Question

Please explain your response ???. Thank you! ?

I. Briefly describe three pieces of evidence from the paper that you read for lab this week (Storz, 2007), that support natural selection as the mechanism leading to deer mice adapting to high altitude environments.

Answer 1

Life has adapted to all kinds of environmental conditions on earth. Archeae, a class of Bacteria, which is known to be adapted for earth's most extreme environmental conditions. There are many examples of life forms which are adapted itself in extreme environment. One such example is Deer mice, which is adapted to live at high altitude environments. We may get some evidences that support natural selection when we took mice to high and low altitude environments. One such study is disscussed here in which researchers took the deer mice to high and low altitude environments and after rearing the lab, measured population difference in the mice as well as their offsprings. Study shows the difference were associated with changes in the expression of no. of a genes involved in energy metabolism, muscle plasticity, vascular development and cellular stress.

Further, the population analysis of a two locus alpha globin polymorphism that underlies physiological adaptation to high altitude deer mice. When DNA sequence is surveyed, variations in the duplicated alpha globin genes of deer mice from high altitude and low altitude localities 1) to identify the specific mutations that may be responsible for the divergent fine tuning of haemoglobin function and 2) to test whether the genes exhibit the expected signature of diversifying selection between population that inhabit different elevational Zones. Results demonstrate that functionally distinct protein alleles are maintained as the long term balanced polymorphism and that adaptive modifications of haemoglobin function are produced by the independent as joint effects of five amino acid mutations that modulate oxygen binding affinity.