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REPURPOSING. “Duplication of genetic material immediately leads to genetic redundancy, whereby gene copies can subsequently diverge and evolve toward novel or altered functionality. In plant pathogenic fungi and oomycetes, the expansion of a plethora of gene families such as peptidases, glycoside hydrolases, kinases, or transporters has been implicated in the pathogenic lifestyle.” https://lnkd.in/eC8eb-V View in LinkedIn

GENERATING DIVERSITY. “Chromosomal rearrangements induce a multitude of genomic variations such as duplications, deletions, inversions, and translocations, leading to the gain or loss of genomic material and are observed in both sexual and asexual fungi.” https://lnkd.in/eC8eb-V View in LinkedIn

REDUNDANCY. “The wheat pathogen Mycosphaerella graminicola contains 21 chromosomes of which eight are conditionally dispensable. Particularly, the dispensable chromosomes display a high frequency of chromosomal rearrangements and, in the absence of strong positive selection, have been hypothesized to drive divergence.” https://lnkd.in/eC8eb-V View in LinkedIn

SO ENDS this first part on the evolutionary impact of viruses. They do not fit into the relatively tidy box that Victorian biologists constructed of the world. They defy the idea of species. They frustrate definitions of life. Their form is pure Euclidian geometry. They shimmer at the edge of our definitions of life. They mutate and reproduce at extraordinary rates. And contrary to the old picture, few are pathogenic and many have played an integral role in the evolution of life on this planet. A radical new picture. View in LinkedIn

VIRUSES AND ALL TRANSITIONS. "We can then see that viruses were involved in most all major transitions of host biology in evolution. This will likely seem an overstated or even preposterous position to most readers. How could genetic parasites (viruses) be providing such fundamental capacity for host evolution? And why would they do so?" http://onlinelibrary.wiley.com/doi/10.1111/apm.12485/full View in LinkedIn

CONTROLLING ADVERSE EFFECTS. “Transposable elements are powerful facilitators of evolution but may at the same time be harmful to the individual organism. Therefore, several complementary mechanisms to control transposable element activity have evolved. In many fungi, duplicated DNA is actively mutated by a process called repeat-induced point mutation.” https://lnkd.in/eC8eb-V View in LinkedIn

TWO SIDES OF THE COIN. “Due to the deleterious effect of most genomic rearrangements, the detection and repair of double-strand DNA breaks are tightly regulated. Not surprisingly, mutations affecting central components of double-strand DNA break repair pathways are responsible for an increase in genomic rearrangements.” https://lnkd.in/eC8eb-V View in LinkedIn

INDUCED CODE VARIETY. “Repair of double-strand DNA breaks play important roles in fostering genomic diversity during meiotic and mitotic recombination, and errors during these processes can promote extensive genomic rearrangements.” https://lnkd.in/eC8eb-V View in LinkedIn

DIVERSE MECHANISMS. “In addition to rare, hidden, cycles of sexual reproduction that involve two opposite mating types, non-conventional modes of reproduction are also observed in presumed asexual species.” https://lnkd.in/eC8eb-V View in LinkedIn

USEFUL SUBSTRATES. “The high abundance and their high levels of similarity make transposable elements and other repetitive sequences obvious ectopic substrates in naturally occurring double-strand DNA break repair pathways. Moreover, increasing evidence suggests mobilization of transposable elements by environmental stresses leading to genome evolution.” https://lnkd.in/eC8eb-V View in LinkedIn