Department of Anthropology, University of Alabama, Tuscaloosa, Alabama 35487, USA.
Am J Hum Biol. 2010 Sep-Oct;22(5):657-66. doi: 10.1002/ajhb.21062.
This study examines sex differences in vulnerability among children experiencing rapid culture change that may reflect distinct microecologies driven by differential parental investment and/or sex-specific life history strategies. Apparent female growth canalization may be a life history strategy favoring growth over maintenance but also may reflect sex-differentiated selection for resilience based on unequal treatment during early life.
Stature, weight, and serum measures of C-reactive protein (CRP, an inflammation marker) and Epstein-Barr Virus antibodies (EBV, a humoral immune response marker) were collected longitudinally among children/adolescents ages 5-20 years (N = 65), 5-9 years after sustained contact in a fringe highland hunter-horticulturalist group from the Schrader Range in Papua New Guinea exhibiting male preference and sex-biased survival. It was hypothesized that girls would exhibit canalization, with better nutritional status than boys; lower maintenance investment would yield lower female immune activation; and because of differential survivorship, females would appear increasingly canalized as early conditions for girls worsened relative to boys.
Girls had greater arm circumference z-scores than boys, less frequent stunting, and lower CRP despite high pathogen load. Average nutritional status for girls improved over time as the sex ratio became increasingly male biased and the condition of female infants reportedly worsened.
Both canalization and survivorship effects were found. Although a life history perspective on female canalization can help explain developmental outcomes in populations undergoing rapid culture change amid adversity, possible sex differences in the strength of survivorship effects that select for resiliency should not be ignored.
本研究考察了在经历快速文化变迁的儿童中，性别差异导致的脆弱性，这种变迁可能反映了由父母投资差异和/或性别特定的生活史策略驱动的不同微观生态。明显的女性生殖道分化可能是一种生活史策略，有利于生长而不是维持，但也可能反映了基于早期生活中不平等待遇的性别分化的弹性选择。
在巴布亚新几内亚 Schrader 山脉的一个边缘高地狩猎采集群体中，持续接触 5-9 年后，对 5-20 岁（N=65）的儿童/青少年进行了纵向身高、体重和 C 反应蛋白（CRP，炎症标志物）和 Epstein-Barr 病毒抗体（EBV，体液免疫反应标志物）血清测量。假设女孩会表现出分化，营养状况比男孩好；较低的维持投资会导致女性免疫激活降低；由于生存差异，随着女孩的早期条件相对于男孩恶化，女性会表现出越来越明显的分化。
女孩的臂围 Z 分数大于男孩，生长迟缓的频率较低，尽管病原体负荷较高，但 CRP 较低。随着性别比例变得越来越偏向男性，女孩的平均营养状况随着时间的推移而改善，据报道，女婴的状况恶化。
发现了分化和生存效应。虽然从生活史的角度来看，女性的分化可以帮助解释在逆境中经历快速文化变迁的人群的发育结果，但不应忽视可能存在的性别差异，即生存效应的强度会选择弹性。
