Supporters of the Universality Hypothesis claim that many facial expressions are innate and have roots in evolutionary ancestors.
It is also thought to have directly led to the development of tools, not just in humans or their evolutionary ancestors, but other primates as well.
Reptiles and mammals have been placed into clades, which are groups that include a common evolutionary ancestor and all of its descendants.
It is also found at all levels, not just among our nearest evolutionary ancestors, the monkeys and the apes.
"Perhaps we'll find large and related types of the same evolutionary ancestors for you, Liu."
Six classes of ribosomal protection genes/proteins have been found, all with high sequence homology, suggesting a common evolutionary ancestor.
The brain was "engineered" as a dynamic neural computer that calculated the strategies of survival and reproduction needed by our evolutionary ancestors.
This theory states that an animal's embryonic development follows exactly the same sequence as the sequence of its evolutionary ancestors.
This hypothetical ancestor might then provide clues about what to look for in an actual evolutionary ancestor.
In evolutionary theory, species which share an evolutionary ancestor are said to be of common descent.