The ultimate aim is to use sequence divergence as an indication of homology, defined here as descent from common ancestry (this is controversial and will be discussed further below).
It is well established that secondary plastids in many 'chromalveolate' taxa are derived from red algal endosymbiont(s), but the origin and evolutionary history of 'chromalveolate' plastids are more controversial than those of green algal ancestry [ 10- 14].
Thus intellectual ancestry is always more controversial than biological inheritance, and the mere presence or absence of thinkers in particular developmental accounts is not necessarily an accurate indication of their actual historical role or importance.
The study of ancestry and genetics is a highly controversial subject [7], [8], [9].
The ancestry of the latter species remains controversial, with a probable diffuse domestication process featuring several wild species that contributed to its current genetic pool (see Zeder 2006).
In healthcare policy making, using 'genetic explanations' for ancestry-based provision of services is controversial at the very least.
Of note, ancestries based on sequences are inherently controversial [ 24], and the same general objections to species phylogenetic studies likely apply to our somatic cell trees.
It is controversial whether the skeptics Diogenes has in mind claim this ancestry.
The relative importance of genetic ancestry and social factors in health and disease is still controversial, and likely involves interactions between both elements [23], [24].
As black social scientist E. Franklin Frazier notes, in a controversial study of the black bourgeoisie in the 1950s, mulattoes (blacks with white ancestry, often referred to as "biracial" today) have lived a privileged existence when compared with their "pure black" counterparts since chattel slavery.
Through these marriages, such as that of Alfonso VI of León and Castile and Zaida of Seville, it is believed that most European royalty can trace their ancestry back to the family of the prophet Muhammad, though this remains controversial.
