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GRAND SCHEME. "Quantitatively, the evolution of genomes appears to be dominated by reduction and simplification, punctuated by episodes of complexification." https://lnkd.in/egqWFZp View in LinkedIn

VIRUSES are ancient creatures in the Grey Zone are so simple they were not considered alive until recently. Traditionally, we have wrongly associated them only with diseases, which is actually a minor part of the picture. These remarkable creatures have played a key role in building the genomes of all life forms by their promiscuous RNA and DNA sharing, and shaping the geosphere. View in LinkedIn

MOLECULAR CLOCK. "Reconstructions of genome evolution in both prokaryotes and eukaryotes indicate that the loss of genes and introns typically occurs roughly proportionally to time, thus conforming with a form of genomic molecular clock." https://lnkd.in/egqWFZp View in LinkedIn

QUIZ. "What has a tiny shell, it's invisible to the naked eye, it affects the Earth's climate and causes cancer? It's a virus. Viruses kill half the bacteria in the ocean every day. And they invade a microbe host 10 trillion times a second around the world. Wow." https://lnkd.in/eWe4ADF View in LinkedIn

GENE AND INTRON REDUCTION. "The complex archaeal ancestor and the intron-rich ancestor of eukaryotes. In both cases, evolution in most of the lineages was apparently dominated by extensive loss of genes and introns, respectively." https://lnkd.in/egqWFZp View in LinkedIn

WE TRANSITION from horizontal gene transfer and attendant problems in the case of antibiotic resistance, or attendant advantages in the case of genetic refreshing, to the great agents of change, namely, viruses and bacteria. These remarkable ancient creatures lived long before the newcomer Homo sapiens, and their evolution streamlined and outsourced their genomes to an advanced simplicity. View in LinkedIn

THIS IS NOT THE PLACE to go into a detailed discussion of GMOs. I have used them to illustrate the practical considerations of horizontal gene transfer, along with antibiotic resistance. Remember the Saxon King Cnut (995-1035) who tested his powers in the East Anglian Wash by commanding the tide not to rise? https://lnkd.in/eMbpfsJ View in LinkedIn

SOIL RESISTANCE POOL. "The reuse of treated wastewater (TWW) for irrigation is a practical solution for overcoming water scarcity, especially in arid and semiarid regions of the world. One such risk stems from the fact that TWW irrigation may increase antibiotic resistance (AR) levels in soil bacteria, potentially contributing to the global propagation of clinical AR." https://lnkd.in/e2B99ZZ View in LinkedIn

SO ENDS this first weekend on reductive evolution. It is becoming clear that evolution has extended periods of gene streamlining and loss interspersed by periods of vigorous gene amplification and innovation as new life forms develop. And among those species who adopt a parasitic or symbiotic lifestyle, there can be massive gene loss. This is contrary to the simple paradigm of life inexorably becoming more complex with time. View in LinkedIn

CRYSTALLIZABLE, INFECTIVE, REPRODUCTIVE. Viruses contain DNA and RNA, and can by crystallized. Because of the latter fact, and they they are genetically streamlined and outsource to the machinery of host cells, many consider that they are not living. Like prions, viruses co-opt the cellular machinery to exist. View in LinkedIn