A record of igneous evolution in Elysium, a major martian volcanic province

A major knowledge gap exists on how eruptive compositions of a single martian volcanic province change over time. Here we seek to fill that gap by assessing the compositional evolution of Elysium, a major martian volcanic province. A unique geochemical signature overlaps with the southeastern flows of this volcano, which provides the context for this study of variability of martian magmatism. The southeastern lava fields of Elysium Planitia show distinct chemistry in the shallow subsurface (down to several decimeters) relative to the rest of the martian mid-to-low latitudes (average crust) and flows in northwest Elysium. By impact crater counting chronology we estimated the age of the southeastern province to be 0.85 ± 0.08 Ga younger than the northwestern fields. This study of the geochemical and temporal differences between the NW and SE Elysium lava fields is the first to demonstrate compositional variation within a single volcanic province on Mars. We interpret the geochemical and temporal differences between the SE and NW lava fields to be consistent with primary magmatic processes, such as mantle heterogeneity or change in depth of melt formation within the martian mantle due to crustal loading

Initial sequence of the chimpanzee genome and comparison with the human genome

Here we present a draft genome sequence of the common chimpanzee (Pan troglodytes). Through comparison with the human genome, we have generated a largely complete catalogue of the genetic differences that have accumulated since the human and chimpanzee species diverged from our common ancestor, constituting approximately thirty-five million single-nucleotide changes, five million insertion/deletion events, and various chromosomal rearrangements. We use this catalogue to explore the magnitude and regional variation of mutational forces shaping these two genomes, and the strength of positive and negative selection acting on their genes. In particular, we find that the patterns of evolution in human and chimpanzee protein-coding genes are highly correlated and dominated by the fixation of neutral and slightly deleterious alleles. We also use the chimpanzee genome as an outgroup to investigate human population genetics and identify signatures of selective sweeps in recent human evolution

The Modern Career of the Oldest Profession and the Social Embeddedness of Metaphors

Metaphors are elementary particles of meaningfulness, serving as cognitive resources for framing social problems or social movement narratives. This article presents a diachronic analysis of a metaphor synthesizing insights from cultural sociology and conceptual metaphor theory (CMT), an interdisciplinary neuroscientific program with robust empirical findings for how meanings change over time. I track the diffusion of ‘the most ancient’ metaphor for prostitution through publications on both sides of the Atlantic from its coinage by Rudyard Kipling in 1888. I explain the puzzle of its persistent polysemy by its embeddedness in three discursive communities: occupational professionals; social movements demanding state action against white slavery; and journalists, writers and cultured readers. These competing uses explain the paradox of how a metaphor about prostitution’s timelessness became a convention at the very movement that prostitution’s abolition seemed possible. While this single metaphor was used to express multiple opinions about prostitution’s inevitability, it shored up the ontological status of prostitution, a concept that contemporary researchers still struggle to unpack or displace. The diachronic analysis by which cultural categories are juxtaposed and reified is one of the insights of CMT for social cognition, with implications for sociological analysis of narratives, tropes and discourses