Only in the most shallow possible reading. Here's the context:
> We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.
Equal, in other words, not in innate capacities - a patently foolish notion, to anyone who's known enough people to count on two hands - but rather in worth in the eyes of God, and thus, deriving from that ultimate source of morality, in the eyes of men as well - and further, that deriving from this radical equality, all men possess in the same degree those rights which enable the construction of a worthy and satisfactory life, each man by his own lights.
Yes, Jefferson was a slaveowner, and yes, for all the protestations of 'man' meaning the species, he did somewhat forget about women. The Declaration is in every sense aspirational, and we need not discard its astonishing and rather lovely idealism because its author had feet of clay.
Nor need we discard it because of genetic determination of intelligence, to whatever extent that occurs. To do so requires that we take as axiomatic, or self-evident, that intelligence is the only meaningful measure of human worth. I don't think that accurately describes the world in which we live. I don't think that such a world is one that any of us wants to see built, and if we find ourselves having done so nonetheless, I confide that history will judge us most harshly for it - and deservedly so, as I can imagine few regimes more chilly to optimism and hope, more destructive of ambition and achievement, than that in which a particular combination of abstract reasoning and symbol-manipulation skills holds perfect hegemony over the conception of human value, and all else is treated as fungible and ultimately meaningless.
When Jefferson was alive the consensus was that black people did not have enough intelligence to coexist with white people unless they were segregated. Equality of rights at the time only applied to white people (and even then to British whites) and only was only extended to blacks in practice due to the assumption that they have the same intelligence as whites.
While I think that all people should have equal rights, in practice only people with high enough intelligence will be born, let alone have equal rights, once embryo selection and genetic engineering are the norm, unless we find some sort of black magic that can boost intelligence of adult humans to the same IQ GMO people have.
Have you seen the effect size, and the assumptions that went into it? Gattaca is far enough out that maybe it's a waste of time to start worrying about it just yet.
Geographic effects on athleticism: most people get out of breath speed-walking in Tibet because the air is thinner. It's hard to run in Antarctica because of all the clothes you have to wear to stay alive in extreme cold. Most people can only do a few push-ups before drowning when placed on the floor of the continental shelf off Cape Cod.