Biogeographic range expansion into South America by Coccidioides immitis mirrors New World patterns of human migration

Long-distance population dispersal leaves its characteristic signature in genomes, namely, reduced diversity and increased linkage between genetic markers. This signature enables historical patterns of range expansion to be traced. Herein, we use microsatellite loci from the human pathogen Coccidioides immitis to show that genetic diversity in this fungus is geographically partitioned throughout North America. In contrast, analyses of South American C. immitis show that this population is genetically depauperate and was founded from a single North American population centered in Texas. Variances of allele distributions show that South American C. immitis have undergone rapid population growth, consistent with an epidemic increase in postcolonization population size. Herein, we estimate the introduction into South America to have occurred within the last 9,000–140,000 years. This range increase parallels that of Homo sapiens. Because of known associations between Amerindians and this fungus, we suggest that the colonization of South America by C. immitis represents a relatively recent and rapid codispersal of a host and its pathogen.

Convex polytopes and quantization of symplectic manifolds

Quantum mechanics associate to some symplectic manifolds M a quantum model Q(M), which is a Hilbert space. The space Q(M) is the quantum mechanical analogue of the classical phase space M. We discuss here relations between the volume of M and the dimension of the vector space Q(M). Analogues for convex polyhedra are considered.

Self-recognition and abstraction abilities in the common chimpanzee studied with distorting mirrors.

The reactions of chimpanzees to regular mirrors and the results of the standard Gallup mark test have been well documented. In addition to using the mark test to demonstrate self-recognition in a regular mirror, we exposed six female chimpanzees to mirrors that produced distorted or multiplied self-images. Their reactions to their self-images, in terms of mirror-guided self-referenced behaviors, indicated that correct assessment of the source of the mirror image was made by each subject in each of the mirrors. Recognition of a distorted self-image implies an ability for abstraction in the subjects in that the distortion must be rationalized before self-recognition occurs. The implications of these results in terms of illuminating the relative importance of feature and contingency of movement cues to self-recognition are discussed.