Evolution Final
Double Helix-structure of DNA
" Double Helix" Strands wrapped around each other. Joined by Hydrogen Bonds between bonds.
Medieval Europe
"Great Chain of Being" •Fixed Hierarchy •Elite at top (Royalty, Clergy) •Unchanging nature of classes of people & animals •Ranked by degree of their "perfection" •Each is a product of special creation •No intermediate forms
Sima del Elephante
"homo antecessor" found. also Mammal bone with percussive marks and Bovid vertebra with cutmarks.
Carnivory
( Small, Big, Small) small incisors large canines canassials (slicing molars and premolars) -short gut
Denis Diderot
( observe nature) (1713 - 1784) (Denis Did it right)•"Enlightenment" •Empiricism •Obtain knowledge by observing nature •Not by tradition, authority, scripture
A. africanus
(3.5 - 2.4 Ma)
Australopithecus Afarensis
(3.6 - 3.0 Ma) - small or no diastema, no honing facet - "post-canine megadontia" - large premolars and molars - premolars are more "molarized", more cusps. - ate tough, gritty food - reduced aggression and display in males - fairly prognathic - ape-sized brain - pronounced sexual dimorphism - long arms, short legs, flaring pelvis - bipedal, abductor muscles (gluteals) allow weight balance along midline - wedge-shaped sacrum - powerful climber - scapula - glenoid fossa points up --> suspensory - very adaptable: wooded riverine habitat at Hadar, arid savanna at Laetoli
A. afarensis at Laetoli
(3.6 Ma) - excavated by Mary Leakey - footprints of 3 individual A. afarensis individuals in carbonitite volcanic ash deposits, hardened by rainfall.
Ardipithecus ramidus
(5.8-4.4 Ma) - Baringo (Kenya) and Awash region (Afar Triangle) Aramis site (Ethiopia) - Later hominin dentition (small canines, thick enamel, etc.) - "Ardi" - female, short broad face, broad zygomatics (chewing) - less prognathic than chimpanzees - diet not exclusively frugivorous or abrasive, probably omnivorous. - arboreal and bipedal, palmigrade (palm-walking) quadruped
Orrorin tugensis
(6 Ma) - Baringo region of Kenya - chimp-like molars and anterior teeth, but human-like enamel thickness - grooves in humerus indicate climbing behavior
- Taung Child (3 - 2 Ma)
(A. africanus) - discovered by Raymond Dart - 3-5 years old, cranial endocast of the brain - talon and beak marks around orbits - canine pillars (distinguishing characteristic of A. africanus
- Mrs. Ples
(A. africanus) - initially called Plesianthropus - fairly small brain, bipedal - deep zygomatic bone (strong chewer)
- Little Foot (3.5 Ma)
(A. africanus) - most complete hominin fossil ever found - big toe may have been partially divergent - molars and premolars larger than A. afarensis, smaller front teeth
Primate characteristics
(Heterodont) Dental Formula (incisors,canines,premolars,molars) -most prosimians and all new world monkeys:2.1.3.3 -Old World Monkeys,Apes,Humans:2.1.2.3
Kimura-"Neutral Mutation Effect"
(Motto Kimura 1968) Many Mutations are silent, Neutral: No apparent effect on Organism.
Signs of cognitive advance
(from upper paleolithic) New technologies. exchange networks (trade.) economic intensification & planning (new foods). Symbolic aftifacts.
Homo erectus
(~1.8 Ma) - large body size - human-like teeth - obligate biped, good runner - human-like body proportions - first hominin outside of Africa - stone tool use (Acheulian) - considered first "real" member of Homo - "sagittal keel" - resembles a seam across top of skull - wedged back of skull
Important Early African Hominoids (Miocene) specimens
- Afropithecus, Morotopithecus, Proconsul africanus, and Kenyapithecus. - "honing facet" - canines overlap, rub against each other creating a flat area (facet) - "diastema" - gap where canines rest when mouth is closed - "perikymata" - tooth growth lines used to determine duration of enamel development. - Kenyapithecus had smaller canines, but still has diastema and honing facet - diverse diet and locomotion (quadrupedal, suspensory) - mostly frugivorous
Aegyptopythecus
- Early Haplorhine (Oligocene) - 2:1:2:3 dentition, completely enclosed orbits, high level of sexual dimorphism, quadrupedal (probably arboreal).
Australopithecus garhi (2.5 Ma)
- animal bones with tool cut marks found near fossils - ancestral to Homo? - apelike brain and proportions, but human-like teeth - contemporary with Homo
Adapis and Ida
- earliest Strepsirrhines (Eocene) - [primitive] 2:1:4:3 dentition, body weight ≤ 7 kg. - [derived] nails rather than claws, expanded visual cortex, reduced olfactory bulb.
Paranthropus robustus
- sexually dimorphic, large body size in general - enormous molars, massive mandible - brow ridges in male more defined - large brain size (due to large body size) - pneumatized facial bones (air pockets absorb chewing shock) - flat-faced - maxillary trigon - mass of bone in place of canine pillar - had human-like digits, possibly made tools
Sahelanthropus
- thicker enamel than chimpanzees, thinner than humans - large brow ridge (supraorbital torus) - intermediary in prognathism - foramen magnum below skull - small brain size (400 cc) - small canines, no honing facet
Self-awareness
-identify oneself as an individual -In Humans not developed at birth -most Animals don't have this -Some Apes Have!
Alloparenting
-langur (type of monkey) -8 females may hold infant on day 1 -why bond with others? -Greater evolutionary advantage
Social Learning in the Primate
-mother-infant Bond -But not innate -Mother must be properly socialized! -Learning is essential!
Non-human primate communication
-only humans speak -natural communication systems (call systems) -ASL experiments (apes) -cultural transmission -productivity -linguistic Displacement
Reproductive Strategies
-permanent bonding uncommon -female estrus cycle signaled -Temporary consortships
Tool Use
-prepares for the future -Attention to shape and size raw material -preconceived idea of finished product -complex behavior
Infanticide
-single male groups -Dominate male replaced -New male kills some/all infants -not wasting time/energy defending infants that aren't his
What's different about the human skull?
1. Globular Braincase. 2. Smaller Teeth & Jaws. cooking new foods?
Plato (424-348 BCE)
1. Species = type or kind of animals or plants 2. Have Essential Nature (Essence) 3. Species Are conforming to the same principles or course of action over time
Early Homo Sapiens derived traits:
1. large brain size (shared with neanderthals) 2. High rounded cranium. 3. Rounded occiput. 4. Flexed basicranium. 5. Reduced brow ridges. 6. Smaller teeth and Jaws. 7. Orthognathic (opposite of prgnathic) face. 8. Chin. 9. Gracile postcranial skeleton. 10 Tropical body proportions.
Problems with Using overall similarity to determine relationships:
1.primitive retensions some characters retained from distant ancestor, not useful for establishing more recent evolutionary relationships. 2.Convergence similar traits can evolve in distantly related species, reflect adaptations to similar conditions, not evolutionary relationships.
The origin of the genus Homo, Paranthropus, and stone tols occurred at...
2.5 Ma.
First appearance of Microliths (probably used with bow and arrow):
230 ka, twin rivers, zambia
Early europeans
40 ka = Homo sapiens (Cro-Magnons) [break in fossil record ~300 ka Homo neanderthalis. 780 ka Homo heidelberensis and dawn of handaxes! [another break in fossil record] 1.2 Ma "homo antecessor" no handaxes. 1.8 Ma Homo erectus ("Homo georgicus")
Redundancy-Of Code
64 possible base pairs(4*4*4), 20 amino acids. Different base pairs can code for same amino acid. E.g. aat,aac,gaa,gat,gac
First appearance of Pigment & Grindstones:
>285 ka
Homo Habilis ( OH)
?
Homo habilis and Homo rhudolfensis
?
Movius Line
Acheulian vs. Oldowan Boundary. Hand axes only found near africa!.
Chromosome Mutation
Affects whole stretches of DNA, Usually has negative consequences.
What genus and species does the Tuang child belong to?
Australopithecus Africanus.
