We love the notion that farming is an easy, weakening way of living. One wonders how much time farming people who sprout such nonsense have engaged in.
That isn't what the author said. The author said there was a temporary change in skeleton because the diet was lower in protein and farming was wearisome, meaning harder.
"When people make the transition from hunter-gathering to settled agriculture, their skeletons change - they temporarily grow smaller and less healthy as the human body adapts to a diet poorer in protein and a more wearisome lifestyle. Likewise, newly domesticated animals get scrawnier."