Bio Anth 101 Study Guide
Foramen magnum
"Big hole"; located on the inferior region of the skull
What are some of the important features associated with the fossil "Lucy" (e.g., age, location, significance)?
"Lucy": Represents nearly 40% of a complete skeleton; ~3.2 mya, found in Ethiopia
Based on fossil evidence, in what ways are "Selam" and Lucy considered "ape-like" and "human-like"?
"Selam" and Lucy are both "ape-like" in their upper body morphology (e.g., arm length, shoulder blade structure), indicating that they spent some time climbing, swinging, and living in the trees. "Selam" and Lucy are also both "human-like" in their lower body morphology (e.g., pelvis), suggesting that they were bipedal and walked upright.
What are some of the important Homo erectus fossils and sites?
- Zhoukoudian, China: Site with the remains of around 40 individuals that was occupied intermittently from 600,000-200,000 years ago -Skullcaps from Ngandong, Java originally dated to ~50,000 years ago NOTE: These dates have been updated to 546 - 143,000 years -Cranium of a child from Mojokerto, Java dated to ~1.8 mya -Fossils from the site of Dmanisi, Republic of Georgia, dated to ~1.8 - 1.7 mya
One of the oldest modern human fossil sites found in Herto, Ethiopia is dated to approximately: a) 160,000 years old b) 780,000 years old c) 300,000 years old d) 40,000 years old e) 18,000 years old
160,000 years old
What is developmental plasticity/acclimatization? How does this mode of adaptation work? When do these adaptations occur? What are some examples of developmental plasticity/acclimatization?
2) DevelopmentalAcclimatization/Developmental Plasticity ▪ Long-term, irreversible changes that result from exposure to environmental stressors during growth and development ▪ General Objective: To fine-tune an individual's physiology during development to match the local ecological conditions ▪ Affects a range of biological systems ▪ Endocrinefunction ▪ Metabolism ▪ Cardiovascularreactivity ▪ Neurological development
What is "precision grip"? Why is this skill important for early Homo evolution?
Ability to grip objects forcefully with hands. Requirement for making tools
According to the paleoanthropologist Daniel Lieberman, why did human ancestors become bipedal?
According to Daniel Lieberman, human ancestors became bipedal because this form of locomotion (compared to quadrupedalism) increased energetic efficiency.
Of the Australopithecine species, which one is the best-known early hominin?
Australopithecus Afarensis
Based on current evidence, how did Homo floresiensis evolve a small body size?
Based on current evidence, Homo floresiensis evolved a small body size due to "island dwarfism". Through this process, mammals have the capacity to reduce their body size due to isolation and lack of resources on an island.
What are cranial endocasts?
Cranial endocasts are casts of the cranial cavity, which show the size and shape of the brain as well as certain details of the brain's outer surface.
What is the significance of the "Taung Child" fossil (e.g., age, morphological characteristics)? Who discovered this fossil? When was it found?
Discovered by Raymond Dart (Australian anatomist) • Found in 1924 • Dated to ~2.3 mya • Intermediate between apes and humans A. africanus
What is the significance of the footprints found in Laetoli, Tanzania? According to the fossil evidence, which hominin group created these footprints?
Footprints: ~75 foot trail, dated to ~3.6 mya, Fossils at the site linked to A. afarensis; 2 (or 3) individuals walking bipedally
The presence of a chin is a characteristic of: a) Ardipithecus b) Homo sapiens c) Australopithecus afarensis d) Neanderthals e) Homo erectus
Homo sapiens
Who made the cave art during the Pleistocene in Europe (e.g., Lascaux)? a) Homo neanderthalensis b) Homo sapiens c) Homo heidelbergensis d) Homo erectus e) Australopithecus afarensis
Homo sapiens
You find a fossil hominin skeleton in North America that dates to approximately 10,000 years ago. What species does this most likely to belong to? a) Homo neanderthalensis b) Homo sapiens c) Homo erectus d) It could be either Homo neanderthalensis or Homo sapiens (modern humans) e) It could be either Homo erectus or Homo sapiens (modern humans)
Homo sapiens
This fossil site, discovered by Mary Leakey in Tanzania, preserves an incredible set of hominin footprints: a) Olduvai b) Laetoli c) Hadar d) Taung e) Piltdown
Laetoli
Post-orbital constriction
Narrowing behind the orbits
The first evidence of possible burial of the dead is associated with: a) Homo erectus b) Homo habilis c) Neandertals d) Paranthropus genus e) Homo floresiensis
Neandertals
According to this class, Homo heidelbergensis was the likely ancestor of: a) Homo erectus only b) Neandertals only c) modern humans only d) Neandertals and modern humans e) all answers are correct
Neandertals and modern humans
Outside of Africa, where have the oldest Homo erectus fossils been found?
Oldest fossils found in Dmanisi, Georgia
What is "persistence hunting"?
Persistence hunting is the ability to hunt for long periods of time over long distances, particularly during the mid-day sun.
Nuchal
Posterior side of the neck
How does Homo floresiensis (nicknamed "The Hobbit") inform our understanding of the dispersal of Homo erectus from Africa?
The discovery of Homo floresiensis suggests that Homo erectus migrated into areas of Indonesia (e.g., the island of Flores). Specifically, this finding demonstrates the great distance by which Homo erectus dispersed into other regions of the world.
What is the significance of the fossil named "Selam"?
The fossil discovery of "Selam" was significant because it revealed bones of a small female skull that was clearly a hominin and not a non-human primate (e.g., chimpanzee). This discovery helps to illuminate hominin evolution in a unique way.
A sagittal crest is: a) only present in gorillas and chimpanzees b) a characteristic of Paranthropus c) indicative of bipedalism d) not present in any hominin fossils e) indicative of an arboreal lifestyle
a characteristic of Paranthropus
What accounts for skin color variation?
geographical location
The specialized cranium and teeth of the robust Paranthropus genus are thought to be an adaptation to: a) colder temperatures b) higher altitude c) low quality diet of gritty, tough fibrous foods d) more efficient bipedal locomotion e) a specialized, carnivorous diet focused on meat-eating
low quality diet of gritty, tough fibrous foods
In reference to "race", does biology equal genetics?
no
Australopithecus africanus ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available) ▪ The ways in which the fossil is more ape-like or human-like
• Age: ~3.0 - 2.4 mya • Location: Sterkfontein, Taung and Makapansgat, South Africa • Habitat: Woodlands and savannas • Cranium: • Smallbrain(450-500cc) • Small canines and incisors • Lessprognathicface • Postcranium: Similar to A. afarensis • Bipedaladaptations(curvedvertebrae) • Somearborealadaptations(longarms)
Did Neandertals interact with modern Homo sapiens? What evidence supports these ideas? What hypotheses have been proposed to explain the fate of Neandertals?
• Between 30 - 40,000 years ago, Neandertals were joined in Europe by anatomically modern Homo sapiens -genetic evidence indicates occasional interbreeding • Various hypotheses regarding the fate of Neandertals • Examples: Parasites and pathogens, competitive replacement, failure or inability to adapt to climate change
Multiple Dispersals and Assimilation
• Most supported and accepted view now - Multiple dispersals of genus Homo out of Africa • "OutofAfrica,AgainandAgain" - Modern humans originated in Africa, ventured out, and interbred with populations of archaic Homo sapiens • Evidence: - Recent fossil and DNA evidence support this view
What type of stone tool technology did Neandertals use? How are these tools made, and how are they used?
• Neandertals were skilled toolmakers and proficient big- game hunters • Used more complex tools: Mousterian industry • Found in Europe, Western Asia, and North Africa • Levallois technique: Flakes struck from prepared cores • Produced good flakes with little effort • Hand axes replaced by crafted flake tools • Evidence of hafting • Able to hunt large game (e.g., bison, deer) in coordinated groups using long spears
What is nonconcordance, and how does this concept affect our understanding of racial classification systems?
