Question

scientists compile many pieces of evidence to infer evolutionary relationships. here is one such piece of evidence.
elongation factor 2 is a protein involved in translating mrna into proteins. it is found in all organisms and contains between 669 and 858 amino acids. this table shows the number of amino acids in elongation factor 2 that are identical between three different organisms: cows, escherichia coli bacteria, and pyrobaculum islandicum archaea.
the number of identical amino acids in elongation factor 2 between pairs of organisms
cows and e. coli bacteria: 192
p. islandicum archaea and e. coli bacteria: 177
p. islandicum archaea and cows: 293
how does this evidence support the claim that archaea are more closely related to cows than to bacteria? complete the paragraph.
p. islandicum archaea and cows have similarities in their elongation factor 2 amino acid sequences than p. islandicum archaea and e. coli bacteria have. this suggests that p. islandicum archaea and have less similar dna and evolved from a more common ancestor.

Explanation:

• For the first blank: Compare the number of identical amino acids. \(293\) (cows - \(P\). \(islandicum\) archaea) is greater than \(177\) ( \(P\). \(islandicum\) archaea - \(E\). \(coli\) bacteria), so more.
• For the second blank: Since we are comparing \(P\). \(islandicum\) archaea with \(E\). \(coli\) bacteria (as the claim is about archaea - cows vs archaea - bacteria), \(E\). \(coli\) bacteria.
• For the third blank: More similarity in a protein (which is coded by DNA) implies a more recent common ancestor.

Answer:

• First blank: more
• Second blank: \(E\). \(coli\) bacteria
• Third blank: recent