Compensatory growth (CG) may be an adaptive mechanism that helps to restore an organisms' growth trajectory and adult size from deviations caused by early life resource limitation. Yet, few studies have investigated the genetic basis of CG potential and existence of genetically based population differentiation in CG potential. We studied population differentiation, genetic basis, and costs of CG potential in nine-spined sticklebacks (Pungitius pungitius) differing in their normal growth patterns. As selection favors large body size in pond and small body size in marine populations, we expected CG to occur in the pond but not in the marine population. By manipulating feeding conditions (viz. high, low and recovery feeding treatments), we found clear evidence for CG in the pond but not in the marine population, as well as evidence for catch-up growth (i.e., size compensation without growth acceleration) in both populations. In the marine population, overcompensation occurred individuals from the recovery treatment grew eventually larger than those from the high feeding treatment. In both populations, the recovery feeding treatment reduced maturation probability. The recovery feeding treatment also reduced survival probability in the marine but not in the pond population. Analysis of interpopulation hybrids further suggested that both genetic and maternal effects contributed to the population differences in CG. Hence, apart from demonstrating intrinsic costs for recovery growth, both genetic and maternal effects were identified to be important modulators of CG responses. The results provide an evidence for adaptive differentiation in recovery growth potential.
Postpartum depression is the most prevalent emotional problem during a women's lifespan. Untreated postpartum depression may lead to several consequences such as child, infant, fetal, and maternal effects. The main purpose of this article is to briefly describe different theoretical perspectives of postpartum depression. A literature search was conducted in Psych Info, PubMed, and Science Direct between 1950 and 2015. Additional articles and book chapters were referenced from these sources. Different theories were suggested for developing postpartum depression. Three theories, namely, biological, psychosocial, and evolutionary were discussed. One theory or combinations of psychosocial, biological, and evolutionary theories were considered for postpartum depression. The most important factor that makes clinicians' choice of intervention is their theoretical perspectives. Healthcare providers and physicians should help women to make informed choices regarding their treatment based on related theories.