Evo-Devo of Child Growth III: Premature Juvenility as an Evolutionary Trade-Off

Abstract

Juvenility was previously defined as a distinct clinical life history stage, characterized by adrenarche, decelerating growth and accelerating adiposity. This review presents the theory of evolutionary predictive adaptive strategies for premature juvenility in response to (mostly) energy supply, but also to other environmental cues. In the absence of longitudinal adrenal androgen levels, premature juvenility can be diagnosed by auxological criteria. Syndromes of short stature that are associated with premature juvenility include Prader-Willi syndrome, Silver-Russell syndrome and Noonan syndrome, and it is part of the pygmy adaptive shortness of stature. The review elucidates in evolutionary terms the association of premature juvenility with SGA and PCOS.

Middle Childhood: An Evolutionary-Developmental Synthesis

“…Consistent with this view, a recent study has documented significant genetic correlations between puberty timing, insulin levels, type 2 diabetes, and cardiovascular disease (Day et al 2015). Moreover, some of those factors are likely to be expressed in sexually differentiated ways, and the different patterns of health risk associated with early adrenarche and puberty in boys and girls may be usefully interpreted in light of different constraints on life history trade-offs in the two sexes (see Hochberg 2010). These predictions are consistent with the nonlinear and multilevel nature of developmental processes-one of the guiding principles of LCHD emphasized in this volume.…”

“…The transition to middle childhood seems to be a switch point for a number of growth and metabolic processes that have long-term impact on health, including the risk for obesity and type 2 diabetes (Hochberg 2008(Hochberg , 2010. These processes become apparent in middle childhood (e.g., anticipated onset of the adiposity rebound, rapid weight gain, onset of insulin resistance), but respond to the accumulated effects of early nutrition and other sources of stress, starting from prenatal life (e.g., intrauterine growth restriction; see Salsberry et al 2017).…”

“…As I have argued in detail elsewhere (Del Giudice 2014b, c), a life history framework is especially useful in teasing out the logic of potentially adaptive combinations of traits, highlighting critical factors in the environment, and bridging behavioral development with physical growth trajectories. As an example, consider the association between intrauterine growth restriction and early maturation in children (Hochberg 2008(Hochberg , 2010. This can be interpreted as a manifestation of physiological dysregulation due to prenatal adversity or as an adaptive programming effect on children's metabolic processes and life history trajectories.…”

Adrenarche: a cell biological perspective

“…He convincingly links DHEAS to increased brain development, extended life span, and decreased sexual dimorphism. These ideas indicate that the significance of adrenarche lies in the evolution of the life history of the human species (Hochberg 2010). It is beyond the scope of this review to consider the function of DHEA(S) in human biology, and those who want to learn more about these ideas are referred to these excellent reviews.…”

“…Even chimpanzees may significantly differ from humans in the biology of infancy, childhood, juvenility, and adolescence (Hochberg 2010). Other primates, such as the marmoset, also develop specialized inner zones of the adrenal cortex that secrete androgens, but the extent to which primates other than the great apes resemble humans is uncertain (Pattison et al 2009).…”