Complexity and Verisimilitude: Realism for Ecology

When data are limited, simple models of complex ecological systems tend to wind up closer to the truth than more complex models of the same systems. This greater proximity to the truth, or verisimilitude, leads to greater predictive success. When more data are available, the advantage of simplicity decreases, and more complex models may gain the upper hand. In ecology, holistic models are usually simpler than reductionistic models. Thus, when data are limited, holistic models have an advantage over reductionistic models, with respect to verisimilitude and predictive success. I illustrate these points with models designed to explain and predict the numbers of species on islands.     

Between beanbag genetics and natural selection

The encounter between the Darwinian theory of evolution and Mendelism could be resolved only when reductionist tools could be applied to the analysis of complex systems. The instrumental reductionist interpretation of the hereditary basis of continuously varying traits provided mathematical tools which eventually allowed the construction of the Modern Synthesis of the theory of evolution.When genotypic as well as environmental variance allow the isolation of parts of the system, it is possible to apply Mendelian reductionism, that is , to treat the phenotypic trait as if ti causally determined by discrete genes for the trait. howeverm such a beanbag genetics approach obscures the system's eye-view. The concept of heritability, defined as the proportion of the total phenotypic variance due to (additive) hereditary variation, asserts that genetic elements have discrete effects; but by relating to the genotypic variance, it avoids the trap of reffering to genes for characters.     

奥德姆的生态思想是整体论吗?

奥德姆的生态思想是妥协的整体论,有还原论的一面。把生态系统看作是功能性整体、承认生态系统各层次的涌现属性属于整体论,把生态关系简化为能量关系、把生态系统看作是物理系统的分析方法则是还原论的。这种矛盾的生态思想决定了其方法论的先天不足:生态模型的内在逻辑关系没有理顺;较少考虑生态系统的进化;生态研究方法的排它性等。但是,它并不妨碍奥德姆的生态思想在夯实生态学的本体论基础、促进理论生态学和生态工程学的形成、协调生态整体论与还原论分歧、奠定生态系统服务功能研究基础等方面发挥重要作用。要超越生态整体论与还原论,繁荣发展生态复杂性理论也许是最好的选择。     

Economics, Biology, and Naturalism: Three Problems Concerning the Question of Individuality

The paper examines the ramifications of naturalism with regard to the question of individuality in economics and biology. Economic theory has to deal with whether households, firms, and states are individuals or are mere entities such as clubs, networks, and coalitions. Biological theory has to deal with the same question with regard to cells, organisms, family packs, and colonies. To wit, the question of individuality in both disciplines involves three separate problems: the metaphysical, phenomenist, and ontological. The metaphysical problem is concerned with purposeful action: Is the firm or organism exclusively the product of efficient causality (optimization) or is it motivated by final causality (purposefulness)? The phenomenist problem is interested in the substantiality of essences: Is the firm's or organism's scheme of institutions/traits deep or is it extraneous to identity? The ontological problem is related to the issue of reductionism: Is the behavior of lower-level organization governed by a pre-constituted entities or is it context-sensitive? The paper finds that theoretical differences run along the naturalist/anti-naturalist divide rather than along disciplinary specialization. Also, the paper finds that it is not inconsistent for the same theorist to be naturalist with regard to one problem and anti-naturalist with respect to the other two problems.     

Genetic Causation in Complex Regulatory Systems: An Integrative Dynamic Perspective

The logic of genetic discovery has changed little over time, but the focus of biology is shifting from simple genotype–phenotype relationships to complex metabolic, physiological, developmental, and behavioral traits. In light of this, the traditional reductionist view of individual genes as privileged difference-making causes of phenotypes is re-examined. The scope and nature of genetic effects in complex regulatory systems, in which dynamics are driven by regulatory feedback and hierarchical interactions across levels of organization are considered. This review argues that it is appropriate to treat genes as specific actual difference-makers for the molecular regulation of gene expression. However, they are often neither stable, proportional, nor specific as causes of the overall dynamic behavior of regulatory networks. Dynamical models, properly formulated and validated, provide the tools to probe cause-and-effect relationships in complex biological systems, allowing to go beyond the limitations of genetic reductionism to gain an integrative understanding of the causal processes underlying complex phenotypes.     

Opinion: the species problem, can we achieve a universal concept?

One of the so called 'species problems' is that no universal concept exists. There is a tendency among microbiologists to criticize the hitherto devised concept. It is considered by some researchers as being too conservative and not suitable to be compared with those for eukaryotes. However, such problem is not only restricted to prokaryotes, but among other taxonomies comparisons seem to be impossible. As it is argued, the underlying cause to this problem is the reductionistic and monistic use of taxonomy. Analyzing the more than 22 devised concepts it seems possible to achieve a universal species concept. However, this might not be pragmatic. For the time being, a pluralistic sense of the species concept might be accepted, and one will have to recognize that any comparison among different taxonomies will be difficult.     

The century beyond the gene

In an increasing number of biological laboratories, the focus of research is shifting from sequence data to the functional meaning of that data. No longer content with structural mappings, there is a renewed interest abroad in what the United States Department of Energy calls, ’Bringing Genomes to Life’. For many, this means a movement beyond ’reductionism’ to a ’systems biology’. The question is, what does this mean?     

How evolutionary biology challenges the classical theory of rational choice

A fundamental philosophical question that arises in connection with evolutionary theory is whether the fittest patterns of behavior are always the most rational. Are fitness and rationality fully compatible? When behavioral rationality is characterized formally as in classical decision theory, the question becomes mathematically meaningful and can be explored systematically by investigating whether the optimally fit behavior predicted by evolutionary process models is decision-theoretically coherent. Upon investigation, it appears that in nontrivial evolutionary models the expected behavior is not always in accord with the norms of the standard theory of decision as ordinarily applied. Many classically irrational acts, e.g. betting on the occurrence of one event in the knowledge that the probabilities favor another, can under certain circumstances constitute adaptive behavior. One interesting interpretation of this clash is that the criterion of rationality offered by classical decision theory is simply incorrect (or at least incomplete) as it stands, and that evolutionary theory should be called upon to provide a more generally applicable theory of rationality. Such a program, should it prove feasible, would amount to the logical reduction of the theory of rational choice to evolutionary theory.