That's just not true Alan. We can't test for the specific gene frequencies in 99 percent of the phenotypic characteristics that are rooted in the genome, even such common things as the ability to have five fingers. Yet, scientists can and have tested for the genetics of lung capacity in animals and found there is a very significant (more than 70 percent I believe the tests show) of a genetic component. They have also done this through twin studies. Then applied to humans, they have found how "plastic" human lung capacity is or is not. It's not very plastic -- it only has a circumscribed response to conditioning. I believe you are confusing apples and oranges. We can definitively know something is genetically grounded in part without knowing the exact mechanisms for it. That's true for most scientific theories, from gravity to evolution to Copernican theory. Testing at >birth wouldn't tell you much since your growth is to a large degree >genetically programmed. It would have to be after the last growth spurt. Well, then there would be no good way to test for genetic lung capacity because after birth you will improve your lung capacity by your activity (running to and from school, tending to the flock). It could be that a certain group of people turn out to be great runners because the walk and run a lot as children. Take a look at US history over the past 50 years. We have turned more and more away from our rural roots. Our children sit around, watch TV and get fat. That is why we have the highest child obesity rate in the world....we are lazy as a whole. That was not true 50 years ago. Alan -- Jon Entine RuffRun 6178 Grey Rock Rd. Agoura Hills, CA 91301 (818) 991-9803 [FAX] 991-9804 http://www.jonentine.com