• Nonconcordance: Different traits do not share the same patterns of variation across geographic space • Traits are not linked as a package • Different traits = Different clustering
What changes occurred in the climate during the Middle Pleistocene (900 -130 kya) and Late Pleistocene (130 - 10 kya)? During this time, what were the effects of climate change on hominin evolution?
• Rapid climatic fluctuations occurred during the Middle Pleistocene (900 -130 kya) and Late Pleistocene (130 - 10 kya) • Glaciations: Associated with colder temperatures and continental ice sheets covering northern continents • Interglacials: Associated with warmer temperatures and reduction in continental ice sheets • Major effects in Europe and northern Asia; influenced gene flow and drift
Human developmental plasticity
▪ 19th century studies document variation in growth based on socioeconomic factors ▪ Reflection of environmental factors experienced during growth and development ▪ Franz Boas's Immigrant Studies (1912) ▪ European-born immigrants and their American-born children ▪ Recognition of "plasticity" of humans ▪ Secular trends: Changes in phenotype that occur over generational time ▪ Not genetic changes but environmental shifts
What are the biological consequences of "race"?
▪ Biology≠Genetics ▪ Categorizationbysocialracecanaffecttreatmentbyothersand opportunities, which can affect biology ▪ Conscious perception of discriminatory acts ▪ System of structured inequalities
The modern synthesis
▪ Merging of natural selection with genetics (the synthetic theory of evolution) ▪ Bridging microevolution and macroevolution ▪ Focus on populations: Interbreeding groups of individuals ▪ Variable populations instead of fixed types ▪ Populations evolve, individuals do not ▪ New definition of evolution: Change in allele frequencies over generational time -Theodosius Dobzhansky -Ernst Mayr -George Gaylord Simpson
Initially, what did the field of physical anthropology study?
▪ Physical anthropology begins as the study of modern human variation.
What are some of the key morphological characteristics used to interpret and classify hominin fossils?
Defined by habitual bipedal adaptation
When did Homo erectus leave Africa? To where did they disperse?
Homo erectus left Africa ~1.8 mya Dispersed to Asia and Eurasia (Central and Western)
How did Homo erectus "pay" for the costs of encephalization?
Homo erectus paid for the costs of encephalization by consuming a high calorie diet that consisted of meat and meat byproducts.
The fossils from Indonesia that date to as recent at 12,000 years ago and belong to a hominin with a small body and a small brain (the "hobbits") are believed to represent a relatively new species known as: a) Homo heidelbergensis b) Homo erectus c) Homo neanderthalensis d) Homo floresiensis e) Homo tolkienensis
Homo floresiensis
Based on recent evidence, when and why did Homo erectus leave Africa?
Recent evidence suggests that Homo erectus left Africa approximately 1.8 million years ago and may have been motivated to leave due to their animal-based food sources (e.g., game animals) migrating into other continents. The animal migration may have been driven by climate changes, which spread grasslands from Africa into Eurasia.
What types of "big questions" can be answered from this fossil discovery?
The nearly complete fossil discovery allows scientists to answer "big questions" about Homo erectus, such as: What did Homo erectus look like? How and at what rate did Homo erectus grow and develop during early life?
How did the shrinking of rainforests and gradual drying out of Africa affect the evolution of bipedalism?
The shrinking of rainforests and gradual drying out of Africa affected the evolution of bipedalism because early hominins needed to walk farther between food patches. Thus, walking bipedally across long distances was more energetically efficient that walking quadrupedally, which uses ~4 times more energy.
When and where did the earliest hominins evolve?
~5-7 million years ago (End of Miocene), Evolved in Africa and were there exclusively until ~2 mya
Sahelanthropus tchadensis is a hominin found in Northern Chad, Central Africa. Approximately when did this hominin exist? a) ~1 - 2 million years ago b) ~2 - 3 million years ago c) ~3 - 4 million years ago d) ~6 - 7 million years ago e) ~8 - 9 million years ago
~6 - 7 million years ago
What is "isolation by distance", and how does it affect human genetic diversity?
• "Isolation by Distance": High gene flow between geographically close populations • People tend to be more genetically (and phenotypically) similar to people who live near them than to people who live farther away
Australopithecus sediba ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available) ▪ The ways in which the fossil is more ape-like or human-like
• Age: ~1. 95 - 1. 78 mya • Location: Malapa site in South Africa • Intermediate link between A. africanus and genus Homo • Cranium: • Small brain (~420 cc) • Small teeth, similar to Homo • Postcranium: Mixture of features • Human-like pelvis • Mosaic foot
Paranthropus robustus ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available) ▪ The ways in which the fossil is more ape-like or human-like
• Age: ~2.0 - 1.5 mya • Location: 4 sites in South Africa • Cranium: • Smallbrainsize(~530cc) • Pronounced sagittal crest • Flarred zygomatic arches • Flat face • Small incisors and canines • Postcranium: • Long arms but bipedal feet • Similar hands to later hominids
Australopithecus garhi ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available) ▪ The ways in which the fossil is more ape-like or human-like
• Age: ~2.5 mya • Location: Bouri site in Ethiopia • Similar to A. afarensis yet distinct dentition • Cranium features • Largepremolarsandmolarswiththick enamel • Relatively large canines • Parallel dental arcade • Prognathic face
What was the context of early race studies?
▪ Physical anthropology initially a technique for documenting variation ▪ Not a theoretically-based science aimed at understanding variation
When in evolutionary history did "Selam" exist? How have scientists determined this date?
"Selam" existed ~3.3 million years ago. Scientists determined this date based on volcanic ash found below the fossil discovery, which was aged to ~3.4 million years ago.
How have scientists classified "Selam" (i.e., to which hominin group does the fossil belong")?When in evolutionary history did this hominin species exist?
"Selam" has been classified as Australopithecus afarensis.This hominin species existed ~ 3 - 4 million years ago.
Gracile vs. robust
(gracile) Slender bodied (versus robust)
Supraorbital torus
(plural: tori): Robust piece of bone above orbits - Variability in prominence of brow ridge
Carotene, hemoglobin, and melanin (melanocytes)
-Carotene: Yellow (least important) ▪ Hemoglobin:OxygentransportingproteininRBCs ▪ Oxygenated hemoglobin with reddish hue (pink tint to light skin) ▪ Deoxygenated hemoglobin with purplish color (bluish tint to light skin) ▪ Melanin:Brown-blackpigment ▪ Produced by melanocytes (specialized immune cells in epidermis)
What are the important features associated with the Homo floresiensis fossil (e.g., age, location, brain and body size, cranial and postcranial characteristics, significance)?
-Discovered in 2004 Age:~100-12kya -Location:Flores,Indonesia Traits: -Tiny body (~3 ft.) and brain (~400 cc) -Skeletal similarities link H. floresiensis to H. erectus • Large supraorbital torus and thick cranial bones • Homo dentition • Human-like bipedal adaptations and modern proportions -Result of isolated dwarfism?
What types of models have been proposed to explain the origins of modern humans? Based on current evidence, which model is the most supported and accepted?
-Multiregional Evolution/Continuity -RecentAfricanOrigin/ "Out of Africa" -Multiple Dispersals & Assimilation most accepted is the multiple dispersals and assimilation
Where are the earliest modern human fossil sites? What are the dates of these fossils?
-Qafzeh & Skhūl (Israel; ~80,000-110,000 ya) -Herto Bouri (Ethiopia; ~160,000 ya) -Klasies River Mouth (S. Africa; ~60,000-118,000 ya) -Omo Kibish Formation (Ethiopia; ~190,000 ya) -Earliest fossils in Africa & Middle East (80,000- 190,000 ya), followed by Eurasia, Australia, and finally the Americas
What is acclimatization? How does this mode of adaptation work? When do these adaptations occur? What are some examples of acclimatization?
