Anthropology 105 UW-Madison Exam 2 (Fall 2024)

Charles Darwin came up with a mechanism for evolutionary change. What were his three postulates that lead to evolution by natural selection?

1. There is a struggle for existence

2. There is variation in features related to survival and reproduction

3. This variation is passed from generation to generation

Why are humans not at the top of a tree of life? Why are trees of life not hierarchical?

the concept of a tree of life is not hierarchical, meaning there is no "higher" or "lower" organism; instead, it represents the branching evolutionary relationships between all living things,

Know the details of how Peter and Rosemary Grant observed evolution by natural selection in action in the Galapagos in the 1970s when there was a drought on the island Daphne Major. How did their study support Darwin's postulates?

finches with larger beaks were more likely to survive because they could access the harder, larger seeds that were the only food source available, leading to an observable shift in the population towards larger beaks in subsequent generations

What is an example of genetic bottleneck?

Some event causes a dramatic decrease in population size and diversity

Ex. Due to hunting the seal population drastically dropped and the genetic diversity became extremely limited

What is an example of founder effect?

When a small part of a population moves to a new location, the "founders" genetic diversity determines the diversity of the new population.

in 1700s 200 people moved to eastern PA (the amish) Individuals in the founder group carried an allele that causes dwarfism and therefore this genetic disorder is much more common in the amish community.

phylogeny

Evolutionary history of a species or group of species.

Primitive traits in a phylogeny

shared not only within a group but also with more distantly related groups

Derived traits in a phylogeny

newly-evolved features of a clade

Parallel evolution

Two related species that have made similar evolutionary adaptations after their divergence from a common ancestor

Convergent evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

Charles Darwin

English natural scientist who formulated a theory of evolution by natural selection (1809-1882)

Natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Mutation

A change in a gene or chromosome.

Gene flow

Movement of alleles into or out of a population due to the migration of individuals to or from the population

Genetic drift

A change in the allele frequency of a population as a result of chance events rather than natural selection.

Genetic Bottleneck

a sudden reduction in the number of alleles in a population

founder effect

change in allele frequencies as a result of the migration of a small subgroup of a population

Why do we study nonhuman primates in a class about human evolution?

1. Human are primates

2. We share recent common ancestry with other primates, we also share many similarities in anatomy and behavior

Are humans primates?

Yes

Primates are diverse in:

1. body size

2. habitat

3. diet

4. social structure and mating structure

5. activity patterns

What features do primates have in common?

1. Grasping hands and feet

2. Nails instead of claws

3. Reduced smell (olfaction)

4. Enhanced vision

5. Forward facing eyes encased in bone

6. Small litters

7. Long lifespan

8. Long gestation

What are some key features of the strepsirrhines?

- Tooth comb

- Slightly smaller brain

- Tapetum (reflective layer in back of eye)

What are some key features of the haplorrhines? (UNSURE IF TRUE)

Tarsiers:

1. Live in Asia

2. Small, nocturnal insect eaters

3. Vertical clingers and leapers

4. No toothcomb or tapetum

Are humans haplorrhines?

Yes

What features do tarsiers have in common with strepsirrhines and what features do they have in common with haplorrhines?

Like Streps:

1. Very small

2. Nocturnal

3. Highly insectivorous

4. Vertical clinger-leapers

Like Haplorrhini

1. Almost full PO closure

2. More convergent eyes

3. No rhinarium

4. Fovea

Though nonhuman primates can be found in a diverse range of habitats, they tend to be found where in the world?

What are some key features of platyrrhines?

1. live in south and central america

tropical forests

2. arboreal

3. quadrupedal though some suspensory climbers

4. some have prehensile tails

5. most have 2-1-3-3 dental formula

Within the cercopithecoids, what are key features of colobines?

1. Asia and Africa

2. Primary leaf and seed eaters

3. Arboreal

Within the cercopithecoids, what are key features of cercopithecines?

1. Mostly in Africa

2. Macaques in Asia

3. Great diversity in diet, size, habitat, social and mating strategies

What are key features of hominoids?

1. Large brains

2. Tailless

3. Suspensory, orthograde (vertical) climbers

4. Unspecialized y-5 molars

Are humans hominoids?

