During my residence in the Amazon district I took every opportunity of determining the limits of species, and I soon found that the Amazon, the Rio Negro and the Madeira formed the limits beyond which certain species never passed. The native hunters are perfectly acquainted with this fact, and always cross over the river when they want to procure particular animals, which are found even on the ...

The problem of genetic hitch-hiking in a geographically subdivided population is analysed under the assumption that migration rates among populations are relatively small compared with the selection coefficient for a newly arising advantageous allele. The approximate method used in the paper is valid when the number of emigrants per generation (Nm) is less than one. The approximate analysis sho...

THE ACTION OF hfINUTE FACTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 629 Blond-Minute . . . . . . . . , . . . , . . . . . . . . . . , . . . . . . . . . , , , . . , . , . . . . Autosomal Minutes and sex-linked spots. . . . . . . . . . . . . . . . . . . . . . The specificity of the effects of sex-linked and autosomal Minutes. . . . . . . ...

PAGE INTRODUCTION .................................................................. I35 Coincidence of widely separated regions. , 138 Coincidence in the second chromosome. 146 Coincidence in the third chromosome. 148 Coincidence in other forms 148 The mechanism of crossing over 148 Triple crossing over .: .. I49 Maximum and minimum coincidence. I53 The distance between the breaking points in ...

The achievements of a group frequently depend on the efforts of just a few members but represent a public good benefit to all members. This paper investigates such a situation: the private provision of a public good whose level is determined as the maximum effort made by a group member. Members’ costs of effort are envisioned as either commonly known or privately known. With perfect information...

The analysis of crossover interference in many creatures is complicated by the presence of two kinds of crossovers, interfering and noninterfering. In such creatures, the values of the traditional indicators of interference are subject not only to the strength of interference but also to the relative frequencies of crossing over contributed by the two kinds. We formalize the relationship among ...