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The article focuses on a study related to structure-function covariation with nonfeeding ecological variables influences evolution of feeding specialization in Carnivora. It concludes that mechanisms of obligate shape covariation with nonfeeding variables can produce performance changes resembling those arising from feeding adaptations in Carnivora.

The composition of the ancient martian crust is a key ingredient in deciphering the environment and evolution of early Mars. We present an analysis of the composition of large craters in the martian northern plains based on data from spaceborne imaging spectrometers. Nine of the craters have excavated assemblages of phyllosilicates from ancient, Noachian crust buried beneath the plains' cover. The phyllosilicates are indistinguishable from those exposed in widespread locations in the southern highlands, demonstrating that liquid water once altered both hemispheres of Mars. [ABSTRACT FROM AUTHOR]

Several models exist to describe the growth and evolution of Earth; however, variables such as the type of precursor materials, extent of mixing, and material loss during accretion are poorly constrained. High-precision palladium-silver isotope data show that Earth's mantle is similar in 109Ag/109Ag to primitive, volatile-rich chondrites, suggesting that Earth accreted a considerable amount of material with high contents of moderately volatile elements. Contradictory evidence from terrestrial chromium and strontium isotope data are reconcited by heterogeneous accretion, which includes a transition from dominantly volatile-depleted to volatile-rich materials with possibly high water contents. The Moon-forming giant impact probably involved the collision with a Mars-like protoplanet that had an oxidized mantle, enriched in moderately volatile elements. [ABSTRACT FROM AUTHOR]

Because mutually beneficial cooperation may unravel unless most members of a group contribute, people often gang up on free-riders, punishing them when this is cost-effective in sustaining cooperation. In contrast, current models of the evolution of cooperation assume that punishment is uncoordinated and unconditional These models have difficulty explaining the evolutionary emergence of punishment because rare unconditional punishers bear substantial costs and hence are eliminated. Moreover, in human behavioral experiments in which punishment is uncoordinated, the sum of costs to punishers and their targets often exceeds the benefits of the increased cooperation that results from the punishment of free-riders. As a result, cooperation sustained by punishment may actually reduce the average payoffs of group members in comparison with groups in which punishment of free-riders is not an option. Here, we present a model of coordinated punishment that is calibrated for ancestral human conditions and captures a further aspect of reality missing from both models and experiments: The total cost of punishing a free-rider declines as the number of punishers increases. We show that punishment can proliferate when rare, and when it does, it enhances group-average payoffs. [ABSTRACT FROM AUTHOR]

Climate controls landscape evolution, but quantitative signatures of climatic drivers have yet to be found in topography on a broad scale. Here we describe how a topographic signature of typhoon rainfall is recorded in the meandering of incising mountain rivers in the western North Pacific. Spatially averaged river sinuosity generated from digital elevation data peaks in the typhoon-dominated subtropics, where extreme rainfall and flood events are common, and decreases toward the equatorial tropics and mid-latitudes, where such extremes are rare. Once climatic trends are removed, the primary control on sinuosity is rock weakness. Our results indicate that the weakness of bedrock channel walls and their weakening by heavy rainfall together modulate rates of meander propagation and sinuosity development in incising rivers. [ABSTRACT FROM AUTHOR]

Large-scale societies in which strangers regularly engage in mutually beneficial transactions are puzzling. The evolutionary mechanisms associated with kinship and reciprocity, which underpin much of primate sociality, do not readily extend to large unrelated groups. Theory suggests that the evolution of such societies may have required norms and institutions that sustain fairness in ephemeral exchanges. If that is true, then engagement in larger-scale institutions, such as markets and world religions, should be associated with greater fairness, and larger communities should punish unfairness more. Using three behavioral experiments administered across 15 diverse populations, we show that market integration (measured as the percentage of purchased calories) positively covaries with fairness while community size positively covaries with punishment. Participation in a world religion is associated with fairness, although not across all measures. These results suggest that modern prosociality is not solely the product of an innate psychology, but also reflects norms and institutions that have emerged over the course of human history. [ABSTRACT FROM AUTHOR]

