Chapter 15 Human Variation and Adaptation

1
Chapter 15Human Variation and Adaptation

• Key Terms

2

• monogenismTheory that all humans were descended
  from a original pair of humans.
• polygenismTheory that all humans were descended
  from a number of pairs of humans.

3

• plasticityThe ability of organisms to make
  alterations in order to respond to differing
  conditions.
• dolichacephalicHaving a long, narrow head in
  which the width measures less than 75 of the
  length.

4

• brachycephalicHaving a broad head in which the
  width measures more than 80 of the length.
• biological determinismConcept that various
  aspects of behavior are governed by biological
  factors inaccurate association of various
  behavioral attributes with certain biological
  traits such as skin color.

5

• eugenicsPhilosophy of race improvement through
  the forced sterilization of members of some
  groups and encouraged reproduction among others.
• polytypicReferring to species composed of
  populations that differ with regard to the
  expression of one or more traits.

6

• stressIn a physiological context, any factor
  that acts to disrupt homeostasis more
  precisely, the bodys repose to any factor that
  threatens its ability to maintain homeostasis.
• homeostasisA condition of balance, or stability,
  within a biological system, maintained by the
  interaction of physiological mechanisms that
  compensate for changes.

7

• acclimatizationPhysiological response to changes
  in the environment that occurs during an
  individuals lifetime.
• neural tubeIn early embryonic development, the
  anatomical structure that develops to form the
  brain and spinal cord.

8

• spina bifidaA condition in which the arch of one
  or several vertebrae fails to fuse and form a a
  protective barrier around the spinal cord.
• vasodilationRefers to widening (dilation) of the
  capillaries near the skin's surface permitting
  "hot" blood from the body's core to dissipate
  heat to the surrounding air.

9

• vasoconstrictionNarrowing of blood vessels to
  reduce blood flow from the skin.
• vectorsAgents that serve to transmit diseases
  from one carrier to another.

10

• endemicContinuously present in a population.
• pathogensSubstances or microorganisms, such as
  bacteria, fungi, or viruses, that cause disease.