Assertion: common ancestor | /r/AtLocation | the precambrian
Facets:
Source sentences:
text: 6,331 groups of genes common to all living animals have been identified; these may have arisen from a single common ancestor that lived 650 million years ago in the Precambrian.
text: 6,331 genes common to all living animals have been identified; these may have arisen from a single common ancestor that lived 650 million years ago in the Precambrian.