Yes

Nocturnal

active at night

Diurnal

active during the day

Cathemeral

Can be active during the day or night (irregular schedule)

Primate

monkeys, apes, and humans

life history

Traits that affect an organism's schedule of reproduction and survival.

haplorrhine

A subdivision within the primate order based on shared genetic characteristics; includes tarsiers, New World monkeys, Old World monkeys, and apes (including humans).

strepsirrhine

Any member of the group containing lemurs and lorises.

toothcomb

Anterior teeth (incisors and canines) that have been tilted forward, creating a scraper.

tapetum

A reflective layer of the choroid in the eyes of many animals, causing them to shine in the dark.

catarrhine

Member of Catarrhini, a parvorder of Primates, one of the three major divisions of the suborder Haplorhini. It contains the Old World monkeys, apes, and humans.

platyrrhine

a nasal classification which is short and broad and has the minimum of projection; common to individuals of African descent.

prehensile tail

A tail that acts as a kind of a hand for support in trees, common in New World monkeys.

lemur

An arboreal primate with a pointed snout and typically a long tail, found only in Madagascar.

loris

A nocturnal strepsirhine found today in Asia and Africa

galago

Small primates that live in many African forests; also called bushbabies.

tarsier

a small insectivorous, tree-dwelling, nocturnal primate with large eyes, a long tufted tail, and long hind limbs, native to the islands of Southeast Asia.

ape

Ape is a member of the primate family that includes species such as gorillas, chimpanzees, orangutans, gibbons, and humans. Apes are characterized by their large brains, lack of a tail, and more complex social behaviors compared to other primates like monkeys

hominoid

A hominoid is a member of the biological superfamily Hominoidea, which includes all apes—both great apes and lesser apes—and humans. Hominoids are a subset of primates, and they share certain traits such as the absence of a tail, a more upright body posture, larger brains compared to other primates, and a greater reliance on vision rather than smell.

Difference between "lesser apes" (hylobatids) and "great apes"

Great Apes: This group includes gorillas, chimpanzees, bonobos, orangutans, and humans. They are generally larger, have more advanced cognitive abilities, and exhibit complex social structures.

Lesser Apes: This group is primarily made up of gibbons, which are smaller and more agile, and tend to live in monogamous pairs.

monkey

a wild animal that can climb trees fast and easily

cercopithecoids

old world monkeys. tails, large brains, adaptations for quadrupedalism, bilophodont molars (4 crests)

cercopithecines

The subfamily of Old World monkeys that includes baboons, macaques, and guenons.

colobines

Common name for members of the subfamily of Old World monkeys that includes the African colobus monkeys and Asian langurs.

vertical clinging and leaping

A locomotor pattern characteristic of several primates, including tarsiers and galagos. The animal normally rests by clinging to a branch in a vertical position and uses its hind limbs alone to push off from one vertical position to another.

arboreal

living in trees

Lecture 10

Which primates belong to the group called the hominoids? Know basic information about the location, diet, and social and mating organization for each.

include lesser apes (gibbons) and great apes (orangutans, gorillas, chimpanzees, bonobos, and humans).

Lesser apes (Gibbons) Diet: Primarily frugivorous (fruit-eating), but they also consume leaves, insects, and small animals.

Great Apes:

Orangutans: Mainly frugivorous, focusing on fruits like figs and durians, but they also eat leaves, bark, insects, and small vertebrates

Gorilla: Primarily herbivorous, feeding on leaves, stems, fruits, and bamboo shoots. Occasionally, they eat insects

Chimps: Omnivorous; they eat fruits, leaves, nuts, seeds, insects, and occasionally hunt small mammals (including monkeys) for meat

Bonobos: Primarily frugivorous, but also consume leaves, flowers, and small animals

Humans: Humans are omnivorous, with diets varying greatly depending on culture, region, and availability of food. They consume a wide variety of plants, animals, and processed foods

Genus name for gorillas

gorilla

genus name for orangutans

Pongo

genus name for chimpanzees and bonobos

pan

genus name for humans

homo

species name for gorilla

gorilla gorilla

species name for chimpanzees

Pan troglodytes

species name for bonobos

Pan paniscus

species name for humans

Homo sapiens

Why is color vision adaptive for primates?

Young leaves have less fiber and are easier to digest, so being able to tell the differencebetween the red young leaf and green mature leaf means a more nutritious meal.

How is trichromacy a convergent feature in different branches of primates?

it evolved independently in Old and New World primates as an adaptation to foraging for fruit against a green background

How have different branches of primates shown different modes of adapting to low light conditions (in other words, nocturnal adaptations)?

1. Within a nocturnal setting, different dietary strategies have caused different kinds of adaptations.

2. Adaptations to nocturnality include larger eyes and functional loss of s-opsin, specialization on rod cells instead of cone cells.

