Astudy published in 2000 sequenced part of the mitochondrial cytochrome b gene from 61 brown bears from two sites in alaska. one population of brown bears lives on the coastal mainland of alaska, while a separate population lives on the abc islands in southeastern alaska. mainland and abc brown bears differ by 11 fixed nucleotide substitutions in the cytochrome b gene. this suggests that the two brown bear populations represent genetically unique clades. the researchers compared the cytochrome b sequences of the two clades of alaskan brown bears to those of 55 polar bears. the analysis showed that polar bears and abc brown bears differ at only three nucleotides in this gene, whereas polar bears and mainland brown bears had more differences. based on the results of the 2000 study, how should the portion of the tree extending from branch point 7 be altered?

Which of the following scenarios is an example of the bottleneck effect? answers a in south africa, much of the afrikaner population is descended from a small number of dutch colonists. in this population, this is an unusually high frequency of pseudoxanthoma elasticum (pxe), an elastic tissue disorder. b four white-tailed deer are introduced to a park in finland. thirty years after their introduction scientists compare the genes in the population and find that there is no variation. c during the industrial revolution, london's air became filled with soot. as a result, birds started eating more of the lighter moths because they were easier to spot than their darker counterparts. over time, the moth population changed so that there were more darker moths than lighter ones. d 10% of the population of american alligators in an area have the recessive trait albinism. a massive flood results in the death of 80% of the population. of the remaining population, 60% have the recessive trait of albinism.

Name the glands associated with human digestive system

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils