Predictive adaptive responses in perspective

In a recent opinion article, Wells accepts our fundamental claim that early metabolic plasticity in humans can contribute to later disease if there is a disparity (‘mismatch’) between nutritional experience at different phases of life, but he revives a debate and about the nature and function of the cue directing such plasticity. As in that earlier exchange, Wells argues that (i) the interests of mother and offspring are distinct, (ii) the only traits of interest are nutritional and metabolic and (iii) modern humans are in some way ‘special’ because of their extended lifespan and reproductive strategy. He argues that in humans prediction has been abandoned for a backward-looking strategy that operates solely for maternal benefit. We have explained elsewhere why we do not believe this to be the case. We suggest that a broader approach is needed because (i) evolution maximizes inclusive fitness, requiring optimization of the outcomes of the set of maternofetal dyads produced across the mother's reproductive life, (ii) plasticity cued by early-life information operates through trade-offs among the whole suite of life-history traits, and it is misleading to concentrate on a single trait and (iii) as in other species, humans use the mechanisms of developmental plasticity cued by information from the past and the present to prepare for the future