Never. I donât wear 17Â½, which is fairly humongous, but an average-ish 16Â½. Now, you could be a hard-bodied linebacker, or you could be a sumo-sized layabout; there are many different body types, so buying shirts just by neck size and arm length is necessarily inexact. One has to be aware of the cut of the brand. Traditional American shirts, like those sold by Brooks Brothers, are very blousy.
A clade is a group of species that includes an ancestral species and all of its descendants (Figures 3, 4). Clades (also called monophyletic groups), like species, are formed by the process of descent with modification. A phylogeny is a pattern of common ancestry reflecting this evolutionary process.
Image caption: A clade is a grouping that includes a common ancestor and all the descendants (living and extinct) of that ancestor. Using a phylogeny, it is easy to tell if a group of lineages forms a clade. Imagine clipping a single branch off the phylogeny  all of the organisms on that pruned branch make up a clade.