Primitive life is arduous and exhausting, especially when working hard to upgrade the living accommodations from a simple survival shelter to eventually a comfortable adobe hut.

For this, scientists use something called an "outgroup", a living descendant that still shares many of the ancestor's primitive traits. So we need a living jawless fish, like a lamprey.

Flinders University researchers have studied the musky rat-kangaroo (Hypsiprymnodon moschatus), a diminutive marsupial that weighs only 500 grams but is the last living representative of its family ...