These pedogenic gravels were probably formed in different times and sites within the soil matrix, which strongly supports the idea of their use as indicators of soil
polygenesis. On the other hand, for lithopedogenic gravels, mostly comprising Proterozoic shale and quartzite fragments, the impregnation by soil-derived oxides may have spanned longer times and cycles of soil formation.
Theories about multiple origins for human beings, the lines developing in parallel in different regions ("
polygenesis"), do crop up from time to time.
The problem became even more complicated when a fierce controversy developed over the question of monogenesis or
polygenesis. Was mankind created only once, or had there been several successive creations of man?
The egalitarian dynamic latent in the ideal of a humanity united by reason was undermined by the placing of humans squarely in the natural world, to be subdivided and ranked according to the same principles of speciation as the animal kingdom; in nineteenth-century France especially, ideas of
polygenesis were widely accepted, enlarging the potential for ideologies of racial subordination.
One such area of science was
polygenesis, which gave credence to Black Africans as inherently inferior.
While her descriptions of
polygenesis, monogenesis, and polycentrism are well-described, her account of human evolution smacks of early twentieth-century evolutionary theory rather than contemporary theory.
Slavery's apologists often rested their argument on the theory of
polygenesis, which held that the races were created separately--a view that was also held by many anti-slavery activists who still saw blacks as inferior, despite their arguments against the slave system.
His study on "Slavery's Champions Stood at Odds:
Polygenesis and the Defense of Slavery" was selected by a committee at the Richards Civil War Era Center at the Pennsylvania State University.
And attendant to such claims, Kidd points out, were ideas about monogenesis and
polygenesis, and he deftly shows how these arguments impacted nineteenth century discussions about slavery and abolitionism (particularly in the United States), for example, and about the contested claims of Jesus' "race" and "ethnicity." In addition, Kidd contextualizes the forms of "racialised religion" (203) that emerged during the nineteenth century (e.g., Mormonism and Theosophy) and twentieth century (e.g., Christian Identity Movement), and locates these groups, not as independent Protestant offshoots necessarily, but into the stream of biblical interpretation through racialized lenses.
For example, Sandor Gilman draws radical conclusions from half a sentence in Deronda: 'And one man differs from another, as we all differ from the Bosjesman', (2) claiming that this assumes 'a polygenetic view of race', (3)
polygenesis being the belief that races have evolved from more than one set of ancestors so that they are seen as belonging to different lineages.