1) Acclimatization: Short-term, reversible systems ▪ Provide important buffering mechanisms to maintain internal stability (i.e., homeostasis) ▪ Examples: ▪ Tanning as a response to solar radiation ▪ Increased sweating ability in hot climates ▪ Increased heart rate and BMR at high altitude
Modern humans are first found approximately 190,000 years ago in which location? a) Middle East b) Eastern Africa c) Southern Africa d) Western Africa e) Southern Africa
Eastern Africa
As discussed in the video, which hominin species evolved approximately 2 million years ago?
Homo erectus evolved approximately 2 million years ago.
How did Michel Brunet become successful in finding Sahelanthropus tchadensis (nicknamed Toumaï)?
Michel Brunet was successful in finding Sahelanthropus tchadensis because he decided to move away from the Great Rift Valley in East Africa and look for fossils in Chad in Central Africa.
Which tool industry do we associate with H. neanderthalensis? a) Oldowan tool industry b) Mousterian tool industry c) Aurignacian tool industry d) Upper Paleolithic tool industry e) Acheulean tool industry
Mousterian tool industry
The condition in which the lower first premolar is sharpened from rubbing against the upper canine is known as the: a) honing/shearing complex b) crushing complex c) diastema complex d) dental arcade complex e) grinding complex
honing/shearing complex
Muscle attachment sites for chewing
human= muscle attached to temporal region chimpanzee= muscle attached to top of head
The Australopithecus afarensis fossil named "Lucy" is important because she: a) is the most complete early Homo specimen found to date b) is the first South African hominin fossil c) is a 40% complete Australopithecus skeleton d) has a brain as large as H. sapiens e) has been dated to ~6 - 7 million years old
is a 40% complete Australopithecus skeleton
Which of the following is NOT a cold adapted trait found in Neandertals? a) wide nasal opening b) barrel-shaped rib cage c) longer spears for hunting d) shorter limbs - Allen's Rule e) robust, large-sized bodies - Bergmann's Rule
longer spears for hunting
Australopithecus afarensis dates to approximately 3.0 - 3.9 million years ago and is defined by the following features EXCEPT: a) orthognathic face b) thick molar enamel c) prognathic face d) anteriorly placed foramen magnum e) small brain size
orthognathic face
Post-cranial features of Australopithecus afarensis include the following EXCEPT: a) pelvic morphology associated with bipedalism b) lower limb proportions intermediate between ape and human c) short arms d) curved phalanges e) presence of a valgus angle indicative of bipedalism
short arms
The body size and limb proportions of Homo erectus suggest that it was a) still living in the trees b) still very chimpanzee-like c) similar in size to modern day, tropically-adapted human populations d) relying on Oldowan tool use e) none of these answers are correct
similar in size to modern day, tropically-adapted human populations
Australopithecus anamensis dates to approximately 3.9 - 4.5 million years ago and is defined by the following features EXCEPT: a) small molars b) thick molar enamel c) slight honing/shearing complex d) bipedal modifications in lower limbs e) none of these answers are correct
small molars
The robust piece of bone above the orbits is known as: a) supraorbital torus b) nuchal area c) foramen magnum d) cranial crest e) post-orbital constriction
supraorbital torus
One of the most significant implications of the Taung child (Australopithecus africanus) discovery by Raymond Dart was that it demonstrated: a) that hominin encephalization evolved before other primitive ape-like characteristics disappeared b) that bipedalism evolved before hominin encephalization c) that hominin children were cave painting geniuses d) that encephalization and bipedalism evolved simultaneously in hominin history e) that it shared most of its morphological features with the Piltdown fossil
that bipedalism evolved before hominin encephalization
How do scientists need to understand "how race becomes biology"?
the treatment that the different races receive and the adaptions to their environments effects the person
Orrorin tugenensis dates to approximately 6 million years ago and is defined by the following features EXCEPT: a) thin molar enamel b) partial honing canine c) long femoral neck length d) curved hand bones e) femoral angle (i.e., valgus angle) indicative of bipedal locomotion
thin molar enamel
Neandertal burials ____________. a) are much more elaborate than modern human burials from the same time period b) are known only from Eastern Africa c) do not contain obvious evidence of ritual (e.g., grave goods) d) typically contain some grave goods and deliberate positioning of the dead e) Neandertals did not bury their dead
typically contain some grave goods and deliberate positioning of the dead
What are the differences between describing and understanding human variation?
understanding human variation means we ask and answer questions like "Why do we see a range of phenotypic variation in living humans today without much genotypic variation?" when describing human variation all we see do is look at phenotype to label and categorize ourselves
Paleoecological data suggest that Ardipithecus ramidus predominately lived in which type of habitat: a) woodlands/forests b) savannahs c) cities d) swamplands e) none of these answers are correct
woodlands/forests
Based on present fossil evidence, the earliest (i.e., oldest) possible hominins are thought to be approximately __________ years old. a) 100,000 - 200,000 b) 1 - 2 million c) 2 - 3 million d) 6 - 7 million e) 10 - 12 million
6 - 7 million
According to the primatologist Richard Wrangham, how did fire and cooking influence the morphological and physiological characteristics of Homo erectus?
According to Richard Wrangham, the use of fire and cooking among Homo erectus may have led to the evolution of smaller teeth, jaws, and digestive tracts.
The Acheulean tool industry differs from the Oldowan in which of the following ways? a) Acheulean tools are only made from volcanic rock (i.e., obsidian) b) Acheulean tools incorporate symmetrical bifacial handaxes c) The Oldowan tools contained sophisticated blades d) Oldowan tools are far more complex e) Acheulean tools incorporate the core-and-flake technique
Acheulean tools incorporate symmetrical bifacial handaxes
Current evidence indicates that the earliest anatomically modern Homo sapiens fossils are from: a) China b) Africa c) Germany d) France e) Canada
Africa
What are the key differences between Homo erectus fossils from Africa and Asia (e.g., age, location, morphological characteristics)?
African • ~1.8mya-800kya • East & South Africa • Separate species: Homo ergaster? • Large brain (~750-900 cc) • Lack of sagittal keel • Less robust supraorbital torus • Thinner cranial bones Asian • ~1.8mya-143kya -West, East & SE Asia (Java, China) "Classic" H. erectus traits -Large brain (~750-1250 cc) Strong sagittal keel -Strong supraorbital torus Thick cranial bones
Prognathism
Anterior projection of the mid- face (vs. orthognathic)
What tool industry is most closely associated with Homo erectus? a) Upper Paleolithic b) Makita c) Acheulean d) Oldowan e) No stone tools have been found with Homo erectus
Archeulean
This fossil hominin from the Middle Awash region in northern Ethiopia is from 4.4 - 5.8 million years ago and is reconstructed as a biped, but it has a grasping big toe. a) Australopithecus b) Homo habilis c) Homo floresiensis d) Ardipithecus e) Paranthropus
Ardipithecus
How have fossil discoveries from Dmanisi, Georgia informed our understanding of the dispersal of Homo erectus from Africa?
Fossil discoveries in Dmanisi, Georgia suggest that Homo erectus dispersed from Africa significantly earlier than originally estimated.
Why are fossils like "Selam" and Lucy important for understanding evolution?
Fossils like "Selam" and Lucy are important for understanding evolution because they represent an amalgam (i.e., mixture) of ape- and human-like characteristics, demonstrating both arboreal and terrestrial adaptations.
Functional adaptations: Developmental plasticity/acclimatization and acclimatization
Functional Adaptations ▪ Phenotypic modifications during the lifetime of an individual to help maintain homeostasis in response to a stressor
How did fire and cooking influence the social behavior of our early ancestors?
