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Research reveals that fast-running lacertid lizards exhibit longer hindlimbs than their forelimbs with no other variables influencing the speed or endurance of animal's locomotor apparatus. Data indicate that the evolution of sprint ability and endurance seem to be interdependent.

Data from highly variable loci such as microsatellites should be analyzed because of their ability to resolve many issues pervading conservation and evolutionary biology. A careful evaluation is required to differentiate the new information from less variable markers and traditionally derived ones. An example is provided to demonstrate that the level of differentiation and genetic distance between groups is largely influenced by the heterozygosity level for the highly variable loci.

The assumption that genetic variances and covariances remain constant in applications of quantitative methods to study macroevolutionary patterns is tested among 28 populations of the Phyllotis darwini species group of leaf-eared mice. Pairwise matrix correlations of correlation matrices are consistently very high and show no significant association between matrix similarity and phylogenetic relatedness.

Evolutionary constraints, whether due to developmental programs or genetic covariance structure, make the evolution of certain phenotypes more likely than others. Biases toward certain morphologies can control rates of evolution, [...]

The evolution of body size among chuckwallas, genus Sauromalus, was investigated through the analysis of phylogeny which was constructed based on sequence variation in the mitochodrial cytochrome b gene. The results showed that the body mass of the iguanines depends on a number of factors including sexual selection, competition, resource availability and predation. It was also found that cytochrome b haplotype divergence is high between geographically proximate populations of the lizards, indicating that female dispersal and gene flow is limited.

The genetic obstacles to sympatric modes of speciation have been forcefully argued by a number of authors, most of whom maintain that geographical isolation during allopatry must predate the evolution [...]

One of the keys to comparative analyses in evolutionary biology is the ability to control for the phylogenetic influence on trait variation among related taxa. We show that two of [...]

Key words.--Adaptive radiation, competition, Darwin, division of labor, economics, Malthus, natural selection, progress. Recieved February 21, 1995. Accepted may 1, 1995 The concept of progress has lately attracted considerable attention, [...]

Molecular techniques allow us to estimate the ancestral phylogeny of extant taxa, together with the time of each branching point. The pattern of phylogeny becomes more accurate as more data [...]

Ernst Mayr's contributions to the growth of evolutionary biology have been more multifaceted than his scientific work alone, impressive as that is. In addition to the publication of his Systematics [...]

A study was conducted to analyze the geographic variation in oviporous preference of the western anise swallowtail butterfly, Papilio zelicaon, using different plants as hosts. Results revealed a variation in the degree of plant preference, wherein high-ranking hosts had the highest preference. There was no positive correlation between different geographic populations and the hosts. Results reflected that any increase in host preference was part of the evolutionary preference hierarchy.

Recently, Guilford and Cuthill (1991) and Rosenberg (1991) discussed the relative role of individual benefits (experienced by an individual prey itself), kin benefits (experienced by the relatives of the individual) [...]

We describe a multilocus model that incorporates pleiotropic stabilizing selection on a large number of characters. We find many different stable equilibria with different levels of polymorphism and additive genetic variability. The results lends support to Wright's concept of a complex adaptive surface with many peaks of different heights. The model assumes that alleles contribute additively to the characters. We analyze the multilocus model by first considering a two-locus model. The two-locus model depends critically on having loci of different effect and on having the optimum phenotype not be that of a completely heterozygous individual. The effects of different loci need to differ only by less than a factor of two. For the multilocus, multicharacter model, we assume that completely heterozygous individuals do not have optimum phenotype. By restricting attention to a two-allele model, we also assume that there are no alleles that can affect all characters in all possible combinations of directions.

The timing and mode of lineage diversification in Senna (Leguminosae) was explored to gain insights into the evolutionary role of extrafloral nectaries (EFNs) which attract ants and contribute to formation of ecologically important ant-plant mutualisms. The colonization of new habitats appearing with the early uplift of the Andes promoted by EFNs might explain the distinctive geographic concentration of the EFN clade in South America.

A quantitative-genetic experimental study was carried out to understand the role of predation risk in the expression and evolution of life-history and mating-system traits in a hermaphroditic freshwater snail (Physa acuta). The results provide insight into numerous potential roles of enemies in mating-system expression and evolution.

The different symmetrical 2*2 games as basis for repeated and evolutionary games are used to demonstrate the existence of a co-operation dilemma both in 'classical' game theory (with a fixed set of players) as well as in evolutionary game theory (population dynamics). The relevance of such models for research on the large biodiversity and variation in cooperative efforts both in biological and social systems are also discussed.

The research data on the size-dependent survival in the early life history of fish was utilized to obtain estimates of standardized selection differentials from 40 studies. The results revealed that 77% of estimated selection differentials favored larger size and that the strength of selection was more than five times compared to those observed in terrestrial taxa.

The article explains a recently developed phylogenetic approach, which is employed to study the evolution of color polymorphism in Dendrobates pumilio, a well-known poison-dart frog. The shifts in coloration in aposematic species are shown to be extremely frequent and regular.

The genetic architecture of a suite of floral traits of the annual plant, Ipomoea hederacea, is examined to demonstrate the significance of the genetic constraints for the evolution of character displacement. The rate of evolution of reproductive character displacement is shown to be highly limited by the genetic architecture of the floral traits.

Numerous studies are conducted to explain the various latitudinal variations taking place in the subspecific diversification of different species of birds. The analysis proves that the phenotypic differentiation of populations is greater at lower latitudes within the species.

Several simulation studies are employed to explain the flaws of the phylogenetic tests of irreversible evolution, including the Dollow's law that states that a complex trait cannot revolve in an identical manner. Incorrect assignment of the root state frequencies and neglect of the character state are shown to be the two major causes of errors occurring in these methods.

The study is done to investigate the relationship between ease of fertilization and susceptibility to polyspermy within and among three congeneric sea urchins. The result indicates within and among species, individuals and species, which produce eggs capable of fertilization at relatively low sperm, concentrations are more susceptible to polyspermy.

Efforts to conserve populations may be aided by accurate estimation of effective population size ([N.sub.e]), an indicator of the expected rate of loss of genetic variation. A parameter of central [...]