Ernst Mayr
Biological species concept ("BSC") •Species is a reproductive community. •Find mates within species. •Don't usually mate outside species. •Species members resemble each other Because they are closely related to each other. The biological species concept is the most widely accepted species concept. It defines species in terms of interbreeding. For instance, Ernst Mayr defined a species as follows: "species are groups of interbreeding natural populations that are reproductively isolated from other such groups."The biological species concept explains why the members of a species resemble one another, i.e. form phenetic clusters, and differ from other species.When two organisms breed within a species, their genes pass into their combined offspring. As this process is repeated, the genes of different organisms are constantly shuffled around the species gene pool. The shared gene pool gives the species its identity. By contrast, genes are not (by definition) transferred to other species, and different species therefore take on a different appearance. This explanation should be compared with that given by the ecological species concept.Interbreeding between species is prevented by isolating mechanisms.
The facial buttressing specific to Australopithecus africanus are the
Canine Pillars
Zhougoudian
Cave system in Beijing China. Deposits ~ 40 M Thick. Divided into 10 Units (numbered bottom to top) Long occupation ~ 200,000 years? Dating problematic, Fauna -> 400 ka. O Isotpe: 130 - 600 Ka. Paleomag > 780 Ka.
Silent Mutation
Change in Genotype, No change.
Point Mutation
Change is single base pair or codon (which is much smaller)
Principles of Geology 1830
Charles Lyell (1797-1875) •Earth history •Gradual change •Long period of time
Evidence of activity at Zhougoudian
Chemical analysis shows bnes burned. Some bones burned after fossilization. Stone tools present (flakes & cores). Bear & hyena bnes present. Some bone fragments abraded -> transported by water or partially digested by carnivores. Few cutmarks. No wood ash or hearths present. Sediments water-laid. Conclusions: bones burned but not in cave. Tools and bone washed in from outside cave.
Australopithecus garhi was found with...
Cut-marked bone, causing researchers to question whether this species made stone tools.
Paranthropus Aethiopicus ( Black Skull):
Date: 2.5 ma Skull: sagittal crest, deep flaring zygoma, forward foramen magnum, moderate brow ridges Teeth: very large rear teeth, very small front teeth Epoch: Pliocene
Orrorin Tugensis:
Date: 6 ma Epoch: Miocene Site Found: Lukeino Formation, Baringo, Kenya Fossil Status: Femur and humerus fragments, teeth and jaw fragments Postcrania ( All of part of the Skeleton except Skull): Femur human like, humerus built for climbing Primitive Ape Like Features: Anterior teeth, small molars Derived Human like features: thick tooth enamel , possible adaptations to bipedalism is the humerus from climbing Teeth: small molars with thick enamel, chimp like anterior teeth Dating Method: By using radiometric dating techniques, the volcanic tuffs and lavas, faunal correlation and magnetostratigraphy, Tools: None Habitat: lakeshore and small streams Conclusions: Probably an Early Biped hominin. Orrorin tugenensis is considered to be the second-oldest known hominin ancestor that is possibly related to modern humans, and it is the only species classified in genus Orrorin.
Sahelanthropus Tchadensis:
Date: 7-6ma Epoch: Miocene Site Found: Toros-Menalla, Chad Fossil Status: Complete Skull, tooth and jaw fragments Brain Size : Small Ape Size , 320-380cc ( compared to human brain of 1350cc) Derived Hominin Features: Enamel thickness intermediate, large supraorbital torus ( Brow Ridge), reduced prognathism , anterior positition of foramen magnum (Biped), small canines, No honing facet , no canine diastema Primitive Ape Like Features : small brain size, Petrous portion (ear area) of temporal bone chimp like Petrous portion of temporal houses semicircular canals. Its important for the sense of balance. Quadrupeds orientated differently than bipeds Body Size: ? Skull: foramen magnum placed anteriorly ( Suggest Bipedal), massive brow ridges, relatively flat face Teeth: Reduced Canines, no honing facet (used to sharpen the posterior edge of the upper canine when the two teeth come into contact) , no diastema (space or gap between adjacent teeth in the dental row.) , intermediate enamel thickness (enamel: hard white substance covering the crown of a tooth) Habitat: Gallery forest, stream or lake margin. Aquatic animals show that the lake was fresh Graving bovids show that grass was nearby Elephants, giraffes and monkeys show that trees were present Conclusion: grassland with scattered trees ( wooded savanna) Tools: None Conclusions: May represent a common ancestor of humans and chimpanzee. The discoverers claimed that S. tchadensis is the oldest known human ancestor after the split of the human line from that of chimpanzees
DNA-
Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of blueprints or a recipe, or a code, since it contains the instructions needed to construct other components of cells, such as proteins and RNA molecules. The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in regulating the use of this genetic information. Watson and Crick-James Watson and Frances Crick found "Double helix".
Important European Hominoid specimen
Dryopithecus fontani (16-8 Ma) - found in 1856 France, suspensory.
Allen's rule of Thermoregulation
Elongated body form increases surface area, good for radiating heat, cools body in tropics, evaporation requires dry environment, savanna not forest.
Effects of Rapid Postnatal Brain Growth on social group
External stimuli during active phase of brain growth -> social learning.
Australopithecus garhi
Footnote: cut marked animal bones Site: Hata Member, Bouri Formation, Middle Awash, Ethiopia Date: 2.5 Ma Epoch: Pliocene Fossils: Skull BOU-VP-12/130, femur, humerus, radius, ulna, proximal pedal phalanx. Skull: Prognathic face, procumbent incisors, sagittal crest Teeth: Large anterior & posterior teeth, small diastema, tooth wear not flat. Postcrania: Human like femur-humerus ratio (long femur), apelike upper-lower arm ratio (long lower arm), sexually dimorphic. Brain size: ~450 cc Stone tools; none, but cut-marked animal bone associated with A. garhi fossils.Oldowan tools present at other sites in same time interval e.g. Gona.
Frugivory ( Big , small, small)-
Fruit eaters -big incisors -Bunodont -low molars Molars-thick Enamel -short gut
Sites within Atapuerca
Gan Dolina, Sima del Elephante, Sima de los Huesos
Omnivory( Big, Small. Intermediate)-
Generalist (bear,pigs,humans) -large incisors -bunodont molars -canine variable -medium-length gut
Molecular Cock
Genetic differences can show how recently two species shared a common ancestor. Molecular differences between paris of species are proportional to the time of their separation (Alan Wilson)
Erasmus Darwin
Grandfather of Charles Darwin •Wrote books about Evolution (in verse!) ("Zoonomia," Phytologia," "The Temple Of Nature") All Vertebrate Animals: Similar Body Structure due to Descent From Common Ancestor.
The site in Ethiopia where A. Afarensis was found is named...
Hadar/Afar
Hypsodont
High crowned. Grass or Leaf eating
Homo heidelbergensis is a direct ancestor to
Homo sapiens.
McBrearty & Brooks 2000
Humans originated in Africa. What behavioral changes there? Biological changes occurred in Africa at Origim of Homo Sapiens 300-200 ka. Social and behavioral changes followed over long period of time.
why are only mostly calvaria left in indonesia?
Hyena dines on homo erectus.
Gran Dolina
Infilled Cave System. 16 M thick. 11 levels. Hominins from layer 6. Date Layer > 780 Ka (paleomag) So ~800-900 ka? Along with Homo antecessor was found Oldowan like tools. 85 specimens representing 6 individuals. Fossil fagmented, have cutmarks -> cannibalism likely.
facts to know about Ramapithecus
It was once thought to be a hominin, it is now believed to be the female members of Sivapithecus, and it was found and named by an industrious Yale undergrad.
First appearance of stone projectile points:
Kapthurin Formation, Kenya, 285 ka
First appearance of Stone Blades:
Kapthurin Formation, Kenya, 510 ka
First appearance of Fishing (with harpoons)
Katanda, Zaire, 90 ka
First appearance of bone points
Katanda, Zaire, 90 ka
CLASSIFICATION OF HUMANS:
Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Mammalia Order: Primates Superfamily: Hominoidea Family: Hominidae Subfamily: Homininae Tribe: Hominini Genus: Homo Species: sapiens Subspecies: sapiens
Australopithecus Diet
Large molars and premolars which means tough and gritty food.
