Exam 3 Study Guide Fall 2024 PDF

**PRIMATE SOCIAL BEHAVIOR** Sexual Selection Intersexual selection (Female Choice) Intrasexual selection (Male/Male Competition) Why do primate females do the choosing and males do the competing for access to **INTRODUCTION TO PALEONTOLOGY** *In this section, you learned the basic principles o...

**PRIMATE SOCIAL BEHAVIOR** Sexual Selection Intersexual selection (Female Choice) Intrasexual selection (Male/Male Competition) Why do primate females do the choosing and males do the competing for access to **INTRODUCTION TO PALEONTOLOGY** *In this section, you learned the basic principles of the study of fossils.* Taphonomy Geological Principle of Superposition Fossil Figuring out the age of a fossil: What's the difference between "relative dating" and "absolute dating?" Radioisotopic dating What is a half-life? How is the radioisotopic decay of isotopes used to "date" fossils? If I tell you that the half-life of ~14~C is 5730 and that a bone found in cave has only ¼ of the original ~14~C remaining, how old is the bone? How do we use changes in magnetic polarity to check the absolute dates assigned to fossils? Depositional Environments: Fluvial Lacustrine Caves Karst systems *osmas* Where is it found? What is its geological age (i.e., in which epoch did it live)? **OVERVIEW OF PRIMATE EVOLUTION AND DEEP TIME** Cenozoic Era: Know the Epochs that make up the Cenozoic and their ages Paleocene (65 -- 54 million years ago) Eocene (54 -- 34 mya) Oligocene (34 -- 23 mya) Miocene (23 -- 5.5 mya) Pliocene (5.5 -- 1.8 mya) Pleistocene (1.8 mya -- 10,000 years ago) Holocene (10k -- today) Radiations of Fossil Primates Adapids In what epoch did the radiation primarily occur? Body size: Diet: Generally speaking, how did the adapid niche differ from the omomyid niche? Omoyids In what epoch did the radiation primarily occur? Body size: Diet: Locomotion: Generally speaking, how did the omomyid niche differ from the adapid niche? In what ways are omomyids considered to be "tarsier like." Oligocene Platyrrhines In which epoch do we observe the earliest platyrrhines in S. America? Eocene Anthropoids Eocene Anthropoids *Eosimias* Where is it found? What is its geological age (i.e., in which epoch did it live)? Oligocene Anthropoids of Africa The Fayum Where is the Fayum geographically? *Aegyptopithecus* and other early catarrhines Locomotion of *Aegyptopithecus* **HOW TO IDENTIFY A HOMININ** Miocene Hominoids In which epoch is hominoid taxonomic diversity highest? During the Miocene, where are hominoid found geographically? When did hominoid diversity decline? Describe the locomotor diversity of Miocene hominoids. Describe the dietary diversity of Miocene hominoids. Describe the body size diversity of Miocene hominoids. What were Africa and Asian primate communities like in the Miocene? What about today? What are two factors that are hypothesized to explain the loss of hominoid diversity in the Late Miocene? How do humans differ from other apes? We are bipedal. What are the morphological correlates of bipedalism? There are a lot, know them. Foramen magnum position. How does the foramen magnum position influence the location of the spine in relation to the cranium? Curvature of the spine. Contrast a quadruped and a biped. 1 curve in a quadruped 3 curves in a biped Cervical lordosis Thoracic kyphosis Lumbar lordosis In what direction does a lordotic curve bend? Why does the biped have these curves? Think about it in terms of balance. Without these curves, which way would a biped tend to fall over? Why do chimps stand and walk bipedally with a bent hip, bent knee posture? ^Pelvis^ Shape, size, and orientation of iliac blades in bipeds and quadrupeds Be able to describe the pelvis of a biped and quadruped using anatomical directional terms. Function of the gluteus medius and minimus in bipeds and quadrupeds. How does changing the shape of the ilium change the function of the gluteal muscles? In a biped, the gluteal muscles prevent us from falling in which direction relative to the unsupported foot? ^Knee^ Valgus vs. Straight knee. Presence of a bicondylar angle = valgus knee How does the valgus angle reflect the position of the knees in relation to the midline of the body? Why is a valgus knee advantageous for a biped? Think about balancing on one foot. Foot shape/function Big toe (hallux). In line with other toes or divergent? How does it differ between a biped and quadruped in terms of its anatomy and function? How do humans "toe-off?" What is a divergent big toe used for? Medial longitudinal arch We have small canines. We have nondimorphic canines (male canines are only slightly larger than female canines). We have nonhoning canines. What is the canine honing complex? What is the sectorial/honing premolar? What does it do? Which three teeth comprise the canine honing complex in extant apes? We have big brains. We have a broad dietary niche that includes meat protein. We acquire and process a lot of our food using tools. We process food extensively outside of our mouth (extraorally) Why would the earliest hominin have looked very ape-like? Think about it in terms of the mode of speciation that