Nov. 21 (UPI) --The research is clear, the physiological complexity that makes modern humans -- and other mammals -- unique from simpler species is a product of gene regulation, not genet quantity.

Tunicates, strange tube-like creatures in various colors, shapes and sizes, are found on ship hulls, larger seashells, pier pilings, seafloors and the backs of enormous crabs in oceans worldwide.

(This article forms a part of the Science for All newsletter that takes the jargon out of science and puts the fun in! Subscribe now!) They are a species of marine invertebrates with an evolutionary ...

The closest relatives of vertebrates are the urochordates (tunicates, or sea squirts) and cephalochordates (the superficially fish-like lancelet). More distant on the evolutionary tree lie the ...