Furthermore, Homo erectus lived on the ground (rather than the trees) and may have used fire for protection. The use of fire and cooking may have also brought early ancestors together and facilitated the capacity for cooperation.
Where is the Great Rift Valley, and why is this site important for hominin evolution?
Great rift valley was formed ~8 mya, stretches ~3,500 miles, over 2,000 feet deep, SE Africa, runs through Tanzania, Ethiopia, Eritrea, Yemen, Kenya, Zimbabwe, Zambia. Origin of a lot of ancient hominid evidence.
During hominin evolution, what were the advantages of hairless bodies?
Hairless bodies are advantageous during mid-day sun because they decrease the risk of overheating. Hairless bodies also allow for effective sweating, which cools down the body.
Historically, what has been the dominant paradigm to describe human variation?
Historically, the dominant paradigm has been race and racial classification ▪ Used in many different ways: ▪ Continental ancestry ▪ Nationality ▪ Religious identity ▪ Ethnic or cultural group ▪ Race is often used in a social sense and can have biological consequences
Which hominin most likely used Oldowan tools? How are Oldowan tools made, and how are they used? When did they first appear in the fossil record?
Homo Habilis. • Commonly regarded as first stone tools in the archaeological record • ~2.5 mya • Involve simple modifications • Potentially associated with increased meat eating • Core: • Possibly used for heavy-duty chopping, butchering, and fracturing (e.g., bones) • However, some suggest that the core was not the main tool • Flake: • Likelyusedforcutting,slicing,and sawing (e.g., wood, meat, grass)
According to this class, who was the first hominin species to disperse out of Africa? a) Homo habilis b) Australopithecus afarensis c) Homo erectus d) Paranthropus genus e) Homo sapiens
Homo erectus
According to this class, which was the first (i.e., earliest) hominin species with definitive evidence of stone tool use? a) Homo sapiens b) Homo habilis c) Ardipithecus ramidus d) Homo erectus e) Homo floresiensis
Homo habilis
Honing/shearing complex: Sectorial premolar and diastema
Honing/Shearing Complex: Lower first premolar is sharpened from rubbing against the upper canine - Leads to honing of surfaces on both teeth - Sectorial premolar: First lower premolar that exhibits compression due its role as a shearing surface - Diastema: Space separating teeth of different functions - Reduced among early hominin groups
Tooth enamel: Thick vs. thin
Human= thick for grinding and crushing chimpanzee= thin for sheering and slicing
What has sequencing of Neandertal nuclear DNA taught us? a) Neandertals and modern humans interbred b) Neandertals were incapable of symbolic thought c) It shows that Neandertals may have had dark skin d) Neandertals had a high incidence of rickets e) Neandertals were incapable of tool use
Neandertals and modern humans interbred
Based on recent evidence, is "race" a biologically meaningful way to describe and understand human variation? Why is the term "race" problematic?
No, theres so many variations we don't take into account. It creates divides. ▪ Biologically inaccurate ▪ Not useful for classification or understanding ▪ It is has historical baggage
How do modern hunting practices (e.g., those used by the !Kung San from the Kalahari Desert) inform our understanding of this technique?
The !Kung San from the Kalahari Desert practice persistence hunting and are able to hunt for long periods of time during the mid-day sun. The bushmen hunters also demonstrate effective sweating and evaporative cooling mechanisms, allowing them to engage in persistence hunting.
What is the "Molecular Clock", and how does it work?
The "Molecular Clock" accounts for the rate of change in DNA sequences, which is relatively constant over time. This process allows scientists to compare the DNA of closely related species to ascertain how long ago they split from a common ancestor.
What does the "Molecular Clock" reveal about our last common ancestor with chimpanzees?
The "Molecular Clock" reveals that humans shared a last common ancestor with chimpanzees ~ 5 - 7 million years ago.
Why is this area of the world important for understanding the origins of human evolution?
The Great Rift Valley is an important area of the world for understanding the origins of human evolution because it is a massive geological feature characterized by active volcanoes and earthquakes over millions of years. As a result, many layers of sediments, rocks, and fossils are exposed in the Great Rift Valley. Moreover, the high frequency of volcanic activity in the Great Rift Valley allows for accurate dating of fossil discoveries.
In what type of climate and environment did the ancestors of "Selam" and Lucy live?
The ancestors of "Selam" and Lucy lived in wet, tropical, rainforest environments in Africa.
Which hominin group is associated with the first stone tools? When did this species exist?
The hominin group associated with the first stone tools is Homo habilis. This hominin species existed ~1.6 - 2.5 million years ago.
How do these hypotheses differ from traditional views of human evolution?
The hypothesis of climate instability driving human evolution differs from traditional views, which emphasize that the driving force of human evolution was the savanna environment.
What do the stone tools used by Homo erectus indicate about the intelligence of this species?
The stone tools used by Homo erectus suggest that they could plan and make decisions. Moreover, they had knowledge of the properties of stone and how it can be used.
What evidence has been used to understand brain development in early human ancestors?
To understand brain development in early human ancestors, cranial endocasts have been used. Cranial endocasts are casts of the cranial cavity, which show the size and shape of the brain as well as certain details of the brain's outer surface. Cranial endocasts suggest that the brain of "Selam" (at age three) was approximately 75% of the adult brain size. In contrast, chimpanzees have over 90% of the adult brain size by age three.
What is the significance of Turkana Boy?
Turkana Boy represents a nearly complete Homo erectus fossil.
What do Turkana Boy's teeth indicate about his age? What does this evidence suggest about the growth rate of Homo erectus?
Turkana Boy's teeth indicate that he was approximately 8 years old when he died. This estimate differs from previous suggestions that Turkana Boy died at 14 years of age. Thus, based on estimates of age (8 years) and height (5'3"), scientists suggest that Turkana Boy experienced a unique rate of growth. Specifically, these findings suggest that Homo erectus experienced an intermediate rate of growth, whereby members of this species grew faster than modern humans but slower than great apes (e.g., chimpanzees).
The basic name for the tool industry that is associated with modern humans is? a) Upper Paleolithic b) Mousterian c) Acheulean d) Oldowan e) Levallois
Upper Paleolithic
What information about brain evolution can be learned from cranial endocasts?
Using cranial endocasts, scientists can learn about the evolution of specific brain regions, for example those involved with memory, executive functioning, and the motor aspects of speech.
How are scientists using lice to understand when human ancestors lost their body hair?
When human ancestors had extensive amounts of body hair, one type of lice was present. Over time, our hominin ancestors only had hair on their heads and pubic areas, which resulted in two different types of lice: public lice (from gorillas) and head lice (the original lice that migrated to the head). Using the "Molecular Clock", scientists have examined the divergence of the two types of lice to determine when our hominin ancestors lost their body hair. Estimates suggest that the two types of lice diverged approximately 3 million years ago.