"Homo antecessor"
Late Homo erectus or early Homo Heidelbergensis?
Folivory ( small, big, big)-
Leaf eaters small incisors sharp,high Crowned Molars and premolars -long gut
Teeth Chart
Leaves Fruit Meat Incisors small large small Molars tall low tall Gut long short short
African, Homo erectus has a body shape that is
Long and narrow to cool the body in a savanna environment
Effects of Rapid Postnatal Brain Growth
Longer periods of helplessness (altriciality) & dependence on mother.
DNA sequencing
Many Different Methods DNA strands usually cut intro fragments. Early Methods: Gel Electrophoresis.
Omo Kibish Skeleton, Ethiopia Homo sapiens, ~195 ka.
Modern anatomy. Tropical body proportions. Gracile. Reliance on material culture (technology) rather than physical features as adaptation?
Neutral Mutation Effect
Motto Kimura(1968) Many mutations are silent, Neutral: No apparent effect on Organism.
Platyrrhines
New World Monkey
Earliest occupation of Europe in the south.
No good evidence for fire. Flake & core technology only: no handaxes! Handaxes appear after 700 ka. Suggests a second migration?
Catarrhines
Old World Monkeys and Apes
Steno's law of superposition
Oldest layers(strata) at bottom Youngest at Top
Stone Tools:
Oldowan - made by Homo habilis: core, hammerstone, and flakes. Rough, simple shape Acheulian - made by Homo erectus: hand axes, tear drop-shaped, chipped/shaped on both sides. Date to 1.6 Ma - 200 Ka.
Homo erectus was found where and with what?
Olduvai Gorge, Bed II. dated 1.2 Ma. Acheulian tools. Streams and Savanna environment.
Both Homo habilis and Paranthropus boisei have been found at FLK in Bed 1 at ...
Olduvai Gorge, northern Tanzania
Events at 2.5 Ma
Origin of Paranthropus ("Black Skull"), West Turkana Origin of Homo (Hadar, Baringo) Origin of Stone Tools (Gona, Lokalelei) Australopithecus garhi and cut-marked bone (Hadar)
History of Orrorin
Orrorin tugenensis is considered to be the second-oldest known hominin ancestor that is possibly related to modern humans, and it is the only species classified in genus Orrorin. The name was given by the discoverers who found Orrorin fossils in the Tugen Hills of Kenya. By using radiometric dating techniques, the volcanic tuffs and lavas, faunal correlation and magnetostratigraphy, the strata in which the fossils were found were estimated to date between 6.2 and 5.6 million years ago[1], during the Miocene. This find is significant because Orrorin is possibly an early bipedal hominin. The fossils found so far come from at least five individuals. They include a proximal femur, which is insufficient evidence to prove that it was bipedal, though some scholars suggest that Orrorin walked upright; a right humerus shaft, suggestive of tree-climbing skills but not brachiation; and teeth that suggest a diet similar to Paranthropoids.[clarification needed] The obturator externus groove on the posterior aspect of the neck of the fossil femur suggests that Orrorin tugenensis moved bipedally. The bunodont, microdont molars and small canines suggest that Orrorin ate mostly fruit and vegetables, with occasional meat. Orrorin was about the size of a modern chimpanzee. The team that found these fossils in 2000 was led by Brigitte Senut and Martin Pickford from the Muséum national d'histoire naturelle. The discoverers conclude that Orrorin is a hominin on the basis of its bipedal locomotion and dental anatomy; based on this, they date the split between hominins and African great apes to at least 7 million years ago, in the Messinian. This date is markedly different from those derived using the molecular clock approach, but has found general acceptance among paleoanthropologists. If Orrorin proves to be a direct human ancestor, then australopithecines such as Australopithecus afarensis ("Lucy") may be considered a side branch of the hominid family tree: Orrorin is both earlier, by almost 3 million years, and more similar to modern humans than is A. afarensis. The main similarity is that the Orrorin femur is morphologically closer to that of H. sapiens than is Lucy's; there is, however, some debate over this point. Other fossils (leaves and many mammals) found in the Lukeino Formation show that Orrorin lived in dry evergreen forest environment, not the savanna assumed by many theories of human evolution. Thus, the origins of bipedalism occurred in an arboreal precursor living in forest and not a quadrupedal ancestor living in open country. A recently published idea suggests that ancestral apes may have shared the technique used by modern orangutans of moving bipedally over small springy branches with the vertebral column oriented vertically (orthograde), using their arms for balance and keeping their legs straight. This kind of upright locomotion could have been used as a way of getting around on the ground when gaps opened in the forest canopy. Our closest extant relatives the gorillas and chimpanzees developed a flexed stance (with clinograde, (sloping) vertebral column) and are more adapted to tree climbing and to quadrupedal locomotion while on the ground. According to a minority of researchers, like humans, they have fused and strengthened wrist bones suggesting a shared period of knuckle walking.[2][3][4] After the fossils were found in 2000, they were held at the Kipsaraman village community museum, but the museum was subsequently closed. Since then, according to the Community Museums of Kenya chairman Eustace Kitonga, the fossils are stored at a secret bank vault in Nairobi.[5] • Baringo, Kenya • Site= kapsomin • Dated by Ar/Ar and paleomagnatism • Orrorin tugenensis Age 6 ma Teeth and jaws Post cranial bones Fossils may not represent some species Mixture of primitive and derived trait Anterior teeth= chimp like Molars small= chimp like Enamel thick= human like Deep corpus of mandible
The "black skull," KNM-WT-17000, is the oldest member of Paranthropus at 2.5 Ma. It belongs to which species?
P. aethiopicus
Which species are found i South African cane sites?
Paranthropus robustus and Australopithecus africanus.
Paranthropus Robustus
Paranthropus robustus was originally discovered in Southern Africa in 1938. The development of P. robustus, namely in cranial features, seemed to be aimed in the direction of a "heavy-chewing complex". Because of the definitive traits that are associated with this robust line of australopithecine, anthropologist Robert Broom erected the genus Paranthropus and placed this species into it. Paranthropus robustus (considered for a time by the scientific community as Australopithecus robustus) is generally dated to have lived between 2.0 and 1.2 million years ago. P. robustus had large sagittal crests, jaws, jaw muscles, and post-canine teeth that were adapted to serve in the dry environment that they lived in. After Raymond Dart's discovery of Australopithecus africanus, Broom had been in favour of Dart's claims about Australopithecus africanus being an ancestor of Homo sapiens. Broom was a Scottish doctor then working in South Africa who began making his own excavation in Southern Africa to find more specimens, which Dart had found earlier. In 1938, at 70 years old, Broom, excavating at Kromdraai, South Africa discovered pieces of a skull and teeth which resembled Dart's Australopithecus africanus find, but the skull had some "robust" characteristics. The fossils included parts of a skull and teeth; all dated to 2 million years old. Fossil sites found on Paranthropus robustus are found only in South Africa in Kromdraai,Swartkrans, Drimolen, Gondolin and Coopers. In the cave at Swartkrans, the remains of 130 individuals were discovered. The study made on the dentition of the hominins revealed that the average P. robustus rarely lived past 17 years of age. Paranthropus robustus became the first "robust" species of hominid ever uncovered well before P. boisei and P. aethiopicus. Broom's first discovery of P. robustus had been the first discovery of a robust australopithecine and the second australopithecine after Australopithecus africanus, which Dart discovered. Broom's work on the australopithecines showed that the evolution trail leading to Homo sapiens was not just a straight line, but was one of rich diversity. Typical of robust australopithecines, P. robustus had a head shaped a bit like a gorilla's with a more massive built jaw and teeth in comparison to hominins within the Homo lineage. Broom also noted the sagittal crest that runs from the top of the skull acts as an anchor for large chewing muscles. The DNH 7 skull of Paranthropus robustus, "Eurydice", was discovered in 1994 at the Drimolen Cave in Southern Africa by Andre Keyser, and is dated to 2.3 million years old, possibly belonging to a female. The teeth of these primates were larger and thicker than any gracile australopithecine found, due to the morphology differences Broom originally designated his find as Australopithecus robustus. On the skull, a bony ridge is located above from the front to back indicating where the jaw muscles joined. P. robustus males may have stood only 1.2m (4 feet) tall and weighed 54 kg (120 lb) while females stood just under 1 meter (3 feet 2 inches) tall and weighed only 40 kg (90 lb), indicating a large sexual dimorphism. The teeth found on P. robustus are almost as large as those of P. boisei. Broom analyzed his findings carefully and noted the differences in the molar teeth size which resembled a gorilla's a bit more than a human's. Other P. robustus remains have been found in Southern Africa. The average brain size of P. robustus measured to only 410 and 530 cc, about as large as a chimpanzee's. Some have argued that P robustus had a diet of hard gritty foods such as nuts and tubers since they lived in open woodland and savanna. More recent research suggests that this taxon was more of a dietary generalist,[1] and others have argued that they principally consumed hard and gritty resources as fallback foods only during time of nutritional stress.[2] • 1.8-1.6 ma • Kromdraai • Swart kraans • Homo and stone tools present after 2ma
How do we know that at least one species of hominin at Olduvai Gorge was using animals as food?
