The relationship between heredity and IQ in human beings is well established. But that does not mean that if you have a group difference, an ethnic difference, that difference must also be genetic.
I know lots of women who have slim legs but refuse to wear skirts because of unsightly varicose or spider veins. Though heredity plays a role, your genes don't have to doom you to a life of long pants.
Here he tells us that the new birth is first of all 'not of blood'. You don't get it through the blood stream, through heredity. Your parents can give you much, but they cannot give you this.
Both of these branches of evolutionary science, are, in my opinion, in the closest causal connection; this arises from the reciprocal action of the laws of heredity and adaptation.
The man of the future may, and even must, do things impossible in the past and acquire new motor variations not given by heredity.
Of course, I also attribute some of my hearing loss to being in the infantry in World War II. It's probably a combination of heredity and noise exposure.
Heredity provides for the modification of its own machinery.
For me, ancestry is just one thing that connects us to people, and feeling connected to other people is generally a good thing, as long as one kind of connection does not have primacy over all the others. Heredity, race and nationhood are not the best criteria by which to judge our fellow humans.
We do not know, in most cases, how far social failure and success are due to heredity, and how far to environment. But environment is the easier of the two to improve.