In 20th century words, Locke believed that there was no abstract information carried by DNA ... just physical information. This is absolutely essential to any understanding of this term.
DNA concerns the size & shape of the slate but ... the slate itself is blank. One person may have a different or better or worse slate and thereby be affected (genetically guided) in later life. A tendency to do "X" and not "Y" might be effected in this manner. This is not prohibited by the concept tabula rasa. Such tendencies, contingent upon genetically inherited, physical brain structure differences (or even other physical characterisics) may serve to guide the behavior of those who "cast their fates to the wind". But for those to whom abandonment to subconscious whim is anathema, all directions in life come from experience.
It is easy to see how a beautiful woman (beautiful by current standards) would have her life "guided" by the solicitous attentions of male suitors. She might also opt for guiding her own life independently. Neither of these alternatives flies in the face of tabula rasa.
If however, you contend that an abstraction is codified on the DNA strand, you are at odds. For instance, let us propose that Newton had a genetic predisposition to do mathematics. This is impossible by the standard of tabula rasa (unless there was an area of his brain devoted to doing abstract tasks which was much larger or physically better 'connected' than other people which would serve to give him a tendency toward doing abstract thinking). But there is no way to encode the concept of mathematics itself.
There is a possibility that man has some fear of snake forms buried in his genetic heritage. This is dubious and would constitute a tabula rasa violation. I do not entirely discount the possibility that some small vestigial "instinct" remains in man, but it is of the nature of the tailbone ... on the way out ... not exceptional enough to overturn the rule.
That man should perform instinctual actions runs counter to his design as a free thinking, adaptable entity living very much spontaneously and utilizing experience as his guide. This is his way of doing the business of life ... his means of survival.
Codifying an Abstraction in DNAOne wonders at the unreasonable expectations of some concerning the information carrying capacity of the DNA strand. How much can be encoded here? Certainly a very great deal ... sufficient to subtend the design of a human body. But certainly less than that required to encode the entire obverse plenum of actions - emotions - thoughts which are not the object of the code. By this I mean that an action cannot be encoded without specifying all actions which are not to be undertaken (an infinite quantity ... or close to it).
To encode "homosexuality" it would be necessary to code much more than "stick it where the sun don't shine". It would be necessary to differentiate the no shine area from all other possibilities such as: gopher holes, watermelons, grapefruit, chickens ... you get the picture.
When encoding physical atributes, it is not necessary to give a description of what an arm or leg is not. The arm, leg or stomach is specified without context. No context is necessary since no choice is possible. Cells do what they are programmed to do. They don't make mistakes. They don't make comparisons. They don't make choices ... period.
On the other hand, a mental option needs to be differentiated from the background in order for it to be selected. This means a "successful choice" requires the encoding of ... "This - not that" ... "This - not that" ..."This - not that" ... with every other option possible.
Concerning the correlation among twins raised apart ...
It is simply too vast