The theory of common descent states that all living organisms are descendants of a single ancestor. Phylogenetic trees and cladograms are often used to hypothesize the evolution of various organisms and shared common descent.
Hope that helped you:)
I'm not sure if this is what you were looking for but I hope it helps :)
Other surfaces that separate body cavities from the outside environment are lined by simple squamous, columnar, or pseudostratified epithelial cells. Other epithelial cells line the insides of the lungs, the gastrointestinal tract, the reproductive and urinary tracts, and make up the exocrine and endocrine glands.
answer:
Skin
Skin
