Category: Uncategorized

WIDESPREAD LOSS. "Even animals and plants, the eukaryotic kingdoms that seem to be the least prone to gene loss, have lost about 20% of the putative ancestral genes identified in the unicellular Naegleria. Collectively, these findings imply that the genome of the LECA was at least as complex as the genomes of typical extant free-living unicellular eukaryotes." (LECA = last eukaryotic common ancestor). http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

PATHWAY? "Death is not the waste of life it sometimes seems, but the pathway through which energy flows through virtual life and through its fractals." (Whatever that means). https://muse.jhu.edu/chapter/275813 View in LinkedIn

SNAKES AND LADDERS. "Given the fractions of conserved and lineage-specific genes in modern archaeal genomes, this translates into approximately 2,500 genes in the ancestral genome, which is a larger genome than most of the extant archaea possess. The reconstructed pattern of gene loss and gain in archaea is non-trivial: there seems to have been some net gene gain at the base of each of the major archaeal branches that was almost invariably followed by substantial gene loss...this could be a general pattern of genome evolution." http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

DEATH AS AN ADAPTATION TO LIFE. "Instead of imagining death as the antithesis of life, death must be appreciated as an evolving part of life and an adaptation to life." https://muse.jhu.edu/chapter/275814 View in LinkedIn

ANOTHER EXEMPLAR. "The most compelling evidence of the dominance of genome reduction and simplification was obtained through the reconstruction of the genomic evolution of archaea that almost exclusively are free-living organisms. The latest ML reconstruction based on a comparative analysis of 120 archaeal genomes traced between 1,400 and 1,800 gene families to the last common ancestor of the extant archaea." (ML = maximum likelihood methods). http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

CONSTRAINTS ON REDUCTIONS. "Certainly, the evolution of the genomes of parasites, symbionts and commensals is not a one-way path of reduction. On the contrary, the reduction ratchet is constrained by the advantages of retaining certain metabolic pathways that complement the host metabolism." http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

TWO METHODS. "Genome reduction apparently occurs in two distinct and distinguishable manners, i.e. either via a neutral ratchet of genetic material loss or by adaptive genome streamlining." http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

NET BALANCE. "The genes apparently have been lost in a stepwise manner, with substantial loss associated with each internal branch of the tree and most but not all of the individual species. These losses were only to a small extent offset by inferred gain of new genes." http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

STREAMLINING EXEMPLAR. "One of the best-characterized cases involves the Lactobacillales, a group of Gram-positive bacteria that is extremely common in a variety of animal- and plant-associated habitats. A maximum parsimony reconstruction revealed substantial gene loss, from ∼3,000 genes in the common ancestor of Bacilli to ∼1,300–1,800 genes in various Lactobacilli species." http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

OUTSOURCING LIFESTYLES. "Beyond parasites and symbionts, reductive evolution was observed in several groups of organisms that evolved a commensal life style." http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn