Moreover, the very low prevalence of infection in Neanderthal populations suggests that infection was an unlikely cause, leaving nutritional deficiencies, especially in the form of periodic food shortages, as the most likely causative agents.
句中：especially in the form of periodic food shortages 和as the most likely causative agents 分别干什么成分，修饰什么？
leaving nutritional deficiencies, especially in the form of periodic food shortages, as the most likely causative agents.
这是目前分词短语作补充性状语。目前分词leaving的逻辑主语为前面整个主句的内容。这个分词短语有哪些用途像非限制性定语从句which leaves..., which 的先行词为主句内容。
leaving sth as sth. leaving在此为使役动词，意为使 A 成为 B, 使得营养不足成为最大概是什么原因。as介词短语为leaving的宾语补足语。especially in the form of periodic food shortages 为介词短语作nutritional deficiencies的非限制性定语。有人会觉得这是插入语，对nutritional deficiencies作补充讲解。
