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ANTI-RECOMBINATION DRIVES SEX CHROMOSOMES. "The accumulation of sexually antagonistic mutations on protosex chromosomes selects for a loss of recombination and sets in motion the evolutionary processes generating heteromorphic sex chromosomes." http://www.pnas.org/content/110/16/6453.full View in LinkedIn

TRANSFORMATION. "Sex chromosomes originate from autosomes." https://lnkd.in/g9djQYs View in LinkedIn

BURST OF EVOLUTION. "The presence of genes for male characters on the Y, but not the X, also indirectly suggests that antagonistic selection must have acted. When there has been a recent transposition of an autosomal gene onto the Y chromosome, if sufficient intraspecies variability is available, tests for selection based on comparisons of polymorphism and divergence could be used to ask whether the locus has experienced a burst of adaptive evolution." http://www.nature.com/hdy/journal/v95/n2/full/6800697a.html View in LinkedIn

RACE TO THE TOP. "If Y-linked genes are incessantly evolving to improve male function and compete with other male genotypes, the changes may drive the evolution of recombination suppression, and thus recombination modifiers may also spread, some of which may themselves be on the Y (for instance, inversions)." http://www.nature.com/hdy/journal/v95/n2/full/6800697a.html View in LinkedIn

SO ENDS this first weekend review of new thinking about the old concept of one pathogen one disease; there are some today who advocate an ecological viewpoint, where a web of interacting microorganisms cause a disease progression, and this has considerable biological support. The implications of this new thinking are profound. View in LinkedIn

WEB OF INTERACTIONS. “In addition, microorganisms interact with each other. Antagonistic and mutualistic behaviors have evolved as adaptations to living in microbial communities.” https://lnkd.in/gEfVGaC View in LinkedIn

PATHOGEN SELECTION PRESSURES. “ The ecosystems within which pathogens evolve are defined by their abiotic and biotic dimensions, including both host and vector populations. Pathogens must adapt to selective pressures associated with these complex ecosystems, in particular to both host and vector defense mechanisms as well as to any environmental fluctuations impacting on their survival and/or dispersal outside of hosts or vectors.” https://lnkd.in/gEfVGaC View in LinkedIn

SNAPSHOT OF EVOLUTION. “The third goal is to understand the impact of microbial communities on the persistence, transmission, and evolution of pathogens. In particular, to elucidate the spatio-temporal dynamics of these communities, the ecological interactions between microorganisms within communities, as well as the evolutionary forces at play (mutation, selection and gene flow)—especially when it comes to pathogen survival, extinction or dispersal.” https://lnkd.in/gEfVGaC View in LinkedIn

SEX CHROMOSOME DIVERSITY. "We identify over a dozen different sex chromosome configurations, and the small dot chromosome is repeatedly used as the sex chromosome, which presumably reflects the ancestral karyotype of higher Diptera." (Winged insects). https://lnkd.in/dX2rADH View in LinkedIn

MISSING THE DYNAMIC PICTURE. “Because metagenomic DNA-based analyses cannot differentiate between expressed and non-expressed genes, these approaches fail to reflect the actual activity or dynamics of microbial communities.” https://lnkd.in/gEfVGaC View in LinkedIn