There are several things I had in mind when saying that. Firstly, acquired propensities are not hereditary. This is to say that if the father or mother has attained or has not attained dhyana/samadhi has no effect on the chromosomes their children will inherit. I take Aryans, or the Overmen (of Nietsche), to mean persons who have attained concrete levels of the mundane or supramundane path. These attainments have no effect on their chromosomes, nor are these attainments caused by their chromosomes. Do you agree?
I wonder if there is certain genetic programming that is favourable to samadhi? Some people are natural athletes -- I wonder if there are natural meditators?
Actually I think I was fortunate to be born with flexible limbs, which would a physiological trait. From since I can remember I've been able to sit comfortably in full lotus without straining my legs. I don't have to stretch my legs either. I just sit down in full lotus in front of the computer or on the meditation cushion and I'm fine. I've never really had to struggle much with sitting in lotus, which has made meditation easier for me. Quite fortunate (or perhaps it is a just karmic reward from past lives? )
But as to your original question I don't think meditation has an effect on your chromosomes, but then maybe it might affect which chromosomes you come to inherit in your future lives.
I think Buddha's teaching is meant for people at large, not just for renunciates, it is the same for different classes of people. In Dhammapada there is a sentence that Lust is a blemish of mankind. It is quite rare that a person is interested in Dharma, but if he takes interest in it it is similar, like gravity is similar whether you are renunciate or not.
Indeed the teachings are applicable, but some teachings will likely be seen as disagreeable by those without the strong will to renounce samsara.
I think it is easy to detect that Pali Scriptures have been edited in such a manner that all teachings given to laymen, laywomen and people outside the sangha have been eradicated or changed so that it seems that the Shakyamuni always and exclusively taught the monks, which certainly is not a historical truth.
Why would there be right livelihood in the Noble Eightfold Path if the teaching is aimed at renunciates exclusively? The interpretations of "livelihood" are strained, I think, that you find in Pali sources.
I think the monastic community was the party most likely to remember and then record their teachings. The commoners coming to the Buddha would have received great teachings, but the means to remember and transmit those teachings probably were scarce. Folk tales I'm sure existed about the Buddha, but those can only last so many generations.