During social interactions, humans often unconsciously and unintentionally imitate the behaviors of others, which increases rapport, liking, and empathy between interaction partners. This effect is thought to be an evolutionary adaptation that facilitates group living and may be shared with other primate species. Here, we show that capuchin monkeys, a highly social primate species, prefer human imitators over non-imitators in a variety of ways: The monkeys look longer at imitators, spend more time in proximity to imitators, and choose to interact more frequently with imitators in a token exchange task. These results demonstrate that imitation can promote affiliation in nonhuman primates. Behavior matching that leads to prosocial behaviors toward others may have been one of the mechanisms at the basis of altruistic behavioral tendencies in capuchins and in other primates, including humans. [ABSTRACT FROM AUTHOR]

The fossil record is the only direct source of data for studying modes (patterns) and rates of morphological change over long periods of time. Determining modes and rates is important for understanding macroevolutionary processes, but just how modes and rates vary within a taxon, and why, remain largely unaddressed. We examined patterns of morphological change in the shell of the Mesozoic marine bivalve genus Buchia over its geographic and temporal range. Most modes conformed to either random walks or stasis, and both modes and rates showed variability between locations. For example, stasis was more common in deeper marine environments, whereas random walks occurred more often at the highest paleolatitudes studied. These results indicate that the environment can play an important role in shaping patterns of evolution. [ABSTRACT FROM AUTHOR]

The article focuses on the study tracing up the genetics of evolution by various evolutionists in the U.S. It is inferred that evolutionists intends to challenge a fashionable idea examining the molecular mechanisms that underlie evolutionary change in genomes. They have projected that mutations in regulatory DNA known as cis elements form various morphological innovation allows the evolution to take place. However, it is noted that the data for finding the genetics to where evolution could be trace are inclusive, as morphological trait for the ordering of genes in each species vary considerably.

Bipedalism is a key human adaptation and a defining feature of the hominin clade. Fossil femora discovered in Kenya and attributed to Orrorin tugenensis, at 6 million years ago, purportedly provide the earliest postcranial evidence of hominin bipedalism, but their functional and phylogenetic affinities are controversial. We show that the O. tugenensis femur differs from those of apes and Homo and most strongly resembles those of Australopithecus and Paranthropus, indicating that O. tugenensis was bipedal but is not more closely related to Homo than to Australopithecus. Femoral morphology indicates that O. tugenensis shared distinctive hip biomechanics with australopiths, suggesting that this complex evolved early in human evolution and persisted for almost 4 million years until modifications of the hip appeared in the late Pliocene in early Homo. [ABSTRACT FROM AUTHOR]

There is much interest in the evolutionary forces that favored the evolution of large brains in the primate order. The social brain hypothesis posits that selection has favored larger brains and more complex cognitive capacities as a means to cope with the challenges of social life. The hypothesis is supported by evidence that shows that group size is Linked to various measures of brain size. But it has not been clear how cognitive complexity confers fitness advantages on individuals. Research in the field and laboratory shows that sophisticated social cognition underlies social behavior in primate groups. Moreover, a growing body of evidence suggests that the quality of social relationships has measurable fitness consequences for individuals. [ABSTRACT FROM AUTHOR]

The evolution of unusually large brains in some groups of animals, notably primates, has long been a puzzle. Although early explanations tended to emphasize the brain's role in sensory or technical (foraging skills, innovations, and way-finding), the balance of evidence now clearly favors the suggestion that it was the computational demands of living in large, complex societies that selected for large brains. However, recent analyses suggest that it may have been the particular demands of the more intense forms of pairbonding that was the critical factor that triggered this evolutionary development. This may explain why primate sociality seems to be so different from that found in most other birds and mammals: Primate sociality is based on bonded relationships of a kind that are found only in pairbonds in other taxa. [ABSTRACT FROM AUTHOR]

The history of Eastern African hominids has been linked to a progressive increase of open grassland during the past 8 million years. This trend was explained by global climatic processes, which do not account for the massive uplift of eastern African topography that occurred during this period. Atmosphere and biosphere simulations quantify the role played by these tectonic events. The reduced topographic barrier before 8 million years ago permitted a zonal circulation with associated moisture transport and strong precipitation. Our results suggest that the uplift itself led to a drastic reorganization of atmospheric circulation, engendering the strong aridification and paleoenvironmental changes suggested by the data. [ABSTRACT FROM AUTHOR]