Piles of animal bones were found that showed evidence of being cracked to get at the nutritious bone marrow. In addition, cutmarked bone and stone tools with microwear were found.
First appearance of Shellfish:
Pinnacle Point, South Africa, 165 ka; Klasies, 110 ka
the ___ underwent adaptive radiation at 65 Ma following dinosaur extinction.
Primates/Mammals
Describe Homo erectus's migration away from africa
Rapid!, Not deliberate colinization. Migration & population expansion. 9,200 km from turkana to Beijing. If only 20/km per generation and 1 generation = 20 years then migration would take 9,200 years. Too short to detect with current dating methods. Appears instantaneous.
Australopithecus Socialized Behavior
Reduced canines = reduces aggressiveness in behavior
Primate dental formula
Reptile(~325 Ma) Homodont-all teeth in jaw alike, no precise occlusion Mammals(~200Ma)
Homo erectus fossils in Java
Sangiran vicinity, Java. 7 Calavaria (skull caps) 9 more complete skulls. 6 Mandibles/Maxillae. Total all sites: 40-50 individuals date ~ 750ka.
Othernames for homo erectus:
Sinanthropus, Homo ergaster, asian homo erectus non existant. Showed that homo erectus is highly variable.
Ardipithecus Ramidus ( Ground floor root):
Site: East African Rift Valley. Aramis, Middle Awash region of Afar, Ethiopia. Epoch: Pliocene Dates: c. 4.4 - 4.0 Ma Fossils: Teeth & jaws, occipital fragments, humerus, radius, ulna. Body size: c. 40 kg. Brain size: Apelike, precise size not known. Dating Method: Volcanic Strata Primitive Ape Like traits: No post canine megadontia ( Molars and Premolars are small), thin tooth enamel, small external auditory meatus ( ear tube) , powerful arms for climbing Derived Human Like traits: canines small and incisors like, no honing facet on premolar, forward position on foramen magnum Teeth: Canines large, posterior( back) teeth relatively small; no ape-like honing facet on canines; premolars not molarized; thin enamel; dental arcade shape similar to A. afarensis, but canines in line with posterior teeth like apes. Skull: Foramen magnum placed anteriorly( Biped) Postcrania ( everything except skull): Forelimb a mixture of ape-like and A. afarensis-like features, no adaptation for knuckle-walking. Habitat: Floodplain. Forest or woodland vegetation. Tools: None. Conclusion: Its distinguishing characteristics are bipedalism incorporating an arboreal grasping hallux or big toe, reduced canine teeth and a smaller brain size comparable to that of the modern chimpanzee.
Kenyanthropous platyops:
Site: Lomweki, Kenya Epoch: Pliocene Date: 3.5-3.2 Ma Fossils: Complete skull Skull: Moderate prognathism (flat face) Teeth: Small Molars Tools: None.
Australopithecus anamensis (lake):
Sites: Allia Bay & Kanapoi, East Turkana,Kenya Epoch: Pliocene Dates: Allia Bay: 3.9 Ma, Kanapoi: 3.4 - 3.1Ma Fossils: Tibia, humerus, temporal, teeth & jaws Primitive Traits Ape like: large canines, articulation of mandible , external auditory meatus , small ( ear hole) Derived Human like : flat wear on canine, no honing facet, thick enamel , valgus knee, shock absorber , small articulation for tibia, no mobile ankle and big toe, no knuckle walking Body size: 45-60 Kg, very dimorphic Brain size: Apelike, precise size not known. Teeth: Large canine, no honing facet on canine, thick enamel on all teeth Skull: Mandibular ( lower jaw) articulation & external auditory meatus size & shape chimp-like Postcrania: Bipedal, less flexibility in ankle & big toe than chimp, powerful climber Habitat: riverine floodplain, mixture of open savanna & woodland fauna. Tools: None. • Human traits: flat wear on canine , no honing facet, thick enamel • Chimp trait: large canine, articulate manible, external auditory meatus • Powerful climber • Bipedal locomotion • Very thick enamel
Australopithecus afarensis:
Sites: East African Rift Valley. Afar (Hadar), Ethiopia;Laetoli, Tanzania. Fossils: Many individuals, cranial, dental & postcranial remains. Footprints at Laetoli AL-288-1: "Lucy" 40% complete female partial skeleton. AL-333: "First family" AL-444-2: Nearly complete male cranium. Dates: Laetoli 3.5 Ma, Hadar 3.0-3.4 Ma. Epoch: Pliocene Body size: c. 25-60 kg. Height: c. 3'3" to 5'7". Very dimorphic, females c. 65% of male body weight. Brain size: Small (ape range): 400-500 cc. Teeth: Large dimorphic canines, diastema sometimes present, incisors fairly large, molarized premolars, molars large, low crowned with thick enamel, tooth rows converge at rear, third molar smaller than first and second molars. Skull: Prognathic, nuchal crest (a flange of bone in the occipital region of the skull that serves as the attachment of the nuchal musculature of the back of the neck.) & sagittal supraorbital torus in males, foramen magnum placed anteriorly. Postcrania: Bipedalfeatures: Human-like carrying angle of knee, shallow broad pelvis, big toe in line with other toes. Other features indicate possible climbing ability: Long forearms, curved finger & toe bones, upward-facing shoulder socket. Habitat: Woodland & semiarid savanna. Tools: None. • "southern ape from afar region" translation of the name • 60 individuals found to date • Dates 3.0-3.6 ma • 2 major sites: hadar (Ethiopia) and loetoli(Tanzania) • Biped with climbing abilities • Pelvis bowl shaped, and expanded sacrum support by body weight
Homo rudolfensis
Sites: Koobi Fora, Kenya. Date: c. 1.9 Ma. Epoch: Pliocene Fossils: Cranial, dental & postcranial specimens.KNM-ER 1470: Nearly complete cranium. Brain size: Large, c. 750 cc. Body size: ? c. 50 kg, probably dimorphic. Teeth: Large incisors & canines, molars & premolars broad. Skull: No supraorbital torus, face orthognathic (not prognathic). Postcrania: Femur & foot like later Homo, no climbing adaptation. Habitat: Semiarid savanna, locally wooded conditions. Tools: None directly associated with fossils, but Oldowan tools present at sites in same time interval.
