May 1st Friday Morning 8:00 AMFinal Exam Review Chapter 8 : Foundations of the primate and hominin fossil recordFossil PrimatesGeologic time (chp 5) What are the epochs of the Cenozoic—and significant events in primate evolution for each Paleocene (65-56 MYA)- A major radiation of archaic primates, plesiadapiforms occurred 65-52 Mya- These creatures are known from fossils found in American west (Montana, Wyoming)- jaws size of dime- Plesiadapiforms are the earliest known primates Eocene (55-33 MYA)- Primates of modern aspect- “POMA” euprimates- adapids and omomyidso found in N. America and Europe - extended to Asia and Africa (widely distributed)o Mostly were extinct by the end of the Eoceneo Potential ancestors of the lemurs and lorises, may be related to tarsierso Lemur-like adapoidso Some have derived features (Dental comb) linking them to modern lemurs and lorises Oligocene (34 MYA)- Cooler and drier than Eocene- but still warmer than today- Early anthropoid radiation- Mostly Old World anthropoids discovered at the Fayum in Egypt, Africa- Fayum depression - gold mine of fossils- First anthropoids (primitive monkeys) arose in Africa and later reached South America- 2 Genuses: Apidium and Aegyptopithecus- Apidium - squirrel sized primate that ate fruits and seeds. Was also an arboreal quadruped that lept and sprung- Aegyptopithecus - largest of the Fayum anthropoids, size of a modern howler monkey, short limbed, slow-moving arboreal quadruped, small brain, long snout. It bridges the gap between the Eocene fossils and the succeeding Miocene hominoids. Very primitive, no derived features from Old world or hominoids- By early Oligocene continental drift had separated New and Old World Miocene (23-5MYA)- Africa, Asia, and Europe a diverse and highly successful group of hominoids emerged- “Golden age of hominoids aka apes”- Significant transformations of climate and repositioning of land masses took place, by 23mya continents locations approximated those of today- Early Miocene was much warmer than Oligocene- Miocene hominoids were large-bodied, related to the ape-human lineage, not ancestral to any living form- Miocene hominoids geographically grouped into African forms, European forms, and Asian forms- African Forms (23-14mya): -From Kenya (east Africa) -Generalized and primitive hominoids -Genus Proconsul- European forms (16-11mya) -Very derived -Widely scattered localities in France, Spain, Italy, Greece, Austria, Germany, & Hungary -Genus Dryopitheucs and Ouranopithecus (10-9mya, Greek fossils)- Asian forms (15-5mya) -Largest and most varied group of Miocene hominoids -Genus Sivapithecus (from Turkey and Pakistan) -Highly derived Pliocene (5mya)- Time of global cooling after the warmer Miocene- Expanded savannahs and grasslands due to the cooling and drying- Warmer than it is today- Large polar ice caps formed Antarctica Pleistocene (1.8MYA-10,000 years ago)-AKA: Ice Age-First in which Homo Sapiens evolved-By the end of the Pleistocene humans were spread out all over the world-Marked by periodic advances and retreats of continental glaciations -Interglacials: Climatic intervals when continental glaciers retreat due to warm temps. in the north latitudes while the south latitudes becomes wetter -Hominins were severely affected especially in Europe and Northern Asia -Changing of availability of food resources -Changing of migration routes (Sahara desert expanded, blocking migration, ice sheets expanded making northern regions become uninhabitable and blocked by glaciers)-Broken up into the 3 parts: Lower, middle, and upper pleistocene - Lower (1.8MYA-780,000 years ago) - Middle (780-125,000 years ago) -Homo heidelbergensis -AKA: pre-modern humans of the middle pleistocene -Transitional species between H. erectus and H. sapiens -Probably an ancestor to modern humans and neandertals -Thrived in Africa and areas of Europe, some Asia -Split into 3 geographical groups (Africa, Europe, Asia) -Flatter face, a little brow ridge, widest part of head drifts upwards (around the ear) -Referred to as Archaic Homo Sapiens -Primitive traits: supraorbital Torus (brows), Low vault, large face, No forehead -Derived traits: Vault is thinner (bone is thinner), more vertical nasal (flatter nose sticking out like us), larger brain, Higher up breadth-Culture -Lived in natural land forms such as caves -Hearths (controlled fires) -Shelters -3 spears (wooden spears) -Acheulian levallois technique - Upper pleistocene (125,000 - 10,000 years ago) -Neandertals -AKA: Pre-modern Humans of the Late (upper) Pleistocene -Likely descendants of Homo heidelbergensis -Unique individuals in Europe and Middle East -During Upper Pleistocene (130-30kya) -Have lots of derived traits: stockier than sapiens and heidelbergensis, more robust inoverall body shape, exhibit pronounced region of the upper mid face (nose and cheekbones), large arching brow ridge, occiptal bun, projecting midface, shorter stockier, shorter limbs, wider at shoulder and pelvic region, less surface area to lose heat -Later found in areas where it was colder when glaciers started dissapearing -All of these are adaptations to the glacier environment -Can call them homo neanderthalensis or Homo Sapiens neanderthalensis -Culture: mousterian stone tool culture, cave residences Holocene (12,000 years ago - Today)- AKA: The Age of ManLCA—last common ancestorPhylogenetic tree: shows the evolutionary relationships among various speciesMolecular clock - a tool used to determine how long ago two different species diverged. Scientists look at the gene sequences of the two species, determine the amount of difference in the sequences, and by assuming a rate of constant mutation you can figure out how long ago they diverged.Ancestral traits/primitive traits - Traits present in a common ancestor Derived traits - Traits modified from the ancestral condition (does not show up in the common ancestor) aka unique traitsPlesiadapiforms - Primates from the Paleocene period that belong to the group plesiadapiforms; earliest known primates.POMA—what does this stand for? Primates Of Modern AspectProconsul - Miocene ape-like creature/hominoid geographically grouped under African forms, best known genus that postcranially resembles more a monkey than an ape. Derived features include the teeth