Observations with the Newton X-ray Multimirror Mission satellite show a strong periodic modulation at 6.67 ± 0.03 hours of the x-ray source at the center of the 2000-year-old supernova remnant RCW 103. No fast pulsations are visible. If genetically tied to the supernova remnant, the source could either be an x-ray binary, composed of a compact object and a tow-mass star in an eccentric orbit, or an isolated neutron star. In the latter case, the combination of its age and period would indicate that it is a peculiar magnetar, dramatically slowed down, possibly by a supernova debris disc. Both scenarios require nonstandard assumptions about the formation and evolution of compact objects in supernova explosions. [ABSTRACT FROM AUTHOR]

Life-history theory attempts to provide evolutionary explanations for variations in the ways in which animal species live their lives. Recent analyses have suggested that the dimensionless ratios of several key life-history parameters are the same for different species, even across distant taxa. However, we show here that previous analyses may have given a false picture and created an illusion of invariants, which do not necessarily exist; essentially, this is because life-history variables have been regressed against themselves. The following question arises from our analysis: How do we identify an invariant? [ABSTRACT FROM AUTHOR]

Circumstellar disks play a vital evolutionary role, providing a way to move gas inward and onto a young star. The outward transfer of angular momentum allows the star to contract without breaking up, and the remnant disk of gas and particles is the reservoir for forming planets. High-resolution spectroscopy is uncovering planetary dynamics and motion within the remnant disk, and imaging at infrared to millimeter wavelengths resolves disk structure over billions of years of evolution. Most stars are born with a disk, and models of planet formation need to form such bodies from the disk material within the disk's 10-million-year life-span. [ABSTRACT FROM AUTHOR]

We characterize the evolutionary radiation of planktic foraminifera by the test size distributions of entire assemblages in more than 500 Cenozoic marine sediment samples, including more than 1 million tests. Calibration of Holocene size patterns with environmental parameters and comparisons with Cenozoic paleoproxy data show a consistently positive con-elation between test size and surface-water stratification intensity. We infer that the observed macroevolutionary increase in test size of planktic foraminifera through the Cenozoic was an adaptive response to intensifying surface-water stratification in low latitudes, which was driven by polar cooling. [ABSTRACT FROM AUTHOR]

Identification of general properties of evolutionary radiations has been hindered by the lack of a general statistical and phylogenetic approach applicable across diverse taxa. We present a comparative analytical framework for examining phylogenetic patterns of diversification and morphological disparity with data from four iguanian-lizard taxa that exhibit substantially different patterns of evolution. Taxa whose diversification occurred disproportionately early in their evolutionary history partition more of their morphological disparity among, rather than within, subclades. This inverse relationship between timing of diversification and morphological disparity within subclades may be a general feature that transcends the historically contingent properties of different evolutionary radiations. [ABSTRACT FROM AUTHOR]

The evolutionary history that led to Eocene-and-later primates of modern aspect (Euprimates) has been uncertain. We describe a skeleton of Paleocene plesiadapiform Carpolestes simpsoni that includes most of the skull and many postcranial bones. Phylogenetic analyses indicate that Carpolestidae are closely related to Euprimates. C simpsoni had long fingers and an opposable hallux with a nail. It lacked orbital convergence and an ankle specialized for leaping. We infer that the ancestor of Euprimates was primitively an arboreal grasper adapted for terminal branch feeding rather than a specialized leaper or visually directed predator. [ABSTRACT FROM AUTHOR]

Evolution can be predicted in the short term from a knowledge of selection and inheritance. However, in the long term evolution is unpredictable because environments, which determine the directions end magnitudes of selection coefficients, fluctuate unpredictably. These two features of evolution, the predictable and unpredictable, are demonstrated in a study of two populations of Darwin's finches on the Galápagos island of Daphne Major. From 1972 to 2001, Geospize fortis (medium ground finch) and Geospize scandens (cactus finch) changed several times in body size and two beak traits. Natural selection occurred frequently in both species and varied from unidirectional to oscillating, episodic to gradual. Hybridization occurred repeatedly though rerely, resulting in elevated phenotypic variances in G. scandens and a change in beak shape. The phenotypic states of both species et the end of the 30-year study could not have been predicted at the beginning. Continuous, long-term studies are needed to detect end interpret rare but important events and nonuniform evolutionary change. [ABSTRACT FROM AUTHOR]

Examines the distinguishing features of the modern human skulls. Difference of modern human skulls from species that may have been ancestral to modern human . Possibility of the birth Homo Sapiens hinged on some genetic changes; Identification of those traits that best account for the variation in shape between modern human and other hominid skulls.

