LABSPrimate Phylogenetics:- Analysis of DNA sequence differences used to make a phylogenetic tree, which depicts:o 1. Diveregences between particular organisms over time and in part portrays the 2. Degree of variation between current species- DNA mutations occur at a predictable rate, enabling a time estimate for these divergence events.o Those that show the greatest number of sequence differences are most distantly related they diverged from a common ancestor the greatest number of years ago- Geologic timeo Anthropological focus is in the Cenozoic era, the disappearance of the dinosaurs 65 myaPeriod mya Epoch Began myaQuaternary 1.8 HolocenePleistocene.011.8Tertiary 65 PlioceneMioceneOligoceneEocenePaleocene523345565NAME THE SIGNIFICANT EVENTS OF PRIMATE EVOLUTION:- Holocene: 10,000 years-present- Pleistocene (ice age): 1.7-10,000 years agoo Evolution of genus Homo- Pliocene: 5-1.7 myao Adaptive radiation of hominids – diversification of skillso Origin of genus Homoo Worldwide dry/cooling periodo Pre-glaciationo Savannahs and grasslands - Miocene: 23-5 myao “Golden Age of Apes”o First hominids appearo Proconsul Well-known genus of dental apes  East Africa 100-150 lbs Ape-like Y-5 dental pattern Lack taleo The Messinian Crisis Mediterranean Sea Effects on salinity - Oligocene: 34-23 myao Anthropoids (Apes, OW monkeys and humans) Similar to modern monkeyso Oligopithecidso Parapithecidso Propliopithecids (Aegyptopithecus) Well-documented genus from Africa Earliest accepted ancestor of OW monkeys and apes 13-18 lbs 2123 dental formula Arboreal/terrestrial quadruped- Eocene: 54-34 myao POMA: Primate of Modern Aspect Seeing modern traits Adapids and Omomyidso Prosimian-likeo Found in N. America and Europe- Paleocene:65-54 myao Rodent-like primateso First primate-like mammals- Fossil record of primateso While mammals first appear during the Mesozoic, they radiate (expand in numbers of species) during the Cenozoic – “Age of Mammals”Principles of Evolutionary Relationships- Homologies: similar attributes, called characters, from a shared common ancestor (p. 113)- Analogies: similar attributes from a common function- Ancestral traits: homologies that many organisms share with very distant ancestors and are not as informative- Derived traits: traits modified from the ancestral condition and are more diagnostic of particular evolutionary lineages- Clades = lineages- Taxonomy: the division of organisms into ordered groups or categories. The arrangement reflectsnatural relationships between the organismso The traditional taxonomic system has these main categories: Kingdom, Phylum, Class, Order, Family, Genus, Specieso Taxonomic organization of species is hierarchicalo Organisms are categorized based on exhibited physical similarities into smaller, more specific groupings- Species: individuals in a population that are capable of breeding and producing viable offspring- Speciation: process by which a news species evolves from an earlier species; the most basic process of macroevolutiono Allopatric: main cause is a geological isolation (river forming)o Peripatric: complete geological isolation (diurnal)o Parapatric: adjacent/overlapping niches (shows higher preference of mates)o Symphatric: genetic polymorphism (orange and white tigers that aren’t able to mate)- Phylogenyo Time componento Ancestor-descendant relationshipo Evolutionary systematics- Evolutionary systematics: the traditional approach for hypothesizing relationships between extinct and extant organismso Phylogenetic trees: constructed to incorporate time and display our proposed ancestor-descendant relationships Ancestral traits: characteristics inherited by a group of organisms from a common ancestor Derived traits: characteristics that are modified from the ancestral form and are diagnostic of evolutionary lineages Last common ancestor: the most distantly recognized relative- Based on recognition and interpretation of traits, and the time at which the organism lived, we can point to an extinct specimen as the LCAEarly fossil record- Teeth can be an indicator of morphology and the behavior of fossils- Mastication (chewing) muscleso Temporaliso Massetero The size, shape and form of muscles can influence the size, shape and form of the skeletalelements to which they are attached- Introduction to specimens of the early Pliocene human fossil record focusing on Australopithecineso Robust Australopithecines: hominids with strong temporalis and masseter muscles, a prominent sagittal crest and large and heavily worn posterior dentition Tough roots and seed require much chewing, reflected in its masticatory apparatuso Gracile Australopithecines:- Sagittal crest: a mounding of bone along the sagittal plane of the skull that provides extra attachment area for the temporalis muscle- Facial prognathism: the degree of projection of the lower face, particularly the maxillary region.o Large anterior dentition and facial prognathism go hand in hand- Supraorbital torus: the mounding of bone above the eye sockets expressed as a single ridge of bone or two separate bumpso Served as a strut to absorb shock from heavy masticatory forceso Sexual dimorphism present- Post-orbital constriction: pinching of the cranium right behind the brow ridges, usually associated with a smaller cranial capacity- Canines: large canines are indicative of a high degree of sexual dimorphism in a species- Diastema: the space between the maxillary canine and premolaro Makes space for a large mandibular canine during occlusion (closing of the mouth)- Posterior dentition: molars and premolars- A. africanus: 3.3-1.2 myao South Africao High facial prognathismo Supraorbital torus (brow ridges) presento Big teetho Small craniao Well-adapted bipedso Gracile - A. afarensis: 3 myao East Africao Lucyo Moderate facial prognathismo Supraorbital torus (brow ridges) presento Post-orbital constriction presento Posterior dentition largero Small craniao Gracile - A. boisei: 2.5-1.2 myao East Africao Robusto Sagittal crest presento High facial prognathismo Supraorbital torus (brow ridges) presento Post-orbital constriction presento Posterior dentition largero Large compared to aboveo Broad and flat cheeksLate fossil record – homo genus- Cranial capacity: a measure used to assess the volume of the skullo Not a direct assessment of intelligenceo Not