Paranthropus robustus
Sites: Kromdraai, Swartkraans, South Africa Fossils: Many individuals, cranial, dental & postcranial remains. Dates: 1.8 - 1.6 Ma. Epoch: Early Pleistocene Brain size: c. 550-600 cc. Body size: Females c. 30 kg; males c. 40 kg. Diet: large quantities of low quality food ( roots, tubers, barks, stems , gritty food) small incisors and canines, flat wear Teeth: Parabolic dental arcade, very large molars & premolars with thick enamel, very small incisors & canines, no diastema, massive jaws, flat tooth wear. Skull: Low forehead, prominent sagittal crest in males, flat bony face, no canine pillar, large supraorbital torus in males, flaring zygomatic arch (is formed by the zygomatic process of temporal bone (a bone extending forward from the side of the skull, over the opening of the ear) and the temporal process of the zygomatic bone (the side of the cheekbone), the two being united by an oblique suture; the tendon of the Temporalis passes medial to the arch to gain insertion into the coronoid process of the mandible.), foramen magnum placed anteriorly. Postcrania: Similar to other Australopithecines, bipedal. Fingers capable of fine manipulation necessary for tool making. Habitat: Semiarid savanna, locally wooded conditions. Tools: Oldowan (but Homo present in same cave deposits), possible polished bone tools • Body size=36kg • Larger than africanus • Sexually dimorphic • Very large molars and premolars • Massive mandible • Tiny incisors and canines , both were vertically placed • Flat wear on big cheek teeth on molars and premolars • Small front teeth allow incisors and canines to be free • Sagittal crest for chewing muscles • Supraoribital torus ( brow ridges) • Low forehead • Flat face • Flaring zygoma (cheek bones) • Sagittal crest ( males) Hand of Robustus • Human thumb • Mobile • Robust • Power grip- thumb to palm and fingers • Precision grip- tip of thumb to finger tip • Thumb robust Termites • High fat , calorie, high yield Roots • Low calorie, high fiber and high yield Diet of Robustus • Jarman bell principal • Large body sizelow metabolism rate • Large quantities of low quality food • Repetitive chewing • Thick enamel • Gritty food Paranthropus Robustus Paranthropus (KWT 17000) • West turkana, Kenya • Called aethiopicus • Earliest and most primitive form • Small brain • Very prognathic • Very large rear teeth • Flaring zygoma • Complex sagittal
Paranthropus boisei
Sites: Olduvai, Tanzania; Koobi Fora & West Turkana, Kenya. Dates: 1.8 - 0.96 Ma. Epoch: Early Pleistocene Fossils: Many specimens, mostly cranial & dental. OH 5: Olduvai Gorge Bed I, adult male cranium("Zinjanthropus") KNM-ER 406: Koobi Fora, Adult male cranium KNM-ER 732: Koobi Fora, Adult female cranium. Brain size: Small c. 400-500 cc. Body size: Maximum 70 kg; Very dimorphic: females c. 70% male body weight. Teeth: Parabolic dental arcade, extremely large molars & premolars with thick enamel, extremely small incisors &canines, no diastema, very massive jaws, flat tooth wear. Skull: Massive cranium, low forehead, very prominent sagittal & nuchal crests, flat bony face, large subraorbital torus, extremely flaring zygomatic arch, no canine pillar, heart-shaped foramen magnum, placed anteriorly. Postcrania: Similar to other Australopithecines, bipedal. Habitat: Semiarid savanna, locally wooded conditions. Tools: Oldowan (but Homo present in same deposits).
Homo habilis
Sites: Olduvai, Tanzania; Koobi Fora, Kenya. Dates: 1.9 - 1.6 Ma. Epoch: Pliocene/early Pleistocene Fossils: Numerous cranial, dental & postcranial specimens.OH 7: mandible, parietal fragments, hand bones.OH 8: Nearly complete foot. OH 62: Partial skeleton.KNM-ER 1805, KNM-ER 1813: Partial crania. Brain size: Large, > 600 cc. Body size: 40 - 50 kg, probably dimorphic. Teeth: Parabolic dental arcade, large incisors & canines, no diastema, molars & premolars narrow, smaller than Australopithecus. Skull: Thin bones of cranial vault, high forehead, large braincase, no sagittal crest, flat bony face,small supraorbital torus, foramen magnum placed anteriorly. Postcrania: Long forelimbs, hand with ape-like features, foot mixture of features for bipedalism and adaptations for climbing. Habitat: Semiarid savanna, locally wooded Tools: Oldowan. • Brain size seems larger • Cranial vault bones thin • Association with stone tools • Incisors' and canines larger • Molars and premolars smaller
Australopithecus africanus
Sites: Taung, Sterkfontein, Makapansgat, South Africa. Epoch: Pliocene Dates: 2.3 - ~3.5 Ma. Fossils: Many individuals, cranial, dental and postcranial remains. Taung: Nearly complete juvenile cranium. Sterkfontein: "Mrs. Ples" (STS 5): Nearly complete adult cranium; "Little Foot":Nearly complete skeleton. Brain size: Small (ape range): < 450 cc. Body size: Similar to A. afarensis: c. 25 - 40 kg,Dimorphic. Teeth: Parabolic dental arcade, large molars & premolars with thick enamel, small incisors & canines, no diastema. Skull: "Dish-shaped" face, canine pillar, foramen magnum placed anteriorly, no sagittal crest on most specimens. Postcrania: Similar to A. afarensis. Habitat: Semiarid savanna. Tools: None. • 2.4-3.5 ma • Discovered in 1921 by Raymond dart • Taung infant • Sterk fontein • Makapan • Age of death 3-5 yrs old • Cause of death predation, talon and beak marks on skull • 1.8-1.6 ma • Kromdraai • Swart kraans • Homo and stone tools present after 2ma Africanus Teeth • Large rear teeth • Small front teeth • Canine pillars 1930 Africanus • Adult female • Mrs. Ples (nickname) • First called plesianthropus • Anterior position of foramen magnum means it was bipedal • Had a small brain • Deep zygomatics ( cheek bones) • Canine pillars • Concave ( dished shape facial profile) • Petrus portion of temporal bone • Houses semicircular canals • Important to sense balance • Both similar to afarensis Little Foot • Most complete hominin skeleton • Excavation at little foot site is siiberg • Robert broom discovered fossils of both africanus and robustus in south Africa
Paranthropus aethiopicus
Sites: West Turkana, Kenya; Omo, Ethiopia. Dates: 2.6-2.4 Ma. Epoch: Pliocene Fossils: Two complete crania, teeth & jaws. KNM-WT 17000 ("Black skull") adult malecranium, KNM-WT 17400 juvenile male partial cranium. Body size: Similar to A. boisei , very dimorphic. Brain size: small, c. 400 cc. Teeth: Very large posterior teeth, small anterior teeth, massive jaws, third molar smaller than first and second molars, flat tooth wear, tooth rows converge at rear. Skull: Very prognathic, very flared zygomatics, very prominent compound sagittal (The presence of this ridge of bone indicates that there are exceptionally strong jaw muscles. The sagittal crest serves primarily for attachment of the temporalis muscle, which is one of the main chewing muscles. Development of the sagittal crest is thought to be connected to the development of this muscle. A sagittal crest usually develops during the childhood of an animal in conjunction with the growth of the temporalis muscle, as a result of convergence and gradual heightening of the temporal lines.) & nuchal crests in male, flat cranial base, heart-shaped foramen magnum. Postcrania: None described. Habitat: Semiarid savanna, locally wooded conditions. Tools: None.
Important Asian Hominoid specimens
Sivapithecus (initially called "Ramapithecus brevirostrus") - thick tooth enamel, thought to have parabolic dental arcade - likely ancestor of orangutans
Mutation
Spontaneous change in genetic material, introduces novelty.
DNA Hybridization
Step 1. Extract DNA from Human and Chip Step 2. Snip Fragments of DNA from Human and Chimp, Heat up ,Determine melting Temperature. Step 3. Put strands of Human and Chimp DNA in Petri Dish ,cool off allow Hybrid strands to form. Step 4. Heat up Hybrid strand, Determine Melting Temperature. Differences in Melting Temps=overall Difference in DNA(number of different base pair) Hybridization alone can't solve Human-Chimp-Gorilla Relationship. DNA hybridization shows branching sequence.
The complete skeleton of "little foot" is currently undergoing excavation at the site of
Sterkfontein, South Africa
Carolus Linneus (Karl von Linné) (1707-1778)
Swedish naturalist •Binomial nomenclature (Genus & species names) •Species not conforming to the same principles or course of action over time)
where is Laetoli? How was the habitat at Laetoli different from other places where A. afarensis lived?
Tanzania. It was a more open, arid environment.
The first hominin to be found in africa was...
The Tuang child's skull
The flexed basicranium resulted in ->
The crossing of nasal & oral pathways. Can't drink & swallow at the same time. Causes choking hazard. Making sounds must be pretty important.
"Ardi" Complete fossil:
The fossil is the remains of a small-brained 50-kilogram (110 lb) female, nicknamed "Ardi", and includes most of the skull and teeth, as well as the pelvis, hands, and feet.[8] It was discovered in Ethiopia's harsh Afar desert at a site called Aramis in the Middle Awash region. Radiometric dating of the layers of volcanic ash encasing the deposits revealed that Ardi lived 4.4 million years ago. The fossil sheds light on a stage of human evolution about which little was known, more than a million years before Lucy (Australopithecus afarensis), the iconic early human ancestor candidate who lived 3.2 million years ago, and was discovered in 1974 just 74 km (46 mi) away from Ardi's discovery site. Researchers infer from the form of her pelvis and limbs and the presence of her abductable hallux, that she was a facultative biped: bipedal when moving on the ground, but quadrupedal when moving about in tree branches.[2][9][10] A. ramidus had a more primitive walking ability than later hominids, and could not walk or run for long distances.[11] The teeth suggest omnivory, and are more generalised than those of modern apes.[2] • Middle awash, Ethiopia • Baringo, Kenya- site tabarin, dated using ar/ar and paleomagnatism • Molars small but resemble molars of later hominins • Fairly thin enamel. • Another ardipithecus ramidus discovered in 1994 , dated 4.4 ma, found in awash, ethiopia • Ardi=grand , pithecus=ape, ramidus=root • Canines are small • No honing facet on premolars • Thin tooth enamel • Partial cranial base= foramen magnum forward • Arm bones= a climber? • Site had fluvial sediments deposited by a large river system
History of Sahelanthropus
The teeth, brow ridges, and facial structure differ markedly from those found in Homo sapiens. Cranial features show a flatter face, u-shaped dental arcade, small canines, an anterior foramen magnum, and heavy brow ridges. No postcranial remains have been recovered. Due to the distortion that the cranium has suffered, a 3D computer reconstruction has not been produced. Since no postcranial remains (bones below the skull) have been discovered, it is as of yet unknown whether Sahelanthropus tchadensis was indeed bipedal, although claims for an anteriorly placed foramen magnum suggests that this may have been the case, some paleontologists have disputed this interpretation of the basicranium. Its canine wear is similar to other Miocene apes.[2] Moreover, according to recent information, the femur of an hominid may have been discovered alongside the cranium but never published.[3] The fossils were discovered in the Djurab desert of Chad by a team of four led by Michel Brunet; three Chadians, Adoum Mahamat, Djimdoumalbaye Ahounta and Gongdibé Fanoné, and Frenchman, Alain Beauvilain.[4][5] All known material of Sahelanthropus were found between July 2001 to March 2002 at three sites (TM 247, TM 266 which yielded most of the material, and TM 292). The discoverers claimed that S. tchadensis is the oldest known human ancestor after the split of the human line from that of chimpanzees. The bones were found far from most previous hominin fossil finds, which are from Eastern and Southern Africa. However, an Australopithecus bahrelghazali mandible was found in Chad by Beauvilain A., Brunet M. and Moutaye A.H.E. as early as 1995.[6] Sahelanthropus may represent a common ancestor of humans and chimpanzees; no consensus has been reached yet by the scientific community. The original placement of this species as a human ancestor but not a chimpanzee ancestor would complicate the picture of human phylogeny. In particular, if Toumaï is a direct human ancestor, then its facial features bring the status of Australopithecus into doubt because its thickened brow ridges were reported to be similar to those of some later fossil hominids (notably Homo erectus), whereas this morphology differs from that observed in all australopithecines, most fossil hominids and extant humans. Another possibility is that Toumaï is related to both humans and chimpanzees, but is the ancestor of neither. Brigitte Senut and Martin Pickford, the discoverers of Orrorin tugenensis, suggested that the features of S. tchadensis are consistent with a female proto-gorilla. Even if this claim is upheld, then the find would lose none of its significance, for at present precious few chimpanzee or gorilla ancestors have been found anywhere in Africa. Thus if S. tchadensis is an ancestral relative of the chimpanzees (or gorillas) then it represents the first known member of their lineage. Furthermore, S. tchadensis does indicate that the last common ancestor of humans and chimpanzees is unlikely to resemble chimpanzees very much, as had been previously supposed by some paleontologists.[7] • [8] Unfortunately, the exact age of the fossil is somewhat hard to determine. While molecular clocks are increasingly found to be far more unreliable than initially believed[9] sediment isotope analysis which yielded an age of about 7 million years is generally considered quite reliable. In this case however, the fossils were found exposed in loose sand; co-discoverer Beauvilain cautions that such sediment can be easily moved by the wind, unlike packed earth.[10] In fact, Toumaï was probably reburied in the recent past. Taphonomic analysis reveals the likelihood of one, perhaps two, burial(s) which seemingly occurred after the introduction of Islam in the region. Two other hominid fossils (a left femur and a mandible) were in the same "grave" along with various mammal remains.The sediment surrounding the fossils might thus not be the material the bones were originally deposited in, making it necessary to corroborate the fossil's age by some other means.[11] The fauna found at the site - namely the anthracotheriid Libycosaurus petrochii and the suid Nyanzachoerus syrticus - suggests an age of more than 6 million years, as these species were probably extinct already by that time.[1
Why do some researchers dispute the taxon of Homo rudolfensis?
They argue it may represent male individuals of Homo Habilis
Cladistics Goal:
To reconstruct Evolutionary relationships. method: Identify monophyletic groups and clades Monophyletic groups are defined on basis of shared derived traits. is a form of biological systematics that classifies species of organisms into hierarchical monophyletic groups. It can be distinguished from other taxonomic systems, such as phenetics, by its focus on shared derived characters (synapomorphies). Previous systems usually employed overall morphological similarity to group species into genera, families and other higher level classification; cladistic classifications (usually trees called cladograms) are intended to reflect the relative recency of common ancestry or the sharing of homologous features. Cladistics is also distinguished by its emphasis on parsimony and hypothesis testing (particularly falsificationism), rather than subjective decisions that some other taxonomic systems rely upon[1].
First appearance of Trade & Exchange:
Transport of obsidian for ~200 km at ~130 ka, Mumba, Tanzania & Muguruk Kenya
What was found at Nariokotome, and why is it significant?
Turkana boy was found. 8 years old. Homo erectus. Teeth showed that they had an accelerated maturation rate
The glenoid fossa of the scapula in the Dikika hominin points ___ like other suspensory primates.
UP!
Synapomorphy
a derived character state that is shared by two or more taxa and is postulated to have evolved in their common ancestor.• Shared derived trait
Ardipithecus ramidus was probably a(n)
above branch quadruped and bipedal walker.
"Paedomorphosis"
adult descendent looks like juvenile ancestor, descendent does not develop full suit of ancestor's adult traits.
Hominidae
african apes + humans
Taxon (plural:taxa):
any named group in Linnaean classification (e.g.genus,species,family). taxa defined by their anatomical similarities. taxa grouped in a heirarchy. A taxon (plural: taxa) is a group of (one or more) organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement. Defining what belongs or does not belong to such a taxonomic group is done by a taxonomist. It is not uncommon for one taxonomist to disagree with another on what exactly belongs to a taxon, or on what exact criteria should be used for inclusion.
Hominoidea
apes
Base Pair
base pair is bonded by hydrogen bond. Bases are like Purines-Adenine and Guanine. Base is sugar phosphate "back bone". Bonds need to complement each other. In molecular biology, two nucleotides on opposite complementary DNA or RNA strands that are connected via hydrogen bonds are called a base pair (often abbreviated bp). In the canonical Watson-Crick base pairing, adenine (A) forms a base pair with thymine (T), as does guanine (G) with cytosine (C) in DNA. In RNA, thymine is replaced by uracil (U).