Focuses on the discovery of the first hominids. Discovery of Australopithecus afarensis; Diversity of teeth and anatomy of early hominids; Mixed traits of A. afarensis held in defining ideas about the early hominids.

Focuses on the evolutionary divergence of the genome of the natural genetic engineer Agrobacterium tumefaciens C58. Findings of orthology and nucleotide colinearity between the genomes of A. tumefaciens and the plant symbiont Sinorhizobium meliloti; Similarities and differences between the genomes and the plant symbiont; Features of the genome.

Investigates the role of humans as an evolutionary force. Acceleration of evolutionary changes in other species; Exhibition of thinner bodies in fishes; Impact of the industrialization of agriculture, medicine and landscape.

Discusses the morphological evolution of galaxies. Morphological classification of galaxies; Comparison with numerical simulations of galaxy simulation; Nature of many morphologically peculiar galaxies at high redshift levels.

Presents a study that sequenced mouse DNA related to human chromosome 19 to illuminate the function and evolutionary history of both genomes. Evidence for hypothetical genes and identified exons, regulatory elements and candidate genes; Difference between single-copy HSA 19 genes and genes residing in tandem familial clusters.

Outlines a study which proposed protein interaction mapping using large-scale two-hybrid analysis as a way to functionally annotate Caenorhabditis elegans by complete genome sequence. Relevance of protein interaction maps; Method to address the technical problem of cloning multiple genes simultaneously.

Focuses on Archean molecular fossils and the early rise of eukaryotes. Preservation of molecular fossils in shales from the Pilbara Craton, Australia; Hydrocarbon biomarkers indigenous and syngenetic to the Archean shales; Presence of 2alpha-methylhopanes, characteristic of cyanobacteria; Evidence for the early existence of eukaryotes.

Discusses the evolution of dinosaurs. The ascendancy of dinosaurs on land near the end of the Triassic period; Demise at the end of the Cretaceous; Early dinosaurs, visitors by accident; Ornithischians; Sauropodomorphs; Theropods; Evolution of birds from small-bodied predatory dinosaurs; Evolution of feathers, perching, and flight; Evolutionary tempo and morphologic scope; Evolutionary trends and coevolution; Dinosaurs and drifting continents.

Discusses chemical etiology of nucleic acid structure for finding answers to the question of why nature chose the structure type of ribofuranosyl nucleic acids as the molecular basis of life's genetic system. Biological function of ribonucleic acid (RNA) and deoxy ribonucleic acid (DNA); The Watson-Crick mode of base-pairing; Pyranosyl isomer of RNA; Ability of RNA to replicate nonenzymatically; Origin of RNA structure as a consequence of synthetic contingency.

Compares cladistic and stratocladistic methods of inferring evolutionary relationships. Recovery of evolutionary histories using the same data; Use of 550 matrices with varying evolutionary models and fossil records.

Presents the results of sequence data of 18S ribosomal DNA genes from acoels. Simple organization of acoels; Acoels not belonging to the Platyhelminthes, but the earliest divergent Bilateria; Support from other research; Implications of this study; Perceptions of the Cambrian evolutionary explosion.

Presents research which shows that long interspersed nuclear elements (LINE-1s or L1s) insert into transcribed genes and retrotranspose sequences derived from their 3' flanks to new genomic locations. Reverse transcriptase activity; Finding that retrotransposition-competent L1s provide a vehicle to mobilize non-L1 sequences, such as exons or promoters, into existing genes; How they may represent a general mechanism for the evolution of new genes.

States that the serial endosymbiosis theory is a favored model for explaining the origin of mitochondria. Theory which posits that mitochondria are the direct descendants of a bacterial endosymbiont which became established at an early stage in a nucleus-containing host cell; Indications of data; Possibility that the organelle originated at the same time as the nuclear component of the eukaryotic cell.

Reports on discoveries concerning the diets, ecology, and extinction of ancient horses that lived in central Florida. Example of macroevolution that is found in the fossil record of horses; Carbon isotopic and tooth microwear data that provides information on the diet of the horses; Traditional morphological studies of tooth crown height; Species included in the six late Hemphillian Bone Valley horses.

