derived by descent from
derived from ancestral fusion of
false
Chris Mungall
A has_fused_element B does not imply that A has_part some B: rather than A has_part some B', where B' that has some evolutionary relationship to B.
Chris Mungall
has fused element
x has_fused_element y iff: there exists some z : x has_part z, z homologous_to y, and y is a distinct element, the boundary between x and z is largely fiat
requires discussion