Approximately how old was the Tuang Child when it died?
between 3 and 5 years old
Willi Hennig
classification should reflect phylogeny (evolutionary relationships) names matter. In biology, phylogenetics is the study of evolutionary relatedness among various groups of organisms (for example, species or populations), which is discovered through molecular sequencing data and morphological data matrices. The term phylogenetics is of Greek origin from the terms phyle/phylon (φυλή/φῦλον), meaning "tribe, race," and genetikos (γενετικός), meaning "relative to birth" from genesis (γένεσις, "birth"). Taxonomy, the classification, identification, and naming of organisms, has been richly informed by phylogenetics but remains methodologically and logically distinct.[1] The fields overlap however in the science of phylogenetic systematics - often called "cladism" or "cladistics" -, where only phylogenetic trees are used to delimit taxa, which represent groups of lineage-connected individuals.[2] In biological systematics as a whole, phylogenetic analyses have become essential in researching the evolutionary tree of life.
eolian(=aeolian)
deposited by the wind
What are some traits that allow homo erectus to run?
elongated legs, tendons (e.g. hamstrings), Arches of foot(provide spring for running?), endurance running possibly used for hunting.
Dmanisi Stone artifacts
flakes & cores only, no handaxes!. Suggests hominins left africa before handaxes were invented.
Hylobatidae
gibbons
Paninae
gorillas and chimpanzees
Homininae
humans and extinct bipeds
Dmanisi
in Georgia.Homo erectus mandible, partial skeleton and cranium found there.
Paranthropus boisei
initially called "Zinjanthropus" - discovered by Mary Leakey - largest molars and premolars of any hominin - tiny incisors - enormous temporal fossa - extreme postorbital constriction - sagittal crest, flaring zygoma, flat face
Homo Habilis ( OH)
is a species of the genus Homo, which lived from approximately 2.3 to 1.4 million years ago at the beginning of the Pleistocene period.[1] The discovery and description of this species is credited to both Mary and Louis Leakey, who found fossils in Tanzania, East Africa, between 1962 and 1964. [2] Homo habilis (or possibly H. rudolfensis) is the earliest known species of the genus Homo. In its appearance and morphology, H. habilis is thus the least similar to modern humans of all species in the genus (except possibly H. rudolfensis). H. habilis was short and had disproportionately long arms compared to modern humans; however, it had a less protruding face than the australopithecines from which it is thought to have descended. H. habilis had a cranial capacity slightly less than half of the size of modern humans. Despite the ape-like morphology of the bodies, H. habilis remains are often accompanied by primitive stone tools (e.g. Olduvai Gorge, Tanzania and Lake Turkana, Kenya). Homo habilis has often been thought to be the ancestor of more gracile and sophisticated Homo ergaster, which in turn gave rise to the more human-appearing species, Homo erectus. Debates continue over whether H. habilis is a direct human ancestor, and whether all of the known fossils are properly attributed to the species. However, in 2007, new findings suggest that the two species coexisted and may be separate lineages from a common ancestor instead of H. erectus being descended from H. habilis.[3 omo habilis is thought to have mastered the Olduwan era (Early Paleolithic) tool case which utilized stone flakes. These stone flakes were more advanced than any tools previously used, and gave H. habilis the edge it needed to prosper in hostile environments previously too formidable for primates. Whether H. habilis was the first hominin to master stone tool technology remains controversial, as Australopithecus garhi, dated to 2.6 million years ago, has been found along with stone tool implements at least 100,000 - 200,000 years older than H. habilis. Most experts assume the intelligence and social organization of H. habilis were more sophisticated than typical australopithecines or chimpanzees. Yet despite tool usage, H. habilis was not the master hunter that its sister species (or descendants) proved to be, as there is ample fossil evidence that H. habilis was a staple in the diet of large predatory animals such as Dinofelis, a large scimitar-toothed predatory cat the size of a jaguar.[5] H. habilis used tools primarily for scavenging, such as cleaving meat off carrion, rather than defense or hunting. Homo habilis is thought to be the ancestor of the lankier and more sophisticated Homo ergaster, which in turn gave rise to the more human-appearing species Homo erectus. Debates continue over whether H. habilis is a direct human ancestor, and whether all of the known fossils are properly attributed to the species. Homo habilis co-existed with other Homo-like bipedal primates, such as Paranthropus boisei, some of which prospered for many millennia. However, H. habilis, possibly because of its early tool innovation and a less specialized diet, became the precursor of an entire line of new species, whereas Paranthropus boisei and its robust relatives disappeared from the fossil record. Homo habilis may also have coexisted with Homo erectus in Africa for a period of 500,000 years.[6 • Brain size seems larger • Cranial vault bones thin • Association with stone tools • Incisors' and canines larger • Molars and premolars smaller
Taphonomy
is the study of decaying organisms over time and how they become fossilized.
Co-Evolution
leigh van valen • 1.) Change in species A • 2.) Change in Species B • One species is getting more of food supply than another so other species has to change
Strepsirrhines
lemurs and lorises (prosimians)
Bunodont
low crowned fruit eating, Omnivory
Cercopithecoidea
monkeys
"absolute(=chronometric) dating
most chronometric methods are Radiometric or Isotopic methods based on decay of radioactive isotopes.
Michael Bush,
one of Don Johanson's students, made another major discovery in 1975: near Lucy, on the other side of the hill, he found the "First Family", including 200 fragments of A. afarensis. The site of the findings is now known as "site 333", by a count of fossil fragments uncovered, such as teeth and pieces of jaw. 13 individuals were uncovered and all were adults, with no injuries caused by carnivores. All 13 individuals seemed to have died at the same time, thus Johanson concluded that they might have been killed instantly from a flash flood. On September 20, 2006, Scientific American magazine presented the findings of a dig in Dikika, Ethiopia, a few miles from the place where Lucy was found. The recovered skeleton of a 3-year-old A. afarensis girl comprises almost the entire skull and torso, and most parts of the limbs. The features of the skeleton suggest adaptation to walking upright (bipedalism) as well as tree-climbing, features that match the skeletal features of Lucy and fall midway between human and humanoid ape anatomy. "Baby Lucy" has officially been named "Selam" (meaning peace in most Ethiopian languages).[22] urther findings at Afar, including the many hominin bones in site 333, produced more bones of concurrent date, and led to Johanson and White's eventual argument that the Koobi Fora hominins were concurrent with the Afar hominins. In other words, Lucy was not unique in evolving bipedalism and a flat face. Recently, an entirely new species has been discovered, called Kenyanthropus platyops, however the cranium KNM WT 40000 has a much distorted matrix making it hard to distinguish (however a flat face is present). This had many of the same characteristics as Lucy, but is possibly an entirely different genus. Another species, called Ardipithecus ramidus, was found by White and colleagues in the 1990s. This was fully bipedal, yet appears to have been contemporaneous with a woodland environment. Scientists have not yet been able to draw an estimation of the cranial capacity of Ar. ramidus as only small jaw and leg fragments have been discovered thus far.
Pongidae
orangutans
Insectivory Origins Hypothesis
stereoscopic vision,grasping hands and feet also good for Hunting insects
Haplorrhines
tarsiers, new world and old world monkeys (simians)
Heterodont
teeth in different positions in jaws different shapes, different functions -teeth occlude
Genome
the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA.
Lithostratigraphy
the study of geologic deposits and their formation, stratigraphic relationships, and relative time relationships based on their lithologic (rock) properties.
Shared Derived traits
used to define monophyletic groups, clades
Nariokotome ("Fossil Boy")
~ 1.6 Ma - West of Lake Turkana (in the Great Rift Valley in Kenya) - adolescent boy, very complete skeleton - about 8 years old, very early maturity - 805 cc brain capacity - social learning more important - long, narrow body form: adaptation to tropical region
Gregor Mendel
• "Particulate nature of inheritance"
Mendel and Genetics
• "particulate" nature of inheritance . Was published in 1867 and rediscovered in 1900. • Genes are "particles" in pairs where one is inherited from each parent. • Alleles are different versions of gene. One inherited from each parent . Dominant allele is expressed where the recessive allele is not expressed.