Reports on hox clusters in zebrafish. Function of hox genes to specify cell fate in the anterior-posterior axis of animal embryos; Suggestion that cluster duplication facilitated the genome evolution of vertebrate body plans; Phylogenetic analysis and genetic mapping, which suggest a chromosome doubling event.

Presents research which studied the homeobox gene at the Odysseus (Ods) locus of hybrid male sterility in Drosophila. Role of the homeodomain; Value of studying rapidly evolving homeodomains; Amino acid substitutions in this homeodomain; Speed of its evolution; What drives rapid sequence divergence.

Examines the history and current status of the controversy over the challenging of the tenet of random mutation and the relationship of key experimental findings to neo-Darwinism. Early experiments on mutations in bacteria; Recent evidence for directed mutation; Possible molecular mechanisms for directed mutation; Neo-Darwinian explanations based on random mutation; Experimental evidence for explanations based on random mutations; More.

Presents a study of the evolutionary relationships of the onychophorans (velvet worms) and the monophyly of the arthropods. Cladistic analyses of 12S ribosomal RNA sequences' indications that arthropods are monophyletic and include the onychophorans; Myriapods (millipedes and centipedes) forming a sister group to all other assemblages, whereas crustaceans (shrimps and lobsters) and hexapods (insects) form a well-supported monophyletic group.

Describes a direct study of hybridization, or interbreeding of species, of populations of Darwin's finches through pedigree analysis. Incidence of hybridization in general populations; Genetic and evolutionary consequences of hybridization; Description of birds studied on Galapagos archipelago island; Fitness consequences of hybridization; Causes of hybrid superiority; Questions about designations of species for three study groups of Darwin's finches.

Presents an analysis of epsilon-globin gene sequences from a number of primates and other eutherian mammals to determine the relationship between the bat suborders Megachiroptera (megabats) and Microchiroptera (microbats). Phylogenetic analysis of sequences; Results of parsimony analysis which supports the monophyly of bats; Similarities of derived nucleotides.

Discusses a method which provides criteria by which the range of possible outcomes of evolutionary social behavior can be narrowed, and to specify the conditions for their occurrence. Hominid socio-ecological context; Sexual strategy and distribution states; Australopithecus afarensis.

Presents research which identified two major trilobite faunas with disjunct temporal diversity trends in the Ordovician period. Traits of the Ibex Fauna and the Whiterock Fauna; Conclusion that trilobites were participants in the great Ordovician radiations; Extinction patterns at the end of the Ordovician period.

Presents research which formulated a model of tRNA evolution. Traits of the transfer RNA (tRNA) multigene family; Addition of isoacceptors to tRNA repertoire; Test of proposed model; Use of Escherichia coli; Insertion of threonine at threonine codons.

Presents research which questions the use of Late Pleistocene glaciations for determination of speciation for North American vertebrates. Divergence value for Late Pleistocene Origins model; Divergence value for 35 songbird species; Suggestion of protracted history of speciation events for North American songbirds over five million years.

Presents research which asserts that the discovery of a STAT (signal transducer and activator of transcription) in Drosophila and in Dictyostelium discoideum implies an ancient evolutionary origin for this set of proteins. Mechanism of activation; STAT functions and origin; STAT DNA binding and transcriptional activation; Activation-inactivation cycle; Trans-activation by STATs; Conclusion.

Reports that a population of RNA molecules that catalyze the template-directed ligation of RNA substrates was made to evolve in continuous manner in the test tube. How the catalysis was achieved; Improvement in both the catalytic rate and amplification rate of the RNAs.

Looks at macroevolutionary trends in host use as they relate to insects on plants. The macroevolutionary importance of plant chemistry on herbivore host shifts being critical to the understanding of insect-plant interactions; Reconstruction of the molecular phylogenies of the ancient and speciose Blepharida-Bursera system; Historical patterns of host shifts relating to host chemical similarity.

Reports on the rate of evolution in natural populations of guppies (Poecilia reticulata). Rate of evolution of age and size under natural selection similar to those under artificial selection; Rate of evolution of male and female traits; Implications.

Reports paleontological and chronological evidence to demonstrate the evolution of the land snail Cerion on the Bahamian island of Great Inagua. Three species of the snail presently on the island; Suggestion that the invading snail Cerion rubicundum gradually gained dominance over the native snail Cerion excelsior during a period of 15,000 to 20,000 years; Methods used to arrive at the conclusions.