Hormones and Human and Nonhuman Primate Growth

Area of Science:

• Endocrinology
• Evolutionary Biology
• Primatology

Background:

• Hormonal regulation is crucial for primate growth and development.
• The growth hormone (GH)-insulin-like growth factor (IGF) axis and adrenal androgens are key endocrine systems.
• Understanding primate growth patterns can shed light on human evolutionary development.

Purpose of the Study:

• To review hormonal regulation of nonhuman primate growth.
• To focus on the GH-IGF axis and adrenal androgens.
• To compare primate growth patterns with human development.

Main Methods:

• Literature review of existing studies on primate growth and endocrinology.
• Analysis of hormonal data, including GH, IGFs, and adrenal androgens (DHEA, DHEAS).
• Comparative analysis of adrenarche timing across primate species.

Main Results:

• GH-IGF axis hormones correlate with growth (linear, weight) during development but not adult size.
• Adrenal androgens (DHEA, DHEAS) patterns may indicate unique human/ape developmental stages.
• Adrenarche is delayed in humans, chimpanzees, and possibly gorillas, but early in macaques.

Conclusions:

• Primate growth is significantly influenced by hormonal regulation.
• The timing of adrenarche suggests that human childhood development builds on ancestral substrates.
• Hormonal insights are vital for understanding the evolution of the human growth trajectory.