Tag oughts

Natural oughts? Is there such a thing as natural?

I was wondering today, as I lay there with one of my twins in my arms, as to whether oughts can be derived from a natural pre-programmed’ behaviour. For example, if an evolved characteristic, such as aggressiveness in males (I am generalising here, of course) or to want to eat meat, or, if it could be proven, that it were ‘natural’ to be heterosexual was inherent in a human, are we then obliged in some way to act in accordance with that ‘natural’ inclination?