Which of these cranial features does NOT belong to Homo neanderthalensis? a) long, football-shaped cranium b) midfacial prognathism c) a chin d) wide nasal aperture/opening e) occipital bun
a chin
The following traits/adaptations are thought to have helped anatomically modern humans expand into marginal environments and replace Neandertals except: a) cultural adaptations that allowed for more efficient exploitation of the environment b) more sophisticated hunting techniques c) a larger brain d) greater dietary diversity e) more sophisticated tools for acquiring food resources
a larger brain
Which of the following is found in the fossil record associated with modern humans? a) long range weapons (e.g., atlatl) for hunting b) paintings c) sewing needles d) evidence of symbolism e) all answers are correct
all answers are correct
The Upper Paleolithic is a cultural period that: a) began in Europe around 40,000 years ago b) saw the manufacture of the first stone tools ever c) is most associated with Neandertals d) is most associated with Homo habilis e) began in England around 2,000 years ago
began in Europe around 40,000 years ago
When trying to assess if a fossil could be an early hominin, paleoanthropologists look for evidence of what key hominin trait? a) loss of body hair b) a large brain c) bipedalism d) language e) modern human limb proportions
bipedalism
Based on body size and proportions it seems likely that Neandertals were biologically adapted to a ______________ environment. a) desert b) hot-dry c) cold d) high altitude e) high sunlight
cold
Cultural innovations found in association with Homo erectus sites include: a) cave paintings b) bow and arrows c) clothing d) atatls (spear throwers) e) control of fire
control of fire
The key adaptation that differentiates Paranthropus from Australopithecus is: a) large body size and muscularity in Paranthropus related to hunting b) efficient locomotion in Paranthropus related to long distance travel c) hairiness in Paranthropus related to coping with the cold South African climate d) dietary adaptations (e.g., in the teeth and jaws) in Paranthropus for processing tough foods e) a long thumb in Paranthropus that facilitated tool-making
dietary adaptations (e.g., in the teeth and jaws) in Paranthropus for processing tough foods
We know that Ardipithecus ramidus was bipedal based on the presence of which of the following characteristics: a) foramen magnum is posteriorly located (i.e., toward the back of the skull) b) foramen magnum is anteriorly located (i.e., toward the front of the skull) c) absence of a valgus angle in the femur d) grasping big toe e) none of these answers are correct
foramen magnum is anteriorly located (i.e., toward the front of the skull)
What climatic events characterized the Middle and Late Pleistocene? a) glacial and interglacial periods b) periods of intense earthquakes c) constant volcanic activity d) constant meteor showers e) seasons comparable to those in the Northeast region of North America
glacial and interglacial periods
Australopithecines are characterized by having the following features EXCEPT: a) large-bodied (5 - 6 feet tall) b) large molars with thick enamel c) morphological changes associated with bipedal locomotion d) limited use of tools and culture e) small canines and a reduced honing complex
large-bodied (5 - 6 feet tall)
The Multiregional Evolution/Continuity model of modern Homo sapiens origins: a) proposes that modern humans did not evolve solely in Africa b) proposes that pre-modern populations in Europe, Asia, and Africa all evolved into modern humans c) is the best accepted model for explaining the origin of modern humans d) proposes that modern humans did not evolve solely in Africa AND proposes that pre-modern populations in Europe, Asia, and Africa all evolved into modern humans e) all answers are correct
proposes that modern humans did not evolve solely in Africa AND proposes that pre-modern populations in Europe, Asia, and Africa all evolved into modern humans
The current "big picture" of hominin evolution suggests that: a) there was minimal hominin species diversity, with only one species alive at a time b) hominin evolution was a linear trajectory with one hominin species giving rise to another c) there was substantial hominin species diversity, with multiple species alive at a time d) hominin evolution is extremely simple and uncomplicated e) none of these answers are correct
there was substantial hominin species diversity, with multiple species alive at a time
Homo habilis ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available)
• " The Handy Man" • Age: ~2.0 - 1.6 mya • Location: East & South Africa • Encephalization: Expanded brain size (~503 - 661 cc) • Body Size: Similar to Australopithecus • Teeth: Larger incisors, smaller molars • Precision Grip: Ability to grip objects forcefully with hands - Requirement for making tools (Oldowan tool technology)
In what ways did Homo erectus "commit to a cultural way of life" (e.g., lifestyle, behavior, use of shelter and fire)?
• "Hunting-gathering" lifestyle • High-energy food sources (e.g., animal protein) needed for higher energetic requirements • Cooperative social living, behavioral flexibility, and extended period of learning • May have built temporary shelters • In times of cold or wet weather • First definitive evidence of controlled fire (~500 - 300 kya) • Somesuggestthatfireandcookingoffood influenced social and behavioral changes • Complex tools ( Acheulean Tool Industry)
Paranthropus boisei ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available) ▪ The ways in which the fossil is more ape-like or human-like
• "Hyper-robust" form • Age: ~2.3 - 1.3 mya • Location: Ethiopia, Tanzania & Kenya, E. Africa • Cranium: • Smallbrainsize(~410-530cc) • Pronouncedsagittalcrest • Flaredzygomaticarches • Broad,dish-shapedface • Very large molar teeth, with reduction in incisors and canines • Parabolic dental arcade
Recent African Origin/"Out of Africa"
• Anatomically modern humans evolved in Africa (~150 - 200,000 years ago) and then ventured out of Africa and globally dispersed • RAO-Replace: Modern humans replaced archaic humans with minimal interbreeding • RAO-Hybrid: Modern and archaic humans engaged in interbreeding • For this to be true: • HomoerectusleftAfrica,inhabitednew regions and became reproductively isolated • ModernhomosapiensaroseonlyinAfrica and then migrated out • Modernphenotypichumanvariationis relatively recent • Evidence: • Earliestmodernhumanfossilsfoundin Africa • Mitochondrial DNA (mtDNA) • Studies among living populations show greatest mtDNA diversity in Africa
focus on the skull and era of measurement
▪ Field moves towards focus on the skull, era of measurement, and explicit hierarchy/ranking (Blumenbach)
Australopithecus anamensis ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available) ▪ The ways in which the fossil is more ape-like or human-like
▪ First Australopithecine ▪ Location: Northern Kenya ▪ Age: ~4.5 - 3.9 mya ▪ Ape-like features ▪ Slight canine/premolar honing complex ▪ Hominin-like features ▪ Bipedal modifications in lower limbs ▪ Molars with thick enamel ▪ Potential ancestors for later Australopithecines (e.g., A. afarensis)
Homo neanderthalensis ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available)
▪ First discovered in Neander Valley (Germany) in 1856 ▪ Age: ~130 - 30 kya ▪ Note: Different time ranges across texts and resources ▪ Location: Europe and Western Asia ▪ Large Brain: ~1200 - 1740 cc ▪ Mean:1520 cc ▪ Larger than modern humans (~1400 cc)! ▪ Distinctive cranial and post-cranial features ▪ Broad knowledge about Neandertals ▪ Lived in Europe; extensively studied by paleoanthropologists ▪ DNA has been extracted ▪ Large brain size (mean: ~1520 cc) ▪ Long skull ("football" shaped) ▪ Prominent, arching brow ridges ▪ Mid-facial prognathism ▪ Wide nasal aperture ▪ Retromolar gap: Behind 3rd molar ▪ Occipital bun ▪ No chin
Darwinian (genetic) adaptations
▪ Genetic or Darwinian Adaptation: Reflects natural selection; developed over many generations ▪ Measuredthroughdifferentialfertilityand mortality ▪ Among humans, genetic change expected to be adaptation of last resort ▪ Takes a long time ▪ Reduces long-term flexibility ▪ Genetic adaptation expected when: ▪ Environmentalstressorsarepresentovera long time period ▪ Stressorscan'tbebufferedusingothermeans (e.g., culture or behavior)
What are the differences in genetic diversity among chimpanzees and humans? Which group shows higher or lower genetic variability?
▪ Genetically, humans are extremely homogeneous ▪ Humans differ, on average, at only one out of every 500-1000 nucleotides ▪ Humans show low levels of genetic variability relative to common chimpanzees (Pan troglodytes)
What are "geographic clines", and what do they demonstrate about human genetic and phenotypic variation?
▪ Human genetic diversity forms geographic clines ▪ Continuum of traits across geographical space; no major geneticdiscontinuities between different continents or "races" ▪ Extensive genetic sharing across continents the rule, not the exception
Johann Blumenbach
▪ Johann Blumenbach (1752-1840), the so- called "father of physical anthropology" ▪ Defined the "classic" races in 1795 ▪ Caucasian ▪ Mongolian ▪ Ethiopian ▪ American ▪ Malay ▪ Field moves towards focus on the skull, era of measurement, and explicit hierarchy/ranking
What types of studies did Richard Lewontin conduct to understand patterns of genetic variation among humans? What were the key findings from Lewontin's studies?
