Serfs were the slaves of feudal Europe, Slavs were the slaves of the Ottoman empire, and to fuel the fortunes of capitalists in the new world, Africans were captured and became the new labor force as well as a commodity, building the fortunes of the new world. The theory of evolution helped persuade the new world that slavery was ok. It developed, not on it's own, not as a purely scientific quest, but to defend slavery and the rights of wealthy slave owners. And it is their wealth that funded it, to defuse the accusations of abolitionists.

Pretty simple, Linda... volumes upon volumes of historical evidence and writings about it.

<img src="http://herballure.com/ForumExtras/Images/uymtnldunb.jpg">
Anthony Benezet, Some Historical Account of Guinea, London, 1788


"Take up the White Man's burden—
Send forth the best ye breed—
Go bind your sons to exile
To serve your captives' need;
To wait in heavy harness,
On fluttered folk and wild—
Your new-caught, sullen peoples,
Half-devil and half-child."

Rudyard Kipling 1899