Question

Multiple Choice and Explain:

Swine A Human Nebraska 92 Scotland 94 Ehime 80 Mongolia 91 CHR 8 isconsin 98 Mongolia 85 USSR 77 Leningrad 54 Kiev 79 New Jersey 76 100 linois 63 Fort Monmouth 47 Wisconsin 61 Mongolia 88 100 PR 34 Alma Ata 84 Tokyo 67 NWS 33 WSN 33 St-Hyacinthe 90 lowa 30 91 100 Cambridge 39 100 South Carolina 1918 Swine Nebraska 92 St-Hyacinthe 91 Wisconsin 98 80 Human New Jersey 76 Scotland 94 Mongolia 91 Suita 89 Ilinois 63 Wisconsin 61 CHR 83 ia 85 Kiev 79 Leningrad 54Mongolia 88 USSR 77 00IPR 34 Fort Monmouth 4 Alma Ata 84 39 SN 33 Tokyo 67NwS 33 100 100 lowa 30 South Carolina 1918 M. J. Gibbs, J. S. Armstrong, A. J. Gibbs. Recombination in the hemaglutinin gene of the 1918 "Spanish flu". Science 293, 1842 (2001) 6) The trees show the phylogeny estimated for the same mammalian H1 influenzas based on portions of the hemaglutinin genes. Tree A was estimated from bases 310-870 whereas tree B was estimated from bases 1070-1650. Under the assumption that these trees are correctly rooted, how does this result support the inference that the Soutlh Carolina 1918 strain (the only exemplar from the 1918 flu pandemic) arose from recombination between a human and a swine virus? a) The fact that the South Carolina 1918 strain is near the root (base) of both trees suggests that it is of mixed identity. b) The fact that the South Carolina 1918 strain is more closely related to the swine strains in tree A but to the human strains in tree B c) The fact that the South Carolina 1918 strain is a direct ancestor of all the swine strains in tree A but was isolated from a human d) The fact that the South Carolina 1918 strain is more closely related to the Iowa 30 swine strain than to the Scotland 94 human strain in both trees

Answer 1

OPTION (B) The fact that the South Carolina 1918 strain is more closely related to the swine strains in tree A but to the human strains in tree B

Consider the case of HIV/AIDS, where phylogenies have been used to identify the source of the virus, to date the onset of the epidemic, to detect viral recombination, to track viral evolution within a patient, and to identify modes of potential transmission .Phylogenetic analysis was even used to solve a murder case involving HIV. Yet “tree thinking” remains widely practiced only by professional evolutionary biologists. This is a particular cause for concern at a time when the teaching of evolution is being challenged, because evolutionary trees serve not only as tools for biological researchers across disciplines but also as the main framework within which evidence for evolution is evaluated