would have occurred and what actually happens during a speciation event. What is allopatric speciation? What role does gene flow play in speciation? **MIOCENE AND PLIOCENE HUMAN EVOLUTION** Be able to locate on a map: Kenya Ethiopia South Africa Tanzania African Rift Valley. What is the African Rift Valley? What's going on geologically? *Ardipithecus ramidus* Geographical area of discovery Geological age The person(s) who discovered it What the name means Why it may be a hominin Why it may not be a hominin. Focus on the foot, the big toe (hallux) especially ***AUSTRALOPITHECUS* AND *PARANTHROPUS*** Pliocene Hominins *Australopithecus afarensis* and *A. africanus* Geographical area of discovery Geological age What their names mean Cranial morphology Brain size Canine Size: Are the canines sexually dimorphic? Canine function: Are the canines honed like in extant apes? Postcanine Tooth Size What is postcanine megadontia? Foramen Magnum position Facial prognathism/orthognathism Cranial Cresting Postcranial morphology Pelvis shape Knee shape Arch presence/absence Hallux morphology What does the Laetoli footprint trail tell us about *A. afarensis* locomotion? *Paranthropus robustus* and *P. boisei* Geographical areas of discovery Geological ages What their names mean Cranial morphology Brain size Canine Size: Tiny canines Incisor Size: Tiny incisors Postcanine Tooth Size Postcanine hypermegadontia Premolar molarization. Foramen Magnum position Facial prognathism/orthognathism Flaring Zygomatics. Why are the zygomatics so flared in *Paranthropus*? Forwardly placed zygomatics and "dished" midface. Cranial Cresting What muscle of mastication attaches to the sagittal crest? What muscle of mastication attaches to the broad zygomatic bones? **\*\*\*\*\*Which came first during human evolution: obligate terrestrial bipedalism, reduced nonhoning canines, large brains, or stone tools? Assume that *Ar. ramidus* is a good guide for what hominins that predate *Australopithecus* would have looked like.\*\*\*\*** Iconic fossils: Though I won't test you specifically on their names, it may be helpful to learn these iconic fossils and wnow which species they belong to and why they are important Lucy Selam Taung Child Laetoli footprint trail Ardi (the *Ar. ramidus* partial skeleton) Twiggy **EVOLUTION OF HOMININ DIETS**/**ORIGIN OF GENUS *HOMO*** Stone tools: know the basic technological aspects Core Hammerstone Flake Oldowan Stone Tool Industry The Killer Ape Hypothesis Who did Dart think was the killer ape? Osteodontokeratic Tool Culture What is it? If *A. africanus* didn't collect the bones in the caves, then who/what did? What is the evidence that Oldowan stone tools were used to acquire meat? What are cutmarks on bones? What evidence is there that marrow was extracted from bones using stone tools? *Homo habilis* Geographical area of discovery Geological age What the name means Cranial morphology Brain size Canine Size Postcanine Tooth Size Foramen Magnum position Facial prognathism/orthognathism Cranial Cresting Postcranial morphology Hand morphology Foot morphology Which hominin is the likely stone tool maker at Olduvai? Which plants follow a C3 photosynthetic pathway? Which plants follow a C4 photosynthetic pathway? What is the general trend for hominin diets in terms of the use of the C3 and C4 vegetation? Which hominin has a nearly pure C4 signal? ***Homo erectus*** *Homo erectus plays a prominent role in human evolution for a number of reasons. Compared to earlier hominins, including Homo habilis, Homo erectus looks and behaves decidedly more like humans. Almost all paleoanthropologists hypothesize that Homo erectus was directly ancestral to us, though there were several intermediates and offshoots before you get to us. Below, I've tried to highlight the major points of importance for Homo erectus.* What is the savannah hypothesis for the origins of bipedalism? Why is the savannah hypothesis wrong when it comes to explaining the ***origins*** of bipedalism? What environments were occupied by the earliest bipeds (e.g., *Ardipithecus* and *Australopithecus*)? Why might adaptations to savannah life explain the anatomy and behavior of *Homo erectus?* In addition to *H. erectus*, what other hominin lineage adapted to life on the savannah? What evidence do we have that this lineage exploited savannah habitats? *Homo erectus* Where are fossils of *Homo erectus* found? When does *H. erectus* appear in the fossil record? What is the age of the oldest fossils attributed to *H. erectus* that are found outside of Africa? Where are these fossils found? Is *H. erectus* the geologically oldest hominin that we find outside of Africa? What tool technology is associated with the first *H. erectus* out of Africa? What was the diet of *H. erectus*? How did its diet differ from earlier hominins? If *H. erectus* was a hunter, how might it have killed animals? *H. erectus* gave rise to numerous populations of *Homo* throughout the Old World. Why might allopatric speciation have occurred as a result of this? What role does gene flow play in the process of allopatric speciation? When/where does the Achuelean appear? What is a hand axe? Is it a