Polygenist hybrid predictions kept failing and were revised until Darwinian theory displaced them

Evidence

The first revision was to insist that hybrids themselves would be infertile; later that more “distant” groups are much more likely to be infertile than more “proximate” ones (Broca 1860/1950; cf. Young 1995: 18), When counter-evidence quickly emerged, predictions were revised to the longer-term view that hybrid offspring eventually - over a number of (unspecified) generations ~ would degenerate and ultimately die out (Knox 1862; cf. Broca 1860/1950). The failure of this prediction to materiali ze coincided more or less with the demise of polygenic theory in the face of Darwinian evolution, on one hand, and Darwinist-prompt ed eugenics, on the other. — David Theo Goldberg, The Racial State, 17

Categorization

• SHARE: Anthropology/race-theory friend would enjoy the pattern: an unfalsifiable theory moving goalposts from infertility to eventual degeneration rather than conceding.
• XREF: connects to: Late-nineteenth-century Darwinian race science underpinned homo islamicus typologies

Related

• Mixed-race offspring directly contradicted the polygenist claim that races are separate species (similarity 0.84)
• Hybridity theory presupposes pure races just as nineteenth-century race science did (similarity 0.83)
• Polygenesis fell just as a new race theory rose to replace it. (similarity 0.82)
• Ancient notions of race as biology do not match reality (similarity 0.80)
• Late-nineteenth-century Darwinian race science underpinned homo islamicus typologies (similarity 0.80)
• Pre-Adamism’s polygenism relegated Africans to animal proximity in European thought (similarity 0.79)
• Scientific discourse on race has always intertwined race and sex difference. (similarity 0.78)
• Modern evolutionary biology replaced fixed racial hierarchy with dual evolution by nature and nurture. (similarity 0.78)