Binomial nomenclature

Classification system in which each species is assigned a two-part scientific name

Linnaeus

Swedish botanist who proposed the modern system of biological nomenclature (1707-1778)

genus

A classification grouping that consists of a number of similar, closely related species

species

A group of similar organisms that can breed and produce fertile offspring.

adaptation

A characteristic that improves an individual's ability to survive and reproduce in a particular environment.

homology

A trait that is shared between two species because they both inherited it from a common ancestor.

homoplasy

A trait that evolves in common between two species that was not present in their common ancestor

convergence

is the evolution of similar traits in two species based on different structures in their common ancestor

parallelism

the evolution of similar traits in two species based on the same structure in their common ancestor

cones and rods

Cones: Cones are responsible for color vision and allow us to see in bright light

Rods: Rods are specialized for low-light (night vision) and help us see in dim lighting conditions.

opsin gene

They are integral to the conversion of light into electrical signals that the brain interprets as visual images. The genes encoding these proteins are collectively known as opsin genes. Here are some key points about opsin genes:

dichromat and dichromacy

an individual who has dichromacy, meaning they possess only two types of cone photoreceptors.

Because of this limitation, dichromats typically perceive a more restricted range of colors compared to individuals with normal trichromatic vision.

trichromat and trichromacy

refer to the condition of having three types of functioning color receptors (cones) in the retina, which allows for normal color vision.

What is the difference between proximate and ultimate causes in evolution?

Proximate: involve immediate physiological and environmental circumstances of events

Ultimate: involve historical processes that underline genetic and cultural patterns

What are "Tinbergen's four questions"?

1. How does it work

2. How does it develop

3. How does it function

4. How did it evolve

What is dietary ecology?

The study of how animals choose and acquire foods, and the effects of food on energy and nutrition

What factors determine how much food a primate needs?

1. Basal metabolic rate

2. Growth rate

3. Active metabolism

4. Reproductive effort

What relationship do we see between primate body size and primate diet? What do smaller primates tend to eat a lot of? What do the largest primates tend to eat a lot of?

Small animals eat more prey and gum/nectar (a more balanced diet). Large animals eat largely leaves. Middle eats a lot of fruit

What are primates seeking out in their diet? i.e., what are macronutrients and micronutrients? (remember another key component is also water).

Micronutrients: Vitamins, minerals

Macros: Carbs, amino acids and fats

Remember that primates get energy from macronutrients in their food: fat, carbohydrates and digestible fiber provide energy. (Protein used for energy just in emergency/starvation situations.)

N/A

What do primates avoid when finding the foods for their diet?

Toxins

What kinds of plant or animal foods do nonhuman primates tend to get their protein from? Carbohydrates? Fats?

Protein from insects and leaves

Carbs from fruit and gum

Fats from insects and seeds

What are the morphological features (body size, dentition, digestive tract) of an insectivore?

• Small body size

• Sharp cusps on teeth

• High, sharp crests of molar teeth

• Simple digestive system

What are the morphological features (body size, dentition, digestive tract) of an folivore?

• Large body size

• Small incisors

• Sharp shearing crests on molars

• Enlarged, well-developed digestive systems

What are the morphological features (body size, dentition, digestive tract) of an frugivore?

• Medium body size

• Large, broad incisors

• Low-cusped, relatively flat molars

• Relatively large digestive system, but not specialized like that found in folivores

What are the morphological features (body size, dentition, digestive tract) of an gummivores?

• Relatively small body size

• Long, robust incisors

• Claws in some

How do plants defend themselves from herbivores (plant eaters)?

Physical: Mechanical protection on surface (cactus)

Chemicals that inhibit digestion

What are two mechanisms by which plant secondary compounds repel herbivores? Hint: one of the two is chemical defenses that are toxic

1. Chemicals that inhibit digestion - for example, tannins bonds to protein and does not allow protein to be digested

2. Chemical defenses that are toxic - toxins that can kill or repel herbivores at low concentrations (ex: cyanide in apple seeds)

What is an example of a primate that has evolved adaptations to deal with high levels of toxic compound in its diet?

Multiple species of bamboo lemur eat mostly bamboo

• Bamboo plants protect themselves with a chemical called cyanide

What strategies do primates use to cope with plant secondary compounds?

• Degrade toxic components with help from symbiotic bacteria (gut microbes can help detoxify)

• Detoxification of compound in liver

• Proteins in saliva of some primates -- proline-rich salivary proteins -- form complexes to inactivate toxic compounds

What is an example of tool use in a platyrrhine?

Rocks