KT Leitl
• Genes in hair color aren’t fully established.
• Theory – At least two gene pairs control human hair color
• Two pigments for hair color: Eumelanin and Pheomelanin
• Eumelanin – The two subtypes determine the darkness
• Black – High counts lead to blacker hair, lower counts result in gray hair
• Brown
Pheomelanin
• Pheomelanin - is generally
makes red
Phenotypes
• Brown/Blonde
• Brown – Dominant allele
• Blonde – Recessive allele
• Non-red/Red
• Non-red – Dominant (suppresses
pheomelanin
• Red - Reccessive
• Higher levels of (brown)
eumelanin
• Lower levels of
pheomelanin
• Medium to thick
hairstrands
• Most common
• Ranging from soft black,
blue-black, and jet black
• Lots of eumelanin
• Less dense color
• Platinum blonde, dark
blonde, strawberry
blonde (most rare and
contains the most
pheomelanin)
• Only small amounts of
pheomelanin and
eumelanin (more creates
ash blonde)
• Most blondes get darker
with age
• Ranges from light to
dark red-brown
• Eumelanin (brown)
• Pheomelanin (red)
• Red-ish shade of brown
• Darker than auburn
• Least common
• Light strawberry, titan vivid
orange, copper, “true red”
(least common)
• Caused by Mc1r
(recessive)
• 67% pheomelanin
• Lowest levels of eumelanin
• Most common in Scotland
(13% are, 40% carry the
recessive gene)
• No actual pigment
• Clear hair
• Lack of pigment and
melanin
• Color based on light
reflection
• Generally in people of
age
• As early as ten
Men
• Generally black of dark hair
Women
• Red and blond hair
• En.wikipedia.org/wiki/Human_hair_color
• Google images