抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

Genetics and analysis of quantitative traits

Much research in the last two decades has demon- strated that human responses deviate from the performance deemed normative according to various models of decision mak- ing and rational judgment (e.g., the basic axioms of utility theory). This gap between the normative and the descriptive can be inter- preted as indicating systematic irrationalities in human cognition. However, four alternative interpretations preserve the assumption that human behavior and cognition is largely rational. These posit that the gap is due to (1) performance errors, (2) computational limitations, (3) the wrong norm being applied by the experi- menter, and (4) a different construal of the task by the subject. In the debates about the viability of these alternative explanations, attention has been focused too narrowly on the modal response. In a series of experiments involving most of the classic tasks in the heuristics and biases literature, we have examined the implica- tions of individual differences in performance for each of the four explanations of the normative/descriptive gap. Performance er- rors are a minor factor in the gap; computational limitations un- derlie non-normative responding on several tasks, particularly those that involve some type of cognitive decontextualization. Un- expected patterns of covariance can suggest when the wrong norm is being applied to a task or when an alternative construal of the task should be considered appropriate.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0140525X00003435

Individual differences in reasoning: Implications for the rationality debate?

Species are often faced with an evolutionary trade-off between performing a few activities well (specialists) and many activities poorly (generalists). This trade-off is a central concern for evolutionary ecologists interested in the coexistence of species and the coexistence of genotypes within species. At least four factors that influence the relative fitness of generalists and specialists have been identified (table 1). The first factor is the shape of the fitness et. Following Levins (1962, 1968), figure 1 shows fitness associated with two activities, such as resources that require different techniques to capture or habitats that require different behaviors to exploit successfully. Each genotype is represented by a point, and the set of genotypes that exist in the population is represented by a line. Both fitness ets in figure 1have a negative slope, which indicates that fitness associated with one activity can be increased only at the expense of fitness associated with the other activity. Generalists are only slightly inferior to the specialists in the convex fitness et (A) and are greatly inferior to the specialists in the concave fitness et (B). A variety of models conclude that the fitness et must be concave for the advantages of specialization to outweigh the costs (see, e.g., Levins 1962, 1968; MacArthur and Levins 1964, 1967; MacArthur and Pianka 1966; Pulliam 1974; Rosenzweig 1974; Lawlor and Maynard Smith 1976; Wilson and Turelli 1986). It is important to emphasize that fitness ets do not always have a negative slope. Some activities can be performed well without compromising other activities, which leads to a jack of all trades that is also a master of all. Several authors have properly cautioned that trade-offs between activities must be demonstrated and not assumed (e.g., Bernays and Graham 1988; Futuyma nd Moreno 1988). Nevertheless, few would doubt the basic existence of trade-offs or their importance in the evolution of specialization. The second factor affecting fitness is activity selection. The foregoing models assume that each genotype performs both activities so that fitness is a weighted average of the xand y-coordinate values. If animals can choose to perform one activity and avoid the other, however, specialists can be favored even when the fitness et is convex because the cost of specializing-inferior performance at the other activity-is seldom experienced (see, e.g., Imanishi 1938, 1941, 1949; Kani 1944; Svardson 1949; MacArthur and Pianka 1966; Charnov 1976). Activity selection has been modeled in two ways. First, we can assume that a

On the Coexistence of Specialists and Generalists

Many natural populations undergo radical and unpredictable fluctuations, associated with stochastic environmental conditions Under such circumstances, fitness of a genotype (or ‘strategy’) is defined as the geometric mean of the intergenerational genotypic population growth ratel(t) Unfortunately, this population-level criterion has proved difficult to apply at the level of individual organisms

/pdf/individual-adaptations-in-stochastic-environments-cnwuw3i2kr.pdf

Individual adaptations in stochastic environments.

Populations that live in environments with different habitats have to distribute their offspring over these habitats. When population densities go to equilibrium, the evolutionary optimum is an ideal free distribution. Under an ideal free distribution, no offspring should be put into sink habitats. However, when the environmental conditions in a habitat are not constant but fluctuate, allocating offspring to sink habitats can increase the long term growth rate of a population. We demonstrate this principle in a simple model for offspring allocation. As a consequence, it is possible that populations persist in environments that only consist of sink habitats.

/pdf/populations-can-persist-in-an-environment-consisting-of-sink-5eut1gq1sz.pdf

Populations can persist in an environment consisting of sink habitats only

Periodical cicadas (Magicicada spp.) are known for their strikingly synchronized emergence, strong site tenacity, and unusually long (17- and 13-yr) life cycles for insects. Several explanations have been proposed for the origin and maintenance of synchronization. However, no satisfactory explanations have been made for the origins of the prime-numbered life cycles. I present an evolutionary hypothesis of a forced developmental delay due to climate cooling during ice ages. Under this scenario, extremely low adult densities, caused by their extremely long juvenile stages, selected for synchronized emergence and site tenacity because of limited mating opportunities. The prime numbers (13 and 17) were selected for as life cycles because these cycles were least likely to coemerge, hybridize, and break down with other synchronized cycles.

The evolutionary origins of periodical cicadas during ice ages

In this paper we investigate the evolutionary changes of chess variants. For this purpose we propose a measure of the game’s entertaining impact. The measure is derived from grandmaster games and is applicable to chess variants independent of the game under consideration. For the case where no grandmaster games are available we perform computer self-play experiments to estimate the measure. For several old chess variants the measure as well as other measures, such as the search-space complexity and draw rate, are calculated. Some relationships between the measures investigated are found. Based on these relationships the evolutionary changes of chess variants are discussed.

/pdf/a-metric-for-entertainment-of-boardgames-its-implication-for-18rzj9jnn2.pdf

Jin Yoshimura

Papers

On the Coexistence of Specialists and Generalists

Individual adaptations in stochastic environments.

Populations can persist in an environment consisting of sink habitats only

The evolutionary origins of periodical cicadas during ice ages

A Metric for Entertainment of Boardgames : its implication for evolution of chess variants