Evolutionary and biomedical consequences of internal melanins

Area of Science:

• Zoology
• Physiology
• Evolutionary Biology

Background:

• The adaptive role of integumentary melanin is established.
• The function of melanin in internal organs remains largely unknown.

Purpose of the Study:

• To review the literature on the function of internal melanin.
• To explore the relationship between internal melanin and external coloration.

Main Methods:

• Literature review of studies on internal melanin.
• Analysis of correlations between external and internal melanin deposition.

Main Results:

• Internal melanin provides protection against parasites, pollutants, low temperature, oxidative stress, hypoxemia, and UV light.
• It is implicated in organ development and function.
• A positive correlation exists between external body surface melanin and internal melanin levels.

Conclusions:

• Internal melanin has significant physiological roles, potentially more pronounced in darker individuals.
• External coloration and internal melanin may co-evolve.
• Indirect selection likely plays a crucial role in the evolution of internal melanin.