Human Evolutionary Biology - Final Exam

Carolus Linnaeus' three major contributions to classification are:

(1) based on natural features (2) binomial nomenclature (3) consistent hierarchical classification

What is the sequence of stone tool technologies through time and the basics of how each differs from the others.

(Lomekwian→ Oldowan→ Acheulean) Lomekwian- discovered at a site in northwestern Kenya dated to 3.3 Ma. includes cores, flakes, hammerstones, and anvils. The cores are quite large and heavy Lomekwian tools were made either by "block on block" percussion, where the core is struck against a stationary object (the "anvil"), or by "bipolar" percussion (right), where the core is placed on an anvil and struck with a hammerstone. Oldowan- tools are from a site in Ethiopia dated to 2.6 Ma.found exclusively in East Africa. After 2.0 Ma, Oldowan tools are found at sites throughout Africa and at a site in Western Asia (Dmanisi, Republic of Georgia). Are primarily composed of cores, flakes, and hammerstones. All of which are smaller and lighter than their Lomekwian counterparts. Were primarily made using "hard hammer percussion," where a hammerstone is used to knock flakes off a core. Used comes from cuts and other marks on the fossilized bones of bovids and other animals that indicate butchery. Acheulean tools are from a site in Ethiopia dated to about 1.75 Ma, and become the dominant stone tool technology at hominin sites until around 200 ka. Defining feature of the Acheulean is the introduction of relatively large, bifacial tools that have been called picks, cleavers, and handaxes. The handaxe is the iconic Acheulean tool; they are relatively large. were prepared directly from large cobble cores, but they were also prepared from very large flakes detached from giant cores.

Name different types of primate locomotion and some skeletal features associated with them

(especially intermembral index or IMI): 1. arboreal quadrupedalism (IMI = 100) 2. terrestrial quadrupedalism (IMI = 100) 3. vertical clinging and leaping (IMI < 100) 4. Suspensory (IMI > 100) 5. knuckle-walking (IMI > 100)

What is a mold?

(is some impression of a body part (or whole) left by an organism in its environment

What are the types of non-empirical evidence?

-Hearsay evidence -Revelatory evidence -Emotional evidence

Describe the process of fossilization

-The first step in the process of body fossil formation is a relatively rapid burial. The body parts of all animals will eventually decompose, decay, disintegrate, or be destroyed if exposed on the surface for long enough. -Once the organism is buried, mineralization may follow. Even after burial, different body tissues are more susceptible to decay and decomposition than others. When water infused with minerals seeps into the buried body tissues, the biochemical structure of the tissue can be replaced by the minerals in the water. -After mineralization, the original structure of the body tissue remains, but the original material largely does not. -If no part, mineralized or otherwise, of the original organism remains, a trace fossil might yet exist in the form of a mold or cast. rapid burial --> mineralization --> original structure of the body tissue remains, but the original material largely does not.

What are the distinguishing features of Paranthropus?

-cranial features suggestive of massive chewing muscles -sagittal cresting and -wide robust zygomatic arches

Define endochondral

-development, a cartilage "model" forms first and is replaced by bone

Bone development pathways: endochondral vs. intramembranous

-development, a cartilage "model" forms first and is replaced by bone -development, bone directly develops within connective tissue without a cartilage precursor

Define intramembranous

-development, bone directly develops within connective tissue without a cartilage precursor

What are the derived features of Anthropoids?

-have a fused mandibular symphysis -a fused frontal bone -have only nails, no grooming claws -With their decreased reliance on olfaction, anthropoids have flatter faces than strepsirrhines

What features does a good hypothesis have?

-logical -falsifiable -consistent with other knowledge -simple

What percentage of the DNA of living modern humans outside of Africa originated in Neanderthals?

1-3%

What are the four forces of evolution?

1. Mutation 2. Gene flow 3. Natural selection 4. Genetic drift

Define Mendel's 3 principles

1. Principle of segregation (the genetic material carrying the traits from the parents does not blend or merge together, but remains distinct and separate) 2. Principle of dominance (some alleles are dominant, while others are recessive) 3. Principle of independent assortment (the genes for different traits are inherited independently)

What are types of data used to infer diet in the hominin fossil record

1. cut marks on fossilized bones 2. tooth shape and size 3. skull size and shape 4. dental wear 5. stable isotopes

What is the dental formula of Catarrhines (Old World monkeys and apes)

2.1.2.3

Dental formula of Platyarrhines (New World monkeys )

2.1.3.3

How many varieties did Carolus Linnaeus identify?

4 varieties 1. American 2. European 3. Asiatic 4. African

When did modern humans migrate from Africa?

60,000 years ago

When did the last common ancestor of chimps and humans live?

7 mill years ago

Define evolution in genetic terms

A change in allele frequencies within a population from one generation to the next

Define natural selection

A critical component of the descent with modification hypothesis is how exactly the modifications could happen

What is a Clade?

