A new statistical method for estimating divergence dates of species from DNA sequence data by a molecular clock approach is developed. This method takes into account effectively the information contained in a set of DNA sequence data. The molecular clock of mitochondrial DNA (mtDNA) was calibrated by setting the date of divergence between primates and ungulates at the Cretaceous-Tertiary boundary (65 million years ago), when the extinction of dinosaurs occurred. A generalized least-squares method was applied in fitting a model to mtDNA sequence data, and the clock gave dates of 92.3 +/- 11.7, 13.3 +/- 1.5, 10.9 +/- 1.2, 3.7 +/- 0.6, and 2.7 +/- 0.6 million years ago (where the second of each pair of numbers is the standard deviation) for the separation of mouse, gibbon, orangutan, gorilla, and chimpanzee, respectively, from the line leading to humans. Although there is some uncertainty in the clock, this dating may pose a problem for the widely believed hypothesis that the pipedal creature Australopithecus afarensis, which lived some 3.7 million years ago at Laetoli in Tanzania and at Hadar in Ethiopia, was ancestral to man and evolved after the human-ape splitting. Another likelier possibility is that mtDNA was transferred through hybridization between a proto-human and a proto-chimpanzee after the former had developed bipedalism.

Dating of the human-ape splitting by a molecular clock of mitochondrial DNA.

ilbstract. Autocorrelation is a very general statistical property of ecological variables observed across geographic space; its most common forms are patches and gradients. Spatial autocorrelation. which comes either from the physical forcing of environmental variables or from community processes, presents a problem for statistical testing because autocorrelated data violate the assumption of independence of most standard statistical procedures. The paper discusses first how autocorrelation in ecological variables can be described and measured. with emphasis on mapping techniques. Then. proper statistical testing in the presence of autocorrelation is briefly discussed. Finally. ways are presented of explicitly introducing spatial structures into ecological models. Two approaches are proposed: in the raw-data approach, the spatial structure takes the form of a polynomial of the x and .v geographic coordinates of the sampling stations; in the matrix approach. the spatial structure is introduced in the form of a geographic distance matrix among locations. These two approaches are compared in the concluding section. A table provides a list of computer programs available for spatial analysis.

https://www.jstor.org/stable/pdfplus/1939924.pdf

Spatial Autocorrelation: Trouble or New Paradigm?

Border Gateway Protocol (BGP) is the protocol backing the core routing decisions on the Internet. It maintains a table of IP networks or 'prefixes' which designate network reachability among autonomous systems (AS). Point of concern in BGP is its lack of effective security measures which makes Internet vulnerable to different forms of attacks. Many solutions have been proposed till date to combat BGP security issues but not a single one is deployable in practical scenario. Any security proposal with optimal solution should offer adequate security functions, performance overhead and deployment cost. This paper critically analyzes the deployment issues of best three proposals considering trade-off between security functions and performance overhead.

Comparative analysis of

Darwin (1859, pp. 11-14, 143-150) stressed the evolutionary importance of covariation between characters in populations and its "most imperfectly understood" connection with correlated responses to artificial and natural selection. After the turn of the century the discoveries of pervasive pleiotropy and linkage of Mendelian factors revealed the underlying genetic mechanisms. Existing theory on the dynamics of correlated characters has been developed in the limited framework of practical plant and animal breeding. Methods of multivariate analysis, functional analysis and optimality criteria popular among evolutionists, do not account for dynamical constraints imposed by the pattern of genetic variation within populations. Consideration of phenotypic variation often does not suggest any clear mechanism connecting growth patterns or adult variation to interspecific evolution. When there is individual variation in development, no necessary correspondence exists between ontogenetic and adult variation in a population (Cock, 1966, pp. 148-15 1). It is also common for the pattern of adult variation within a species to differ from that at higher taxonomic levels (Simpson, 1953, pp. 25-29). An example which will be investigated here is the brain weight:body weight relationship. At various taxonomic levels, brain and body weights tend to follow the allometric equation

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1558-5646.1979.tb04694.x

Quantitative genetic analysis of multivariate evolution, applied to brain:body size allometry.

The principles of classification and a classification of mammals. Bulletin of the AMNH ; v. 85

Occlusal variation in chinese immigrants to the United Kingdom and their off-spring

Skeletal lead levels are unexpectedly high (averaging 118 ppm and reaching 424 ppm maximum) in seventeenth to nineteenth century Caribbean slave skull remains. Younger specimens show significantly lower lead concentrations. Historical data confirm the supposition from skeletal lead measurements that blood lead levels probably resulted in lead intoxication symptoms in a significant fraction of this population.

Patterning of skeletal lead content in barbados slaves

Multivariate morphometric analyses of the wrist morphology of monkeys, apes and humans indicate that there is a fundamental difference between cercopithecoids and hominoids which can be related to functional and behavioral differences. The wrists of the Miocene fossil hominoids (Dryopithecus africanus and Pliopithecus vindobonensis) are almost completely monkey-like in their structure.

Osteometric Shape Relationships in the Wrist Joint of Some Anthropoids

The "out-of-Africa" models for origins of modern Homo sapiens incorporate Skhul as one site documenting that early origination. However, only Skhul V is usually considered in the comparative craniology of the question, neglecting the other substantial crania, Skhul IV and IX. Craniometric comparison demonstrates that IV and IX amplify the picture of continuous gradations of Neandertal-to-modern variations throughout the Levant; much variation is thus represented within this one site, raising serious questions about Neandertals and moderns being discrete and long-separated species. Qafzeh 6 too is craniophenetically closer to Neandertals than to the true anatomically modern people of the European Upper Paleolithic. Proper distance analysis of Border Cave 1 cranium shows it is actually far removed from modern African populations. References to Qafzeh, Skhul, and Border Cave as "fully anatomically modern" require reconsideration.

Metrical reconsideration of the Skhul IV and IX and Border Cave 1 crania in the context of modern human origins.

Disagreement is current over the question of whether relatively large teeth in some large primates are a natural outcome of growth trends instead of an indication of intrinsic differences. A cross-primate survey of dental scaling relative to skull (and inferred body) size is given in this study, using a principal component technique to measure the multivariate growth relation between two sets of data: dental size and cranial size. Cheek teeth are strongly positively allometric in restriced taxonomic groups, especially in cercopithecoids. Conversely, the allometry drops to an almost linear proportional growth relation when variation in diet is controlled.

Robert S. Corruccini

Papers

Occlusal variation in chinese immigrants to the United Kingdom and their off-spring

Patterning of skeletal lead content in barbados slaves

Osteometric Shape Relationships in the Wrist Joint of Some Anthropoids

Metrical reconsideration of the Skhul IV and IX and Border Cave 1 crania in the context of modern human origins.

Multivariate dental allometry in primates.