One evolutionary idea is that the number of amino acids differences in a similar protein from different species can be used as an evolutionary clock. The rate of amino acid substitution varies among proteins as shown in the following table;Protein changes per protein per billion Year;Fibronectin 9.0;Phospholipase A2 1.9;Cytochrome b5 0.45;Lactate Dehidrogenase 0.34;Cytochrome c 0.22;Histone 4 0.01;a) what is the average rate of amino acid substitution among all the proteins shown?;b) on average, how long would it take to make one change in histone H4? would this serve as a good evolutionary clock?;c)In the time it takes for one change in cytochrome b5, how many changes would we expect to find in fibronectin?;d) In the two million years' time that horses have been differentiated from donkeys, how many amino acid substitutions would be found altogether in these six proteins?
Paper#18315 | Written in 18-Jul-2015Price : $32