Extrapolating the Future

According to an article in New Scientist on how humans are currently evolving (seen via Overcoming Bias):

If these trends continue for 10 generations, Stearns calculates, the average woman in 2409 will be 2 centimetres shorter and 1 kilogram heavier than she is today.

If we extrapolate that and assume the average adult female height today is 160 cm, the average woman of the year 34009 will have a height of 0 cm.

I think I've taken this a little too far …