Human Evolution Midterm (copy) (copy)

Evolution

A change in the allele frequencies in a population over time.

Natural Selection

An evolutionary process that occurs when certain phenotypes confer an advantage or disadvantage in survival and/or reproductive success. This is one of the forces of evolution.

Non-Random

Natural Selection: Random or Non-Random?

Mutation

A change in the nucleotide sequence of the genetic code. This is one of the forces of evolution.

Random

Mutation: Random or Non-Random?

Genetic drift

Random changes in allele frequencies within a population from one generation to the next. This is one of the forces of evolution.

Random

Genetic Drift: Random or Non-Random?

Gene Flow

The movement of alleles from one population to another. This is one of the forces of evolution.

Random

Gene Flow: Random or Non-Random?

Sexual Selection

An aspect of natural selection in which the selective pressure specifically affects reproductive success (the ability to successfully breed and raise offspring).

Non-Random

Sexual Selection: Random or Non-Random?

Artificial Selection (i.e., domestication)

Human-directed assortative mating among domestic animals, such as pets and livestock, designed to increase the chances of offspring having certain desirable traits.

Non-Random

Artificial Selection (i.e., domestication): Random or Non-Random?

Variation in a trait, inheritance of the trait, variants of the trait cause differential reproductive success

Three necessary & sufficient conditions of selection

Species change over time, evolution is gradual, the primary mechanism of evolution is natural selection, evolution results in speciation, all organisms are related by descent from a common ancestor

Darwin’s Five Theories of Evolution

The average

Stabilizing selection: Selected for

Both extremes

Stabilizing selection: Selected against

Both extremes

Disruptive selection: Selected for

The average

Disruptive selection: Selected against

One extreme

Directional selection: Selected for

One extreme

Directional selection: Selected against

Directional selection

Fill in the blank

Disruptive selection

Fill in the blank

Stabilizing selection

Fill in the blank

Grade

Reptiles represent a(n) ___ because this grouping does not include the ancestor and all of its descendants.

Clade

Mammals represent a(n) ___ because this grouping includes the last common ancestor and all of its descendants.

Homology

Whales, bats, and humans all possess mammary glands due to ___, a trait shared due to common ancestry.

Convergence

Humans, kangaroos, and penguins are all bipedal due to ___, a trait shared due to common function.

Unique derived

The blow hole represents a(n) ___ trait in whales, which is not useful for reconstructing evolutionary relationships.

Ancestral

Egg laying represents a(n) ___ trait in vertebrates.

Shared, derived

Mammary glands represent a(n) ___ trait within vertebrates, allowing us to separate out grade.

Bergmann’s Rule

For a broadly distributed monophyletic group, species and populations of smaller size tend to be found in environments with warmer climates and those of larger size tend to be found in ones that are colder.

Allen’s Rule

Due to thermal adaptation, homeothermic animals have body volume-to-surface ratios that vary inversely with the average temperature of their environment. In cold climates, the anticipated ratio is high, and it is low in warm climates.

Bergmann’s Rule

Ungulates from cooler environments (moose) have more body weight and less surface area than ungulates from warmer environments (gazelle). What rule is this an example of?

Allen’s Rule

Rabbits in the Arctic have shorter limbs and ears than rabbits in the desert. What rule is this an example of?

Adaptation

Alteration in population-level gene frequencies related to environmentally induced selective pressures; leads to a greater level of fitness for a population related to a specific environment.

No mutation, no gene flow, infinite population size, random mating, no selection

Five Assumptions of Hardy-Weinberg Equilibrium

Strepsirrhines

1

Haplorrhines

2

Anthropoids

3

Platyrrhines

4

Catarrhines

5

Outgroup

6

Lemurs

7

Lorises and Galagos

8

Tarsiers

9

New World Monkeys

10

Old World Monkeys

11

Apes

12

Bilophodont molars

13

Loss of tail, Orthogrady

14

Tympanic tube, 2:1:2:3 dental formula

15

Fused mandible, Full orbital convergence

16

Post-orbital wall

17

Toothcomb

18

Post-orbital bar, 3 premolars

19

Orbital bar and wall

1

Orbital bar

2

Crania

3

Humerus

4

Scapula

5

Post crania

6

Innominate

7

Femur

8

Foramen magnum

9

Auditory bulla

10

Tube

11

Non-bilophodont molars

12

Bilophodont molars

13

Terrestrial (knuckle-walking), some arboreal

Chimpanzee (pan troglodytes) locomotion

Africa (outside Congo river)

Chimpanzee (pan troglodytes) geographic location

Fruit

Chimpanzee (pan troglodytes) diet

Polygyandrous

Chimpanzee (pan troglodytes) mating system

Moderate

Chimpanzee (pan troglodytes) sexual dimorphism (yes, no, moderate)

Africa (inside Congo river)

Bonobo (Pan paniscus) geographic location

Terrestrial (knuckle-walking), some arboreal

Bonobo (Pan paniscus) locomotion

Leaves, fruit, insects

Bonobo (Pan paniscus) diet

Polygyandrous

Bonobo (Pan paniscus) mating system

Moderate

Bonobo (Pan paniscus) sexual dimorphism (yes, no, moderate)

Africa (outside Congo river)

Gorilla (Gorilla gorilla) geographic location

Terrestrial (knuckle-walking), some arboreal

Gorilla (Gorilla gorilla) locomotion

Foliage, fruit

Gorilla (Gorilla gorilla) diet

Polygynous

Gorilla (Gorilla gorilla) mating system

Yes

Gorilla (Gorilla gorilla) sexual dimorphism (yes, no, moderate)

Female defense

Gorilla (Gorilla gorilla) method of mating competition

Southeast Asia

Orangutan (Pongo) geographic location

Arboreal

Orangutan (Pongo) locomotion

Fruit, leaves, bark

Orangutan (Pongo) diet

Polygynous

Orangutan (Pongo) mating system

Yes

Orangutan (Pongo) sexual dimorphism (yes, no, moderate)

Resource defense

Orangutan (Pongo) method of mating competition

Southeast Asia

Gibbon (Hylobates) geographic location

Arboreal, brachiation

Gibbon (Hylobates) locomotion

Fruit

Gibbon (Hylobates) diet

Monogamous

Gibbon (Hylobates) mating system

No

Gibbon (Hylobates) sexual dimorphism (yes, no, moderate)

Low male-male competition

Gibbon (Hylobates) method of mating competition

Africa

Olive baboon (Papio anubis) geographic location

Arboreal

Olive baboon (Papio anubis) locomotion

Omnivore

Olive baboon (Papio anubis) diet