A group of species that includes a common ancestor and all its descendants

Geographic distribution of each hominin group (which are found only in Africa vs. which groups are also found in Eurasia)

AFRICA -chimpanzees -apelike bipeds -australopithecus -Small homo -large homo -Paranthropus? (NO descendents). EURASIA -large HOMO

What is the difference between acclimatization and evolutionary (genetic) adaptation?

Acclimitization is a physiological response to changes in the environment that occur during an individuals lifetime (may be temporary or permanent, depending on the environmental change and when in the individuals life it occurs). --------------------------------------------------- adjustments during the lifetime of an individual to help maintain homeostasis in response to a stressor Developed over many generations Reflects natural selection measured through differential fertility & mortality Difficult to measure evolutionary change in humans Often focus is on extreme environments to uncover adaptive patterns Evidence for genetic adaptation to thermal stress (heat & cold), solar radiation, high altitude, infectious disease, etc. Solar radiation & skin color Body proportions & climate

Which population of living humans has the greatest genetic diversity?

Africans

Most common mode of locomotion among primates

Arboreal quadrupedalism

What is the hardest substance in the human body and the material that covers tooth crowns?

Enamel

Which bone development pathway is the most common?

Endochondral

What is a Theory?

If many scientists have tried many ways over many years to break a collection of intersecting and consistent explanations and have always failed to reject them, we begin to call this set of hypotheses a ______(answer)__.

Define Nucleotide

LECTURE 4 3 PARTS 1. sugar 2. phosphate 3. nitrogenous base

Define binomial nomenclature

Linnaeus' classification was the first to apply this is the formal species name format introduced by Linnaeus

Sequence of stone tool technologies through time from oldest to youngest

Lomekwian --> Oldowan --> Acheulean)

3 anatomical features of bipedalism and how they differ between bipeds and non-bipeds

Modern human -No brow ridges -Globular braincase -No occipital torus/bun Archaic Human -Prominent brow ridge -Oblong braincase -Occipital torus/bun is present

What is the basic building block of DNA?

Nucleotide

Populations that live in high sunlight environments are expected to have darker skin while populations that live in low sunlight environments are expected to have lighter skin.

Populations that live in high sunlight environments are expected to have darker skin while populations that live in low sunlight environments are expected to have lighter skin.

What is speciation?

The process of how an ancestral species gives rise to two descendent species

What is taphonomy?

The scientific study of how life forms are deposited and buried after death One of its major goals is to understand biases in the fossil record.

What is heredity?

The study of how traits are transmitted from parents to their offspring

How was the great rift valley of East Africa formed?

Two of the planet's continental plates have been moving away from each other for several million years, forming a crack in the Earth's surface

Define self-serving bias

We attribute our successes to our skills and efforts and our failures to external forces.

Define hindsight bias

We see past events as having been more predictable than they actually were.

Define confirmation bias

We seek out evidence that supports our beliefs and avoid contradictory evidence

What is science?

a process of understanding phenomena through observation, generalization, and verification.

Define collagen

a stretchy protein also found in cartilage, tendons, ligaments, and skin

Oldowan tools

are from a site in Ethiopia dated to 2.6 Ma.found exclusively in East Africa. After 2.0 Ma, Oldowan tools are found at sites throughout Africa and at a site in Western Asia (Dmanisi, Republic of Georgia). Are primarily composed of cores, flakes, and hammerstones. All of which are smaller and lighter than their Lomekwian counterparts. Were primarily made using "hard hammer percussion," where a hammerstone is used to knock flakes off a core. Used comes from cuts and other marks on the fossilized bones of bovids and other animals that indicate butchery.

Acheulean tools

are from a site in Ethiopia dated to about 1.75 Ma, and become the dominant stone tool technology at hominin sites until around 200 ka. Defining feature of the Acheulean is the introduction of relatively large, bifacial tools that have been called picks, cleavers, and handaxes. The handaxe is the iconic Acheulean tool; they are relatively large. were prepared directly from large cobble cores, but they were also prepared from very large flakes detached from giant cores.

Define incisors

are often used in grasping, nipping, stripping, scraping, and other ingestive behaviors that bring food into the mouth in chunks small enough to be processed by other teeth

Define molars

are used to fragment foods into ever-smaller chunks by shearing, slicing, crushing, and grinding

Define Emotional evidence

as derived from one's own subjective feelings - is not empirical because only you can experience it. a type of non-empirical evidence

Define Rationalism/Rational

based on logical reasoning

Major organic and inorganic components of bones and teeth and what they provide:

collagen (flexibility) bone minerals (stiffness)

What are the different types of biases?

confirmation, self-serving, hindsight

Skin color is patterned by latitude

darker skin in tropics; lighter in north

Define bone minerals

deposited within a collagen matrix - that gives its stiffness

Lomekwian tools

discovered at a site in northwestern Kenya dated to 3.3 Ma. includes cores, flakes, hammerstones, and anvils. The cores are quite large and heavy Lomekwian tools were made either by "block on block" percussion, where the core is struck against a stationary object (the "anvil"), or by "bipolar" percussion (right), where the core is placed on an anvil and struck with a hammerstone.