▪ Most Variation Within Populations ▪Lewontin,1972:Analyzedallelefrequencydifferencesofclassical genetic markers (e.g., blood groups) ▪NumerousotherstudiesusingclassicalmarkersandDNA sequencing (e.g., insertion/deletions and microsatellites) ▪ 10% of variation between "races" ▪ 5% of variation between populations within regions ▪ 85% of variation within populations!!
What are the important features associated with the "Turkana Boy" fossil (e.g., age, location, brain and body size, significance)?
▪ Most complete H. erectus skeleton ▪ Age: ~1.65 mya ▪ Location: W. Turkana, Kenya, E. Africa ▪ Brain size: ~900 cc ▪ ~8 years old ▪ ~5'3" tall and ~100 lbs. ▪ Similar stature to modern humans ▪ Long legs
What were the key events leading to the demise of the race concept?
▪ New understanding of evolutionary theory brought about by the modern evolutionary synthesis ▪ Recognition of the extent of human plasticity in response to environmental factors ▪ Environment affects the expression of most phenotypic traits ▪ New understanding of variation within and between populations in different phenotypic traits ▪ Social climate of the time and rejection of scientific racism
How is skin color distributed geographically? What is Gloger's rule? What selective pressure from the environment has affected skin color distribution throughout the world?
▪ Skin color not randomly distributed geographically ▪ Patterned by latitude ▪ Latitudinal correlation with skin color known as Gloger's rule ▪ Suggests selection to environmental factors ▪ Latitude as proxy (e.g., solar radiation)
Race as a worldview and social race
▪ Socialrace:Reflectsagroupperceived and defined in a social context by a particular culture ▪ Publicperceptionisthatracesare discrete, permanent, and relatively homogenous ▪ Variation culturally in how race is classified ▪ US approach is not the only system ▪ Race as a worldview ▪ A culturally structured way of perceiving and interpreting reality
What are some of the major health disparities between racially-defined groups?
▪ Substantial inequalities between racially defined groups for all major causes of morbidity & mortality ▪ Cardiovascular disease and diabetes ▪ Cancer ▪ Infections ▪ Low birth weight and preterm delivery ▪ Burden of poor health especially high in African Americans ▪ Age-adjusted death rate for African Americans >30% higher than US whites ▪ Race is often used uncritically in biomedical science and public health ▪ Assumptions that racial differences explained by genetic factors
What does this scenario indicate about the social behavior of early hominins?
Evidence indicates that others may have cared for Turkana Boy during his illness, which shows cooperative behavior among early hominins.
The Laetoli footprints were likely made by which hominin? a) Homo erectus b) Australopithecus afarensis c) Paranthropus genus d) Australopithecus africanus e) Homo habilis
Australopithecus afarensis
The best- known early hominin is: a) Australopithecus afarensis b) Australopithecus anamensis c) Orrorin tugenensis d) Ardipithecus ramidus e) Sahelanthropus tchadensis
Australopithecus afarensis
Based on fossil evidence, what is a possible scenario for the death of Turkana Boy?
Based on fossil evidence, Turkana Boy may have died from an abscess and resultant infection in his lower jaw.
According to Brunet, was Sahelanthropus tchadensis bipedal?
Brunet suggests that Sahelanthropus tchadensis was bipedal based on the anterior position of the foramen magnum.
Early hominins primarily evolved in which area of the world: a) East Africa b) West Africa c) North America d) Southeast Asia e) Southwestern Africa
East Africa
Cranial/sagittal crest
Elevated bone along the midline of the cranium - Attachment site for muscles
From what geographic location do we have strong evidence that modern humans and Neandertals overlapped in both space and time? a) West Africa b) South Africa c) East Asia d) Europe e) Near East
Europe
In what type of climate and environment did "Selam" and Lucy live? What evidence has been found to support these findings?
In contrast, "Selam" and Lucy lived in a mosaic of different ecosystems in Africa (e.g., grassy plains, scattered woodlands) because the environment gradually dried out and rainforests began to shrink approximately 3 - 4 million years ago. Scientists have supported these findings using fossil evidence from animals who lived in the area (e.g. antelopes) during that time.
What are the key morphological determinants of the genus Homo?
Large brain relative to body size - 40% increase among early Homo compared to Australopithecines - Also,smallerteethandlargerbodysize
What are some of the major changes associated with Homo erectus (e.g., body and brain size, cranial features, diet and lifeways, tool-use)?
Low forehead, Long and low braincase, Less facial prognathism than H. habilis, Relatively larger brain compared to H. habilis, no chin, Large and continuous supraorbital torus, Sagittal Keel, Very thick cranial bones, Cranium broadest at base (below ear openings), Dental reduction (smaller teeth)
Which of the following statements is true about the Recent African Origin/"Out of Africa" model? a) Modern humans evolved in Africa and Europe at the same time b) Pre-modern humans first evolved into modern Homo sapiens in Russia c) Modern humans evolved in Asia and Europe at the same time d) Modern humans evolved in Africa and then left Africa and globally dispersed e) None of these answers are correct
Modern humans evolved in Africa and then left Africa and globally dispersed
According to the paleoanthropologist Rick Potts, what was the primary catalyst for human evolution?
Rick Potts suggests that the primary catalyst for human evolution was rapid climate instability. His hypothesis is based on observations of different rock layers, suggesting dramatic environmental change.
What evidence has contributed to these hypotheses?
Scientists are also using diatoms (unicellular organisms that live in water) to determine how lake sizes have changed over time, demonstrating fluctuations between wet and dry environments. Other scientists are examining layers of deep sea sentiment to determine environmental fluctuations.
Which area of the world are scientists searching for fossil evidence of human evolution?
Scientists are searching for fossil evidence of human evolution in the Afar region of NE Ethiopia, which is a part of the Great Rift Valley.
Dental arcade
Shape made by the rows of teeth in the upper jaw: parabolic shape= human parallel U-shaped= chimpanzee
How were these tools used?
Some researchers suggest that the first stone tools were used to break open the long bones of animals in order to extract marrow, suggesting that meat may have become an important part of the diet of Homo habilis.
What are some key morphological differences between Homo habilis and Australopithecus?
There are key morphological differences between Homo habilis and Australopithecus in the skull. For example, Homo habilis had a larger cranial capacity, an elevated forehead, and expansion behind the orbits (i.e., reduced postorbital constriction). Conversely, Australopithecus had a smaller cranial capacity, no forehead, and constriction behind the orbits.
Based on this evidence, what do we know about the brain development of "Selam"?
These findings indicate that the brain of "Selam" was growing slower compared to the brains of chimpanzees.
Based on current evidence, why did Homo erectus leave Africa?
They followed the migration of animals, their food source.
How was this species different from earlier hominin groups (e.g., Australopithecus)?
This hominin species was different from earlier hominin groups based on its larger brain and body size.
Why do paleoanthropologists have a broad knowledge of Neandertals?
This species primarily developed in Europe and were at easy access for paleoanthropologist to study when the field was first developing starting in Europe.
