Skin Coloration

Melanin and melanocyte image Skin is a protective layer that guards humans from external dangers. Skin is composed of various components which combine to make it the largest organ of the human body. Skin protects the body in many ways and is vital to many bodily processes. Just to name a few, skin provides protection from:

Harmful bacteria or viruses
Sun
Other organ damage
Blood loss
Water loss

Skin also provides additional services in the body such as:

Insulation
Temperature regulation
Sensation
Production of Vitamin D

One particular pigment in the skin known as melanin is mostly responsible for skin color. Melanin is produced in cells called melanocytes and is the main factor in darker skin colors. A person with more melanin has a darker skin color, whereas a person with less melanin has a lighter skin color. Skin color is also linked to geography. Indigenous populations living closest to the equator generally have darker skin. Why is this? Scientists think it evolved to protect the body from excess UV radiation. Melanin protects skin from both UV light and skin cancers. Recent research in Forensics has centered on Forensic phenotyping. Just as DNA is analyzed for gender and sequencing, it can also be used to determine skin, hair and eye color in some instances. This is an area of research that has garnered much interest because it could revolutionize the search for offenders. A sample of the offender's blood left at the crime scene might one day reliably yield this important information and could significantly impact the investigation for a suspect!

While skin's main function is to protect a living body, it can also give important clues even after a person has died. After death, skin undergoes many changes due to the decomposition process. Not only can skin colorations help investigators estimate the time of death by observing the skin color patterns, they can also determine if a body has been moved after death.

The presentation below will further explain post-mortem skin coloration patterns.

[CC BY 4.0] UNLESS OTHERWISE NOTED | IMAGES: LICENSED AND USED ACCORDING TO TERMS OF SUBSCRIPTION