Mammals (class of vertebrates)

Monotremes, Marsupials, Placentals

Mammals (characteristics)

Produce milk for their young, socketed teeth, diaphragm for breathing, hair (why?) —> warmth, intimidation, exual dimorphism, vestigial in humans

Anatomy —> Follicle

Organ which grows (1 cm/month) and contains most DNA (shaft has only mitochondrial DNA)

Anatomy —> Cuticle

Outside covering of hair, can be coronal, spinous, and imbricate

Anatomy —> Cortex

Contains Melanin (pigment granules which give hair color)

Anatomy —> Medulla

Central canal running through shaft, human medulla is continuous, interrupted, fragmented, absent

Medullary Index

Diameter of medulla relative to diameter of shaft. Humans less than or equal to 1/3, while other mammals are greater than or equal too ½

Comparison and identification of hair. NONHUMAN OR HUMAN?

Follicle, cuticle (scale) pattern - Imbricate, Medullary Pattern - Amorphous, Medullary Index <.33, hair width - 80um

Comparison and identification of hair —> Can determine:

if Forcibly removed, body area of origin, race

Comparison and identification of hair —> can’t determine

ex, age other than infant