that entire protein-coding genes can emerge "from scratch" by recruiting "random", non-coding and functionless sequences, contrary to what was thought possible. The hypothesis of "de novo" origination is used to explain why some genes do not possess homologs and appear to be lineagespecific "orphans". Some have been implicated in important evolutionary adaptations. Unfortunately, the new field is marred by theoretical problems, false positives, misleading claims and a failure to validate. Many de novo genes are likely to be derived from diverged fragments of older genes that have since been lost in most lineages or revived in one alone. Instead of scouring genomes for evidence of de novo gene birth, improvements in detection tools and methodologies are now urgently required.

This review explores the critical role of information in biological regulation, extending beyond traditional concepts of homeostasis and homeorhesis. Information, recognized as a fundamental entity alongside matter and energy, governs the dynamic and adaptive processes of living systems. By proposing the concept of «homeoinformation », this paper highlights the continuous processing and integration of information as the foundation for stability and adaptation in life. This perspective offers a more comprehensive framework for understanding the complexity of biological systems and opens new avenues for research into the intricate dynamics of life.

Using as a narrative theme the example of Darwin's finches, a microscopic agent-based model is introduces to study sympatric speciation as a result of competition for resources in the same ecological niche. Varying competition among individuals and resources distribution, the model exhibits some of the main features of evolutionary branching processes. The model can be extended to include spatial effects, different genetic loci, sexual mating and recombination, etc. and is well-suited for teaching the theory of evolution.

In 2007, David S. Wilson and Edward O. Wilson (27) pointed out that, Richard Dawkins had admitted that, contrary to what he had claimed in his book The Selfish Gene (1976) (7), the idea that only the gene is a fundamental unit of selection cannot be used as an argument against the notion of group selection. This elicited a sharp denial from Dawkins (30), which was followed by an explanatory reply by Wilson and Wilson (33) and another vehement denial by Dawkins (34). I analyse the prehistory of this surprisingly complex and convoluted dispute and subsequently disentangle it. My conclusion is that much of it is based on a series of misunderstandings. First, Wilson's and Wilson's (27) original interpretation of Dawkins' selfish gene argument was incorrect. Second, in their explanatory reply (33), they distinguished between two kinds of group selection: the idea that groups can be units of selection (theoretical group selection) and the idea that group selection plays a functional role in evolution (functional group selection). They clarified that their claim concerned theoretical group selection, not functional group selection. Third, that clarified claim was correct and not correct. It was incorrect because Dawkins has never explicitly acknowledged that he had erred by developing his selfish gene theory as an implicit argument against this kind of group selection. However, the distinction that he made, by 1978, between two kinds of unit of selection, replicators (genes) and vehicles (somas), does imply such an acknowledgment since it holds that groups can be units of selection (vehicles). In this important sense, Wilson's and Wilson's clarified claim (33) was correct. Fourth, Dawkins' second denial (34) concerned functional group selection, not theoretical group selection.

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.