UARK Biological Anthropology Exam 2
Questions with Complete Answers
Melanin - Answer-A pigment that causes the variation that we observe in skin tones:
can absorb UV radiation (natural sun block)
Global Geographic Pattern of Human Skin Color - Answer-Basically a balancing act
between the evolutionary demands of photo-protection and the need to create vitamin D
in the skin, based off intensity of UV light, two types:
1. Latitudinal Gradients (darkest in tropics, lightens as you go towards poles)
2. Altitude Gradients (darkest when higher)
Vitamin D - Answer-Naturally manufactured when skin comes in contact with the sun,
can also get it through food
The darker your skin, the less of this you have - Answer-Vitamin D
A negative effect of Vitamin D - Answer-Rickets (brittle bones)
Majority of African Americans report being deficient in this - Answer-Vitamin D
Skin Cancer - Answer-Above all, a somatic mutation: caused by UV Radiation and most
cases for European-Americans
Folate - Answer-Helps fetuses develop (mitosis): Destroyed by UV Radiation: Those
with Darker Skin have less folate destruction
Lactose - Answer-Milk sugar
Lactase - Answer-Enzyme in our body that breaks down lactose
Lactase Persistence - Answer-Persistence of the lactase enzyme into adulthood (the
ability to digest lactose as an adult)
How does this human skin color geographical pattern reflect natural selection? -
Answer-It reflects natural selection because skin pigmentation of humans evolved so as
to regulate the amount of ultraviolet radiation penetrating the skin, therefore controlling
the biochemical effects.
What is the geographical pattern of lactase persistence? - Answer-Southern European
populations, along with sub- Saharan African and Southeast Asian populations have low
levels of lactase persistence. Northern European populations have great amounts of
lactase persistence.
, What is the historical difference between populations with high levels of lactase
persistence and those with low levels of lactase persistence? - Answer-Populations
(mainly in Europe) which were surrounded by the rise of dairy farming have higher
levels of lactase persistence when compared to populations that did not experience the
growth of dairy farming. This goes for populations that consumer more dairy in general,
as well.
Malaria - Answer-Infection of red blood cells- spread primarily by mosquitos
Why is the sickle-cell hemoglobin more common in certain areas of the world? -
Answer-Because in some places (like in Africa), people who have sickle-cell
hemoglobin have an advantage when facing malaria.
What is a Balanced Polymorphism? - Answer-When the heterozygotes have a higher
fitness than both homozygotes: this rate is fixed
What is the Heterozygous Advantage? - Answer-You don't get sickle cell anemia or
malaria as often
The stable frequencies of alleles
Two rules that describe human body shape variation - Answer-1. Allen's Rule
2. Bergmann's Rule
Allen's Rule - Answer-Endotherms (warm-blooded animals/humans) from cold regions
have shorter limbs than populations from warmer regions (this means appendages)
Bergmann's Rule - Answer-Endotherms in cold regions tend to be larger in body size
(body mass) than those from warmer regions
How would you describe the body shape of tropical adapted populations? - Answer-
Less massive and long arms/legs
How would you describe the body shape of polar adapted populations? - Answer-Larger
body mass, short/small appendages (short but massive)
How does the ratio of surface area to volume play into human body shape variation? -
Answer-Volume stays the same, but areas can differ (think block example)
Highest surface area to volume ratio: the more efficiently you release heat (therefore,
shorter and stouter means more efficient heat management)
Genetic Drift - Answer-Random changes in allele frequencies (prevalent in smaller
population sizes)
Old Order Amish Genetic Drift - Answer-Founder's Effect (endogamy): would only mate
with people in their group
Questions with Complete Answers
Melanin - Answer-A pigment that causes the variation that we observe in skin tones:
can absorb UV radiation (natural sun block)
Global Geographic Pattern of Human Skin Color - Answer-Basically a balancing act
between the evolutionary demands of photo-protection and the need to create vitamin D
in the skin, based off intensity of UV light, two types:
1. Latitudinal Gradients (darkest in tropics, lightens as you go towards poles)
2. Altitude Gradients (darkest when higher)
Vitamin D - Answer-Naturally manufactured when skin comes in contact with the sun,
can also get it through food
The darker your skin, the less of this you have - Answer-Vitamin D
A negative effect of Vitamin D - Answer-Rickets (brittle bones)
Majority of African Americans report being deficient in this - Answer-Vitamin D
Skin Cancer - Answer-Above all, a somatic mutation: caused by UV Radiation and most
cases for European-Americans
Folate - Answer-Helps fetuses develop (mitosis): Destroyed by UV Radiation: Those
with Darker Skin have less folate destruction
Lactose - Answer-Milk sugar
Lactase - Answer-Enzyme in our body that breaks down lactose
Lactase Persistence - Answer-Persistence of the lactase enzyme into adulthood (the
ability to digest lactose as an adult)
How does this human skin color geographical pattern reflect natural selection? -
Answer-It reflects natural selection because skin pigmentation of humans evolved so as
to regulate the amount of ultraviolet radiation penetrating the skin, therefore controlling
the biochemical effects.
What is the geographical pattern of lactase persistence? - Answer-Southern European
populations, along with sub- Saharan African and Southeast Asian populations have low
levels of lactase persistence. Northern European populations have great amounts of
lactase persistence.
, What is the historical difference between populations with high levels of lactase
persistence and those with low levels of lactase persistence? - Answer-Populations
(mainly in Europe) which were surrounded by the rise of dairy farming have higher
levels of lactase persistence when compared to populations that did not experience the
growth of dairy farming. This goes for populations that consumer more dairy in general,
as well.
Malaria - Answer-Infection of red blood cells- spread primarily by mosquitos
Why is the sickle-cell hemoglobin more common in certain areas of the world? -
Answer-Because in some places (like in Africa), people who have sickle-cell
hemoglobin have an advantage when facing malaria.
What is a Balanced Polymorphism? - Answer-When the heterozygotes have a higher
fitness than both homozygotes: this rate is fixed
What is the Heterozygous Advantage? - Answer-You don't get sickle cell anemia or
malaria as often
The stable frequencies of alleles
Two rules that describe human body shape variation - Answer-1. Allen's Rule
2. Bergmann's Rule
Allen's Rule - Answer-Endotherms (warm-blooded animals/humans) from cold regions
have shorter limbs than populations from warmer regions (this means appendages)
Bergmann's Rule - Answer-Endotherms in cold regions tend to be larger in body size
(body mass) than those from warmer regions
How would you describe the body shape of tropical adapted populations? - Answer-
Less massive and long arms/legs
How would you describe the body shape of polar adapted populations? - Answer-Larger
body mass, short/small appendages (short but massive)
How does the ratio of surface area to volume play into human body shape variation? -
Answer-Volume stays the same, but areas can differ (think block example)
Highest surface area to volume ratio: the more efficiently you release heat (therefore,
shorter and stouter means more efficient heat management)
Genetic Drift - Answer-Random changes in allele frequencies (prevalent in smaller
population sizes)
Old Order Amish Genetic Drift - Answer-Founder's Effect (endogamy): would only mate
with people in their group
