Question

A BLAST search using the amino acid sequence of human parathyroid hormone (PTH) against the protein and DNA sequence databases returned close homologs in many vertebrate species ranging from primates to fish, but no sequence homologs in bacteria, archaea, plants, fungi, slime moulds, arthropods or nematodes. With reference to the tree of life shown above, where do you think PTH evolved? Explain your answer.

Answer 1

PTH hormone was evolved during the origin of vertebrates. It ca be found from early vertebrates like fish to more advanced vertebrates like human. In the life tree shown above the branch where PTH has evolved cannot be indicated properly. The life tree indicates tat Animals have diverged from fungi, but no further division of animals have been given in the tree. All animals do not have PTH such as insects or nematodes. The branching of animal kingdom where verterbrate have diverged from the other animals should be the proper place where PTH have evolved.