core tool or a flake tool? **THE "Muddle in the Middle" AND NEANDERTALS** *Neandertals figure prominently in the story of human evolution, mostly because, in comparison to all other hominins that have ever lived, they are very similar to us. But, at the same time, they just seem a bit different. From an anatomical standpoint, they are quite distinct from modern humans. They are distinct in ways that are not primitive; that is, they have a package of unique features not seen in other hominins. From that standpoint, it would seem that they are not our ancestors and are, rather,* *an extinct side branch. From a behavioral standpoint, though, they seem eerily similar to modern humans. To others, they fail to make the behavioral modernity grade and instead appear to be an overly-specialized, cold-adapted, highly-carnivorous, behaviorally-inflexible, evolutionary dead end.* Where is Sima de los Huesos? Why does the Sima sample appear to be an intentional collection of individuals? What's the Neandertal time range? Where are Neandertals found geographically? What is an autapomorphy? Know the following Neandertal autapomorphies and what each autapomorphy looks like anatomically: Occipital bun Receding Zygomatics Retromolar gap Taurodont molars Large nasal opening Beveled incisor wear (not truly an anatomical autapomorphy, but probably reflective of a behavioral autapomorphy). Why are Neandertal autapomorphies used to argue against their being ancestral to modern humans? What is the Neandertal body shape like in comparison to most modern humans? What might this body shape be an adaptation to? What are Allen and Bergmann's Rules? Would a Neandertal have a higher or lower surface area to volume ratio than say a modern human living at the equator? What is the traditional view of the Neandertal dietary niche? What recent evidence challenges this view? The pattern of skeletal trauma in Neandertals is most similar to which group of modern humans? What evidence is there that suggests that Neandertals were capable of spoken language? What is the Mousterian stone tool industry? What is the Levallois flaking technique? Which hominin species are associated with the Mousterian? **ORIGIN OF *Homo sapiens*** *In this section, I went over the origin of our species, Homo sapiens. We reviewed the fossil record to locate the oldest anatomically "modern" members of our species. We also reviewed the evidence of behavioral "modernity" as it's preserved in the archaeological record.* Know the following autapomorphies of anatomically modern *Homo sapiens*: Chin Vertical forehead Rounded Cranial Vault in lateral view When do the first anatomically modern *Homo sapiens* appear in the fossil record? Where do they appear? Where do we find the oldest evidence for anatomically modern *Homo sapiens* outside of Africa? How old are these fossils? How do the oldest *Homo sapiens* fossils compare in age to the Neandertals in Europe and western Asia? For how long were Neandertals and anatomically modern *Homo sapiens* sympatric in Europe? What is mtDNA? Where is it found in the cell? What's the pattern of inheritance for mtDNA? Where/when did mitochondrial Eve live? Why is mtDNA relevant to the debate over modern human origins? Does Neandertal mtDNA fall within the range of variation observed for human mtDNA lineages? When is the estimated divergence between the two sets of mtDNA lineages? Where/when did Y\-\--chromosome Steve/Adam live? Is overall human genetic diversity high or low compared to other species? How much of the modern nonAfrican human genome was likely contributed by Neandertals? Where do we find the earliest evidence for symbolism in a human population? How old is this symbolic behavior? What's going on with ochre at Blombos? How old is the Blombos cave? What's the oldest evidence for jewelry? Where is this evidence found? What's the oldest portable art in Europe? **MODERN HUMAN VARIATION AND RACE** *The basic gist of this section is that phenotypic and genetic variation among populations of modern humans do not conform to biological definitions of "race." As we often apply the race concept to groups of people, we create artificial groupings that do not reflect underlying genetic or phenotypic variation. Moreover, there is no evidence for ranking groups of people hierarchically or considering some "races" "more evolved" or "less evolved" than others. What in the world does "less evolved" mean anyway?* What are historical classifications? What are descriptive classifications? What are the biological criteria for a population to be considered a race? What evidence exists to show that human populations are not genetically isolated from one another? What are clines? What evolutionary mechanisms produce clinal variation among modern human populations? What percent of human genetic variation exists **between** populations? What percent of human genetic variation exists **within** populations and is shared by all human populations? When did the mutation occur in the SLC24A5 gene to produce exceptionally light skin in most Europeans? Why is dark skin adaptive in equatorial regions? Why is light skin adaptive in regions away from the equator?