With enough experimentation to test observational results, a science could be thought of as 'maturing' into prediction.
Some sciences, however, remain absent from meaningful experiment due to practical reasons (Geologists cannot 'experiment' with plate tectonics, at least before the days of global models).
Of these 'observational' sciences, which has progressed farthest?
There can be no doubt that the the most "mature" observational science is astronomy. Whatever is the exact meaning of "mature". First, it is the oldest science among all exact sciences. There was no physics to talk about, (not speaking of chemistry biology, geology) when astronomy was already quite mature.
Second, astronomy makes predictions. Very precise predictions, and for very long time. The most exact measurements available also belong to astronomy. Astronomy can predict events that will happen thousand years from now with accuracy to a fraction of a second. Time measurements in astronomy are the most precise measurements (in terms of the number of significant digits) in any science.
Many different kinship structures have arisen in small human societies from prehistoric times in order to avoid a variety of genetic disorders. Maybe I'm drawing a long bow here, but I'd say observations of the result of close (and distant) genetic relationships led to deliberate attempts to improve plants and animals through selective breeding, and via Mendel and others, to the modern science of genetics.