When does the race hypothesis first appear?

during the rise of the European colonialism

What is relative dating? What are the different types of relative dating methods?

earliest method of dating fossils and does not give a precise numeric date, only whether a fossil lived before or after some other fossil or other event in the past.

Define Homology

features that are shared due to shared ancestral heritage

Homology vs. Analogy

features that are shared due to shared ancestral heritage features that evolved independently for the same function

Define Analogy

features that evolved independently for the same function

Compare human vs. chimp genetic diversity

humans are less genetically diverse than chimps

When did the scientific consensus turn against the race hypothesis?

in the 1960's

Name types of teeth and their functions:

incisors, canines, premolars, molars

Define Fused frontal bone

is a fibrous joint that divides the two halves of the skull in infants and children

What is a hypothesis?

is a provisional explanation of a phenomenon. It explains observed data.

What is an allele?

is a variant of a gene

What is a fossil?

is any evidence of past plant or animal life that is preserved in the material of the Earth's crust.

Define falsifiable

is some observation or experiment that, if conducted, could give results contrary to those predicted

What is taxonomy?

is the science of classifying, naming, and describing organisms

Define stratigraphy

is the study of the sequential layering of sedimentary deposits.

What is a cast?

is what is created when a mold is filled with material that is mineralized and preserved

Why is the East African rift valley useful to paleoanthropologists?

it leads to volcanic activity along the rift exposes fossils that were previously buried

What groups form the Strepsirrhines?

lemurs, lorises and galagos

What are the major chewing muscles?

masseter and temporalis

What is absolute dating? What are the different types of absolute dating methods?

methods of dating are based on the analysis of radioactive isotopes and allow for direct estimates of the age of the sediments

What hominin species is a symbolic behavior like cave art associated with?

modern humans - Homo sapiens

Define canines

often have sharp, pointed edges for fighting or stabbing, biting, and holding prey. Human canines are incisiform and function mostly like additional incisors

Define premolars

often vary along the tooth row, with the anterior ones simpler and more canine-like and the posterior ones more molar-like with similarly variable functions

Define Skepticism/ Skeptical

questioning assumptions, evidence and explanations

Define Empiricism/ Empirical

relies on experimentation and observation

Define Post-orbital closure

ring around the eye

What is the idea of Occam's razor?

scientific preference for simple explanations

What is the Principle of dominance?

some alleles are dominant, while others are recessive

Define original lateral continuity

states that all parts of a stratum, however disrupted by later activity, were once joined in a single layer.

Define superposition

states that in an undisturbed sequence, each stratum (layer) is younger than the one beneath.

Define original horizontality

states that strata are horizontal or nearly so when they are deposited.

Define intermembral index

summarize the relations the relative length of the forelimb and hindlimb varied substantially across these locomotor categories

Explain the three core principles of stratigraphy

superposition, original horizontality, original lateral continuity

Define hierarchical

the combination of diversification by speciation and descent with modification leads to a natural hierarchical organization of living things

What is Sexual dimorphism?

the difference in size or shape between males and females of the same species

Define Anthropoids

the earliest ____ are found in the Eocene in both Africa and Asia.

Define Fused mandibular symphysis

the facial skeleton of the skull the external surface of the mandible is marked in the median line by a faint ridge

What is the Principle of independent assortment

the genes for different traits are inherited independently

What is the Principle of segregation?

the genetic material carrying the traits from the parents does not blend or merge together, but remains distinct and separate

What is clinal variation?

the gradual and continuous change in a trait or feature over geographic space

What is Darwin's major contribution to evolutionary theory?

the natural selection hypothesis

The environments each hominin group is found in 1. Ape-like bipeds: 2. Australopithecus: 3. Paranthropus: 4. Small Homo: 5. Large Homo:

tropical woodland/ forest mosaic of open and wooded areas mosaic of open and wooded areas more open habitats a broad variety of habitats ranging from tropical to temperate grasslands and woodlands.

Define Hearsay evidence

what someone says they heard another say - is not good scientific data unless you can verify it. a type of non-empirical evidence

Define Revelatory evidence

what someone says was revealed to them by a deity - is not empirical because you cannot verify it. a type of non-empirical evidence

Scientific thinking is based on what 3 major components?

• Empiricism/ Empirical (relies on experimentation and observation) • Rationalism/Rational (based on logical reasoning) • Skepticism/ Skeptical (questioning assumptions, evidence and explanations)