dhfr triple mutant He changes over time (50R/51I/108N).

The figure shows variation in He surrounding dhfr for parasites carrying a 50R/51I/108N mutants during the 1980s (n = 14) and 1990s (n = 92). Note that He around the triple mutants seems similar between the two decades. The two flat, dashed lines represent two different estimates of neutral He in Brazil.