Niche inheritance: a cooperative pathway to enhance cancer cell fitness though ecosystem engineering

Cancer cells can be described as an invasive species that is able to establish itself in a new environment. The concept of niche construction can be utilized to describe the process by which cancer cells terraform their environment, thereby engineering an ecosystem that promotes the genetic fitness of the species. Ecological dispersion theory can then be utilized to describe and model the steps and barriers involved in a successful diaspora as the cancer cells leave the original host organ and migrate to new host organs to successfully establish a new metastatic community. These ecological concepts can be further utilized to define new diagnostic and therapeutic areas for lethal cancers.Comment: 8 pages, 1 Table, 4 Figure

Baldwinian accounts of language evolution

Since Hinton & Nowlan published their seminal paper (Hinton & Nowlan 1987), the neglected evolutionary process of the Baldwin effect has been widely acknowledged. Especially in the field of language evolution, the Baldwin effect (Baldwin 1896d, Simpson 1953) has been expected to salvage the long-lasting deadlocked situation of modern linguistics: i.e., it may shed light on the relationship between environment and innateness in the formation of language.However, as intense research of this evolutionary theory goes on, certain robust difficulties have become apparent. One example is genotype-phenotype correlation. By computer simulations, both Yamauchi (1999, 2001) and Mayley (19966) show that for the Baldwin effect to work legitimately, correlation between genotypes and phenotypes is the most essential underpinning. This is due to the fact that this type of the Baldwin effect adopts as its core mechanism Waddington's (1975) "genetic assimilation". In this mechanism, phenocopies have to be genetically closer to the innately predisposed genotype. Unfortunately this is an overly naiive assumption for the theory of language evolution. As a highly complex cognitive ability, the possibility that this type of genotype-phenotype correlation exists in the domain of linguistic ability is vanishingly small.In this thesis, we develop a new type of mechanism, called "Baldwinian Niche Construction (BNC), that has a rich explanatory power and can potentially over¬ come this bewildering problem of the Baldwin effect. BNC is based on the theory of niche construction that has been developed by Odling-Smee et al. (2003). The incorporation of the theory into the Baldwin effect was first suggested by Deacon (1997) and briefly introduced by Godfrey-Smith (2003). However, its formulation is yet incomplete.In the thesis, first, we review the studies of the Baldwin effect in both biology and the study of language evolution. Then the theory of BNC is more rigorously developed. Linguistic communication has an intrinsic property that is fundamentally described in the theory of niche construction. This naturally leads us to the theoretical necessity of BNC in language evolution. By creating a new linguistic niche, learning discloses a previously hidden genetic variance on which the Baldwin 'canalizing' effect can take place. It requires no genetic modification in a given genepool. There is even no need that genes responsible for learning occupy the same loci as genes for the innate linguistic knowledge. These and other aspects of BNC are presented with some results from computer simulations

The role of visual adaptation in cichlid fish speciation

D. Shane Wright (1) , Ole Seehausen (2), Ton G.G. Groothuis (1), Martine E. Maan (1) (1) University of Groningen; GELIFES; EGDB(2) Department of Fish Ecology & Evolution, EAWAG Centre for Ecology, Evolution and Biogeochemistry, Kastanienbaum AND Institute of Ecology and Evolution, Aquatic Ecology, University of Bern.In less than 15,000 years, Lake Victoria cichlid fishes have radiated into as many as 500 different species. Ecological and sexual sel ection are thought to contribute to this ongoing speciation process, but genetic differentiation remains low. However, recent work in visual pigment genes, opsins, has shown more diversity. Unlike neighboring Lakes Malawi and Tanganyika, Lake Victoria is highly turbid, resulting in a long wavelength shift in the light spectrum with increasing depth, providing an environmental gradient for exploring divergent coevolution in sensory systems and colour signals via sensory drive. Pundamilia pundamila and Pundamilia nyererei are two sympatric species found at rocky islands across southern portions of Lake Victoria, differing in male colouration and the depth they reside. Previous work has shown species differentiation in colour discrimination, corresponding to divergent female preferences for conspecific male colouration. A mechanistic link between colour vision and preference would provide a rapid route to reproductive isolation between divergently adapting populations. This link is tested by experimental manip ulation of colour vision - raising both species and their hybrids under light conditions mimicking shallow and deep habitats. We quantify the expression of retinal opsins and test behaviours important for speciation: mate choice, habitat preference, and fo raging performance

“Economic man” in cross-cultural perspective: Behavioral experiments in 15 small-scale societies

Researchers from across the social sciences have found consistent deviations from the predictions of the canonical model of self-interest in hundreds of experiments from around the world. This research, however, cannot determine whether the uniformity results from universal patterns of human behavior or from the limited cultural variation available among the university students used in virtually all prior experimental work. To address this, we undertook a cross-cultural study of behavior in ultimatum, public goods, and dictator games in a range of small-scale societies exhibiting a wide variety of economic and cultural conditions. We found, first, that the canonical model – based on self-interest – fails in all of the societies studied. Second, our data reveal substantially more behavioral variability across social groups than has been found in previous research. Third, group-level differences in economic organization and the structure of social interactions explain a substantial portion of the behavioral variation across societies: the higher the degree of market integration and the higher the payoffs to cooperation in everyday life, the greater the level of prosociality expressed in experimental games. Fourth, the available individual-level economic and demographic variables do not consistently explain game behavior, either within or across groups. Fifth, in many cases experimental play appears to reflect the common interactional patterns of everyday life