European perspective and colonialism
▪ European perspective shaped by exploration and colonialism ▪ Contact with unfamiliar people ▪ Material remains, including monuments and antiquities
Australopithecus afarensis ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available) ▪ The ways in which the fossil is more ape-like or human-like
• Best-knownearlyhominin - Fossils of over 70 individuals from 6 different sites in E. Africa • Age:~3.9-3.0mya • Cranialfeatures - Small brain (350 - 500 cm3) - Prognathic face - Anteriorly placed foramen magnum Dental Features - Canine reduced but still large - Large molars with thick enamel - Parallel dental arcade • Habitual Bipedalism - Pelvic morphology - Lower limb proportions intermediate between ape and human • ArborealAdaptations - Curved, long phalanges - Long arms • PronouncedSexualDimorphism - Weight: ~45 kg vs. ~29 kg - Height: 150 cm vs. 110 cm - Canine size - Debated among paleoanthropologists
Paranthropus aethiopicus ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available) ▪ The ways in which the fossil is more ape-like or human-like
• Earliest robust form • Age: ~2.5 - 2.3 mya • Location: Ethiopia & Kenya, E. Africa • Cranium: • Small brain size (~410 cc) • Dish-shaped face and pronounced sagittal crest • Flared zygomatic arches • Extreme facial prognathism • Very large molar teeth • Limited postcranium evidence • Potential ancestor of other Paranthropus forms
Based on current evidence, Homo heidelbergensis from Africa and Europe were the likely ancestors to which hominin groups?
• European H. heidelbergensis: The likely ancestor of Neandertals • African H. heidelbergensis: The likely ancestor of modern humans
Homo sapiens ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available)
• Evolved in Africa ~200,000 years ago and show evidence of modern human anatomy • Average cranial capacity: ~1350 cc • Small teeth • Small face • Canine fossa: Depression on the surface of maxillary bone caused by the socket of the canine tooth • Well-defined chin • Rounded skull with vertical forehead • Reduced supraorbital torus
How are Acheulean tools made, and how are they used? When did they first appear in the fossil record?
• First appear in Africa ~1.6 - 1.4 mya • Found mostly in Africa and western and central Eurasia; few locations in east Asia • BifacialFlaking:Flakedonbothsides • Strong and sharp hand axes • Preconceived shape; required a "mental template" • Carried from place to place • Used to process meat; also, possibly wood and bones
Multiregional Evolution/Continuity
• Homo Erectus left Africa and then evolved into modern humans in several different locations throughout the world • All populations experienced similar patterns of change (i.e., continuity) due to gene flow and common modes of adaptation • Differences in genes and morphology due to adaptations to local environments • Modern humans are the most recent morphological form of Homo sapiens, which have been around for ~2 million years • For this to be true: • Homo erectus left Africa 2million years ago • All modern humans came from this group • Geneflowoccurredbetweenregions • Natural selection since the original dispersal is responsible for regional phenotypic variation • Evidence: • Some regional continuity between Homo erectus, Archaic Homo sapiens, and Anatomically modern Homo sapiens in the fossil record • However,substantial disagreement
What is a genotype, and what is a phenotype? How do humans differ in genotype and phenotype?
• Humans are very similar in genotype - Genetic make-up of an organism • However, humans are significantly different in phenotype - Physical manifestation of the genotype (i.e., observable characteristics)
What are some examples of Neandertal culture and behavior?
• Hunters -Able to hunt large game (e.g., bison, deer) in coordinated groups using long spears -Evidence of healed injuries similar to rodeo athletes -Tooth wear from processing hides -Provided assistance to injured individuals? • Buried Dead - Deliberately positioned in graves - Someevidenceof"gravegoods" • Symbols and Ornaments -Necklaces (e.g., shells) -Bodypigments
Ardipithecus ramidus ▪Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available) ▪ The ways in which the fossil is more ape-like or human-like ▪ In what type of ecology did this hominin live?
• Location:Central Kenya • Age: ~6 mya • Ape or hominin? • Hominin status • Femoral angle (valgus) • Long femoral neck length • Thick molar enamel • Ape status • Partial honing canine • Curved hand bones
Sahelanthropus tchadensis ▪Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available) ▪ The ways in which the fossil is more ape-like or human-like
• Location:Northern Chad, Central Africa • Age: ~6-7mya • Odd mixture of features: More ape- or hominin-like? • Intermediate foramen magnum • Suggestive of bipedalism • Small brain (<400 cubic centimeters) • Large brow ridges and cranial crests • Small face
Homo rudolfensis ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available)
• Questionable classification - Little postcranial material - Homohabilis,Paranthropus? • Age: ~2.4 - 1.6 mya • Location: East Africa • Encephalization: Brain size of ~700 cc • Body Size: Within range of modern humans (~5 feet tall) • Teeth: Smaller premolar and molars • Pelvic Girdle: Modifications similar to later Homo
What are some of the general characteristics associated with the Paranthropus genus (e.g., dietary adaptations, dental features, body and brain size)?
• Robust Dietary Adaptations • Prominent sagittal crest • Attachment site for chewing muscles • Crushing and grinding molars (megadontia) • Molars larger than expected for body size • Process high quantities of low quality foods during food stress (e.g., seeds, grasses) -flaring zygomatic
Eugenics movement
▪ Eugenics: The philosophy of "race improvement"; idea that controlled selective breeding can improve the human species ▪ Francis Galton (1822-1911) ▪ Eugenics movement in the Europe and the US ▪ Sterilization and anti-immigrant movement ▪ Nazi pseudoscience and idea of racial purity
Homo heidelbergensis ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available)
• Transitional species between H. erectus and later hominins (e.g., modern humans and Neandertals) - Pronounced supraorbital torus, thick cranial bones, and no chin, yet larger brains and reduced dentition • Age: ~600 - 200 kya • Location: Africa, Europe, and Asia (China) • Brain Size: ~1100 - 1450 cc • Body Size: Similar to modern human range • Compared to H. erectus • Supraorbitaltori:Less prominent and separated (arching), yet still large • Sagittal keel and occipital torus: Less pronounced • Robusticity:Decreased,yet some thickness of cranial bones • Brainsize:Largerandvertical sides • Some within modern human ranges
What was the geographical distribution of archaic Homo sapiens/Middle Pleistocene hominins?
• Widely distributed: Africa, Asia, and Europe • For the first time, Europe becomes more densely occupied (e.g., France, Spain, Germany, Hungary, Italy) • Replacing, or coexisting, with earlier hominins (e.g., Homo erectus) in previously exploited habitats; range was not vastly extended
What are some of the key morphological differences between archaic and anatomically modern humans?
•Modern • Small brow ridge • Flat face • Flat, small cheekbones • Small teeth • Archaic • Large brow ridge • Projecting face • Large, wide cheekbones • Larger teeth
What is an adaptation? What is homeostasis? What are stressors?
▪ "Adaptation": Refers to changes by which an organism surmounts to challenges in life ▪ Measuredintermsoffitness:Differentialsurvivorship(mortality) and differential reproduction (fertility) ▪ Homeostasis:Abilitytomaintainandrestoreastableinternal physiological environment within tolerable limits ▪ Stressor (Stress): Factor that disrupts normal functioning and interferes with homeostasis ▪ Physical (cold, heat, hypoxia, etc.) or Psychological ▪ Ability to maintain homeostasis as measure of adaptive success
"Great Chain of Being"
▪ "Great Chain of Being": A universal hierarchical ladder ▪ Implied or explicit rank order of superiority from European to Asian to American to African ▪ Reflected worldview of Europeans at the time
How is "race" a sociocultural phenomenon?
▪ "Race exists as a sociocultural phenomenon that has force in people's lives—one with biological consequences" (Gravlee 2009) ▪ Health disparities as a window onto race
Based on recent evidence, how is genetic variation distributed among modern humans (e.g., between "races", between populations, within populations)?
▪ 10% of variation between "races" ▪ 5% of variation between populations within regions ▪ 85% of variation within populations!!
