You make observations, write theories to fit them, try experiments to disprove the theories and, if you can't, you've got something.
Science grows like a weed every year.
Natural DNA is a tractless coil, like an unwound and tangled audiotape on the floor of the car in the dark.
Science has not been successful by making up explanations of things that fit with the current social fabric.
My grandfather milked several cows twice a day and supplied the neighbours with dairy products. He liked to go visiting around the county on Saturdays, and he also enjoyed the neighbours when they came by once a week with their empty milk jars. He walked them out to their cars and hung over the driver's side window until they drove off.
If reincarnation is a useful biological idea it is certain that somewhere in the universe it will happen.