id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-015503-j99cgsjt	Tang, Xiaolu	On the origin and continuing evolution of SARS-CoV-2	2020-03-03		.txt	text/plain	5243	292	59	Although we found only 4% variability in genomic nucleotides between SARS-CoV-2 and a bat SARS-related coronavirus (SARSr-CoV; RaTG13), the difference at neutral sites was 17%, suggesting the divergence between the two viruses is much larger than previously estimated. Our results suggest that the development of new variations in functional sites in the receptor-binding domain (RBD) of the spike seen in SARS-CoV-2 and viruses from pangolin SARSr-CoVs are likely caused by mutations and natural selection besides recombination. Population genetic analyses of 103 SARS-CoV-2 genomes indicated that these viruses evolved into two major types (designated L and S), that are well defined by two different SNPs that show nearly complete linkage across the viral strains sequenced to date. Further, the genomic sequences of SARS-CoV-2 viruses isolated from a number of patients share sequence identity higher than 99.9%, suggesting a very recent host shift into humans [1] [2] [3] .	./cache/cord-015503-j99cgsjt.txt	./txt/cord-015503-j99cgsjt.txt