Homo Erectus ▪ Age range ▪ Geographical location and distribution ▪ Cranial capacity (if available) ▪ Cranial and dental characteristics (if available) ▪ Postcranial characteristics (if available)
▪ Age: 1.8 mya - 143 kya ▪ Note: Fossils from Java originally suggested H. erectus lived to 50 kya; these fossil dates have recently changed to 546 - 143 kya ▪ Locations: Africa, Asia, and Central/Western Eurasia ▪ Major Changes - A "Grade" Shift: ▪ Geographic distribution ▪ Larger body size (5.3 - 5.9 ft.) and proportions (shorter arms) ▪ Larger brain size (727-1251 cc) ▪ Facial and dental reduction ▪ Diet and lifeways ("hunter-gatherers") ▪ Stone tool technology (Acheulean) • Pronounced supraorbital torus • Occipital/nuchal torus - Pronounced ridge on rear- most occipital bone • Sagittal keel/ridge - Raised area where parietals meet on top of cranium • Thick cranial vault • Widest point at the base of the skull • Shovel-shaped incisors
What type of tools did modern humans use? What are the advantages of these tools?
▪ Blade industry ▪ Made from stone flakes ▪ Flakes are twice as long as they are wide ▪ Wood, ivory, and bone carved to produce small tools (e.g., fishhooks, needles) ▪ Atlatl (i.e., spear-thrower) ▪ Able to better exploit surrounding environment (e.g., collect fish, increased food processing) ▪ Regional variation and "style"
Carolus Linnaeus
▪ Carolus Linnaeus (1758) ▪ First systematic attempt at human classification ▪ Assigned varieties or "races" ▪ Homo sapiens afer (Africans) ▪ H.s. americanus (American Indians) ▪ H.s. asiaticus (Asians) ▪ H.s. europaeus (Europeans) ▪ H.s. ferus ("wild men") & H.s. montrous ▪ Most early (18th & 19th century) classifications used some type of ranking system
What are the disadvantages of light skin in high sunlight environments? What are the advantages of dark skin in high sunlight environments? What are the disadvantages of dark skin in low sunlight environments? What are the advantages of light skin in low sunlight environments?
▪ Disadvantages of light skin ▪ Increasedlikelihoodofsunburn from UV wavelength light (UV-A & UV-B) ▪ Increased skin cancer risk ▪ Susceptibletofolatedepletion ▪ Abnormally low levels of this essential B vitamin with light treatment ▪ Essential for DNA synthesis (e.g., spermatogenesis) ▪ Neural tube defects (e.g., spina bifida) ▪ Likely consequences for reproductive success ▪ Advantages of dark skin ▪ Protectsagainstsunburn ▪ Passive: Absorbs, scatters, and reflects UV light ▪ Active: Neutralizes free radicals in skin from UV radiation damage ▪ Dark pigmentation: Sun protection factor (SPF) of ~10 ▪ Moderately pigmented people (e.g., circum-Mediterranean): SPF of ~2.5 ▪ Protectsagainstfolate depletion ▪ Disadvantages of dark skin ▪ HypovitaminosisD ▪ Vitamin D critical for calcium absorption, metabolism, and immune function ▪ Vitamin D sources ▪ SynthesisofVitaminD3from UV-B exposure ▪ Diet (Vitamin D2) ▪ Higher risk of rickets ▪ Increasedsensitivityto frostbite ▪ But, cultural adaptations ▪ Diet, clothing, housing, etc. ▪ Advantages of light skin ▪ IncreasedVitaminDsynthesisin low light environment ▪ Lesssusceptibletofrostbite ▪ Cultural factors as adaptations (diet)
What is evolutionary convergence, and how does this concept affect our understanding of racial classification systems?
▪ Distantly related populations are similar for certain traits if they evolved under the same selective pressure (but not indicative of genetic relatedness) ▪ Skin color phenotypes in sub-Saharan Africa, southern India, Australia, and Melanesia cluster together ▪ "Pygmy" groups in West Africa and Southeast Asia convergent evolution in morphology (e.g., small body size)
What are some examples of art, symbolism, portable art, personal ornamentation, and ritual used by modern humans?
▪ Elaborate cave paintings (by ~40,000 years ago) ▪ Example: Lascaux Caves in France (date to ~17,000 years ago) ▪ Painted onto the walls using mineral pigments -portable art and personal ornaments
What are some of the general characteristics associated with the Australopithecus genus (e.g., locomotion pattern, body and brain size, dental features, habitat)?
▪ Thrived in Africa for over 2 million years ▪ Habitual bipeds ▪ Small-bodied (3.5 - 5 feet tall) ▪ Slightly larger brains (yet still small) ▪ Large molars with thick enamel ▪ Small canines and reduced honing complex ▪ Limited tools and culture ▪ Lived in various habitats in east, central and south Africa (e.g., open woodlands, grasslands) • Robust (South Africa and East Africa), Paranthropus robustus, boisei, aethiopicus • Dispersal into South Africa • Diversification into gracile and robust forms • Gracile (South Africa only), Australopithecus africanus
What are the different modes of human adaptation?
▪ Types of Adaptation ▪ Cultural/Behavioral ▪ Tools, technology, and language ▪ Subsistence strategy & diet ▪ Medicine ▪ Aspects of culture can be adaptive and allow survival while others can create new stressors (e.g., pollution) ▪ Biological ▪ Biologically, humans adapt to their environments through: Darwinian (genetic) adaptations, developmental plasticity/acclimatization, and acclimatization ▪ Human emphasis on multiple simultaneous adaptive pathways
What evidence suggests that humans are not still evolving? What evidence suggests that humans are still evolving?
▪ Until recently, the answer was "No" ▪ Humans beyond evolution (reached "peak") ▪ Food production & population expansion ▪ Technology ▪ Modern medicine & disease eradication ▪ Humans have not evolved into multiple species ▪ Remember: Evolution is not just selection but includes multiple forces ▪ Mutation, gene flow, genetic drift, and natural selection ▪ Revolutionary advances in genomics have provided evidence of recent human evolution ▪ Human Genome Project ▪ Yes—Evidence for recent and ongoing evolution since beginning of food production ▪ Genetic evidence of selection (e.g., malaria resistance, lactose tolerance, skin color, etc.) ▪ ~7% of human genes have undergone recent evolution ▪ Newest genes are regional ▪ Recent evidence of genes that evolution has strongly favored ▪ Positive selection: New, advantageous genetic variants sweep a population
When did the Upper Paleolithic cultural period begin? What is the significance of this cultural period?
▪ Upper Paleolithic Cultural Period ▪ Started ~40 kya ▪ Advent of modern humanity ▪ New complexity in tools, hunting and foraging behavior, and symbolic expression
Understanding variation within and between populations in phenotypic traits
▪ Variation typically continuous in most traits used to study race (e.g., height, weight, skin color, cranial shape) ▪ Polygenic traits ▪ Different traits lead to different groupings (Nonconcordance) ▪ Why a focus on skin color, head shape, hair color, & other commonly used racial traits? ▪ Why not lactose tolerance, sickle cell trait, height, or something else? ▪ Thus, categorization of human races is subjective
What is Allen's rule? What does it demonstrate about the relationship between body appendages and temperature?
▪Allen's Rule: Appendages (e.g., arms & legs) within a species shorter at lower temperatures, longer at higher temperatures ▪Body shape and body mass to surface area ratios ▪Shorter appendages: Relatively lower surface area and greater heat retention in cold climates ▪In warm climates, longer appendages with relatively higher surface area leads to greater heat dissipation
What is Bergmann's rule? What does it demonstrate about the relationship between body size and temperature?
▪Bergmann's Rule: Body size within a species larger at lower temperatures, smaller at higher temperatures ▪Relationship of body mass to surface area ▪Higher body mass: Relatively lower surface area and greater heat retention in cold climates ▪In warm climates, smaller body size leads to relatively higher surface area and greater heat dissipation
What are some examples of Bergmann's and Allen's rule in humans (e.g., body weight, relative sitting height)?
▪First systematically documented in humans by Derek Roberts ▪Body Weight: Negatively correlated with mean annual temperature (Bergmann's Rule) ▪Lower body weight at higher temperatures ▪Relative Sitting Height: Negatively correlated with mean annual temperature (Allen's Rule) ▪Longer trunk at lower temperatures