Biological Anthropology Exam #2 Study Guide

What is the Hardy-Weinberg Equilibrium Equation used for?

measuring microevolution in real time (a small scale evolutionary change)

Who is the Hardy-Weinberg Equilibrium Equation named after?

G.H. Hardy and Dr. Wilhelm Weinberg

What are the 6 conditions that the H-W law sets for evolution NOT to occur

no natural selection

random mating - in reality, mating is preferential

equal fertility

no gene flow between populations/demes

no genetic drift

no mutations

What is gene flow?

the exchange of genes/alleles between two or more populations/demes

What is a deme?

a localized grouping of individuals that share a common area and mate most often within that cluster

What is a gene pool?

it is all the genetic information within the overall breeding population

What is genetic drift?

the random change in allele frequency from generation to the next

What is the founder effect?

a type of genetic drift caused by the formation of a new isolated small population

Define mutations

a change in the nucleotide sequence in the DNA (the ultimate source of new variation)

What does Hardy-Weinberg NOT meaure?

it does not measure macroevolution

What is macroevolution?

large-scale evolutionary changes (that can be viewed in the fossil records)

Define species.

a group of related organisms that can interbreed and produce fertile offspring

What is speciation?

the process by which species give rise to new species

What is directional selection?

selection for one allele over the other alleles (causing the allele frequencies to shift in one direction)

What is disruptive selection?

selection of the alleles for both extremes of the phenotypic distribution

Define ecological niche.

the specific habitat or ecological role filled by an organism in the broader environment (the way in which an organism “makes a living”)

What is allopatric speciation?

the process by which new species emerge due to the physical, geographic isolation of populations, preventing gene flow

What are the 7 steps by which one species can become two entirely different ones?

1. geographic isolation occurs (e.g. river)

2. now one species is split into two - demes

3. since they are split, gene flow is blocked off - allopatric speciation

4. each side has different ways of gathering food - ecological niche (e.g. trees vs. bushes)

5. mutations occur on both sides

6. mutations that better help survive and reproduce get chosen through natural selection

7. this results in the overall fitness of the species being able to survive and reproduce

Define taxonomy.

the classification of living things into a system that reflects the degree of relatedness

Define phylogeny.

the evolutionary history of a species

Define homology.

a similarity between species due to inheritance from a common ancestor

What are some examples of primitive characteristics?

segmented spines

humerus

five digits

What are clades?

groups of organisms that evolved from a common ancestor

True or false: the more homologies, the smaller the clade

true

What is a derived characteristic?

a trait that is unique or nearly unique to a given species

What are some derived traits in humans?

full bipedality

number of sweat glands

large u-shaped hyoid bone

human uvula

What does arboreal adaptation mean?

being very good at living in trees

What is Notharctus?

one of the first primates

What is Carpsolestes Simpsoni?

one of the first monkey-like creatures

What are the 12 generalized characteristics of the order, primates?

1. opposable thumbs, big toe

2. nails instead of claws

3. enhanced sense of touch

4. flexible, generalized body structure

5. enhanced sense of vision

6. reduced sense of smell

7. reduced number of teeth

8. large brain relative to body size

9. reduced number of offspring

10. prolonged infant dependency

11. greater reliance of learned behavior and problem solving

12. Highly social

What does binocular vision mean?

the eyes are forward and stereoscopic

What does stereoscopic mean?

to have a 3-D depth perception

What does rhinarium mean?

wet nose

What are the two types of primates and their meaning?

1. strepsirrhine (strep-sir-hine), meaning “wet-nosed”

2. haplorrhine (hap-or-ine), meaning “dry-nosed”

What does the strepsirrhine clade consist of?

lemurs, lorises and galagoes

What does the haplorrhine clade consist of?

tarsiers, monkeys and apes

What are the characteristics of strepsirrhines?

1. larger snout

2. eyes more laterally placed

3. grooming claw and dental combs

4. relatively fixed facial features