Natural Selection: Mechanism:
• 1. Sexual reproduction produces variation (Not all offspring are alike). • 2. Some offspring better suited to conditions than others, so: • 3. Produce more offspring than others ('Fitness' = Reproductive fitness). • 4. Over many generations produce enough change to result in new species. • "Struggle for survival" • Elimination of the "Unfit" • "Differential Reproduction"
Macro Evolution : Special Cases
• 1.) Adaptive radiation : sudden appearance many closely related species. • 2.) Mass extinction: Global cause
Cladogenesis Splitting " How does This Happen"
• 1.) Allopatric Model: Species isolated geographically • 2.) Sympatric Model: Species live in the same area , but use different resources ( Different Adaptations occupy different 'Niches' )
Isolating Mechanisms
• 1.) Morphological Differences ( hair color, body shape) • 2.) Genetic Incompatibility • 3.) Behavioral Differences ( posture, vocalizations) • 4.) Mate Recognition involves both morphological and behavioral traits
Problems Using Overall Similarity to determine Relationships
• 1.) Primitive retentions: Some characters retain from distant ancestor. Not useful for establishing more recent evolutionary relationships. • 2.) Convergence: Similar traits can evolve in distantly related species. Reflect adaptations to similar conditions , not evolutionary relationships.
Continental Drift and what Evidence Supports it
• 1.) fit of the continents • 2.) plants and animals match • 3.) The rocks match • 4.) Ice movement matches • 5.) Climates were different, positions do not match
Tempo of Macroevolution
• 1.) gradual change (Darwin) -slow gradual accumulation of changes produces a new species
Punctuated Equilibria
• 1.) long periods: no change • 2.) Punctuated by short periods of sudden change • 3.) New species appear suddenly
Microevolution
• 1.) occurs within species • 2.) change in Allele frequencies. • Mechanisms that can change Allele frequencies are a.) Mutation: appearance of new alleles. b.) Natural Selection: Some individuals produce more offspring than others. • Positive Selection ( directive selection) • Negative Selection ( Purifying selection) • Mutation - raw materials for natural selection. Radiating parrot chromosomes • Small changes ( changes in gene frequencies) • Short period of time • Takes place within a population
Lamarck
• 1.True: One Species Can Give Rise To Another • 2. False: Mechanism: Inheritance Of Acquired • Characteristics: Characteristics Acquired During Animal's Life Passed On To Offspring
Difference in 1470 and 1813
• 1470 larger brain size , body size and tooth size and a flatter face • Small supraorbital torus • 1813 smaller brain size , body size and tooth size , less flat face • Larger supraorbital torus
Darwin's ideas of evolution
• 1837: Began Notebooks On Transmutation Of Species • "Evolution = Descent with Modification" Takes place over generations. • Needs a long period of time. Earth changes, so animals & plants change (adaptation).
More Mechanism that can change Allele Frequencies
• 3.) Assortive Mating: Mate selection not random. Because they have the same Allele • 4.) Inbreeding: Close relatives more likely to share alleles • 5.)Gene flow: Population movement. Migration introduces new alleles. It means bringing your alleles to a new population. • Assortive mating emphasis differences within population.
Microevolution: mechanisms that cause a change in Allele Frequencies
• 3.) genetic drift small population chance elimination of rare alleles • 4.) Population bottleneck or • 5.) Founder effect Small founding population may not resemble parent population • Caused by population crisis or crash
Australopithecus afarensis at Hadar
• 3.0-3.4ma • "lucy" 40% complete skeleton. Was found in a sandy stream, channel environment • Al333 "first family" in 1975, 200 specimens, 18 individuals at 3.2 ma • AL 444 "son of lucy" • Most scientists believe that afarensis is ancestral to later homins
Macroevolution "how do new species appear"
• 4 Basic kinds of evolutionary Event A.) Stasis: Lineage shows no change ( Lobe finned fish) B.) Extinctions : Lineage terminates C.) Anagenesis: Gradual evolution within lineage Darwin was thinking about this when he wrote the origin of species D.) Cladogensis: Splitting • Lineage : ancestor descendant series of individuals, populations or species throughout time. YoumomGrandmaGreat Grandma
Monophyletic Group
• A group of species descended from a common ancestor they are more closely related to each other than to species outside the group.
Effects of Changing Insulation
• A.) Air and sea temperature ( both averages and seasonal) • B.) Ice volumes ( Both at poles and at high altitudes) • C.) Sea Level ( cold = more ice = sea level drops) ( Warm = less ice = sea level rises) • D.) Cold dry conditions and high winds = windblown , known as loess
1930 Africanus
• Adult female • Mrs. Ples (nickname) • First called plesianthropus • Anterior position of foramen magnum means it was bipedal • Had a small brain • Deep zygomatics ( cheek bones) • Canine pillars • Concave ( dished shape facial profile) • Petrus portion of temporal bone • Houses semicircular canals • Important to sense balance • Both similar to afarensis
Quarry 'M' Fayum, Egypt
• Aegyptopithecus 31-37 ma Oligocene • Haplothine, catarrhine • Diet fruit and leaves • Reduced alefactory bulb • Increased visual cortex • Completely enclosed orbit • Sexually dimorphic • Body size is larger in male than female • Canines larger in male • Sagittal crest on males not females )( on head • quadrupedal
Paranthropus Dates
• Aethiopicus- 2.7-1.9 ma • Boisei-2.3-1.4 ma • Robustus-1.8-1.6ma • Boisei seems to be descended from paranthropus aethiopicus
Chromosome Mutation
• Affects whole stretches of DNA • Usually has negative consequence
Plate Tectonics
• Alfred Wegener ( 1880-1930) in 1915 wrote the first edition of The origin of continents and oceans , which outlined Wegener 's theory of continental drift
Sahelanthopus environment
• Aquatic animals show that the lake was fresh • Graving bovids show that grass was nearby • Elephants, giraffes and monkeys show that trees were present • Conclusion: grassland with scattered trees ( wooded savanna)
Chromometric Methods
• Are radiometric or isotope methods which are based on decay of radioactive isotopes • 1.) measure amount of radioactive isotope left (parent) • 2.) measure amount of decay product (daughter)
Milankovitch
• Astronomical forcing of global climate • 1.) Changes in shape and orientation of earths orbit • 2.) Differences in distance and angle of earth and sun • describes the collective effects of changes in the Earth's movements upon its climate, named after Serbian civil engineer and mathematician Milutin Milanković. Milanković mathematically theorised that variations in eccentricity, axial tilt, and precession of the Earth's orbit determined climatic patterns on Earth. • The Earth's axis completes one full cycle of precession approximately every 26,000 years. At the same time, the elliptical orbit rotates, more slowly, leading to a 21,000-year cycle between the seasons and the orbit. In addition, the angle between Earth's rotational axis and the normal to the plane of its orbit moves from 22.1 degrees to 24.5 degrees and back again on a 41,000-year cycle; currently, this angle is 23.44 degrees and is decreasing. • Other astronomical theories were advanced by Joseph Adhemar, James Croll and others, but verification was difficult due to the absence of reliably dated evidence and doubts as to exactly which periods were important. Not until the advent of deep-ocean cores and a seminal paper by Hays, Imbrie and Shackleton, "Variations in the Earth's Orbit: Pacemaker of the Ice Ages", in Science, 1976,[1] did the theory attain its present state.
Generalist ( Omnivores)
• Bears , pigs, humans • Large incisors • Bunodont molars • Canines variable • Short-medium gut
Asian Hominoids
• Best fossil area= potwar plateau , siwalik hills • Pilbeams evolutionary scheme of 1970s • Asia was earliest place to look for ancestors of apes and us. • 1980 's DNA hybridization shows difference in human -chimp DNA is only 2-3% difference, divergence must be later • Difference to tell difference from male and female teeth is that female has short and broad jaw, while male has long and narrow
Archbishop Ussher
• Biblical Chronology: Counted generations • Concluded Date of • Creation = 4004 B.C. • (Now know age of earth = 4.5 billion yrs)
Fruit Eaters ( Frugivores)
• Big Incisors • Bunodont Molars • Short Gut
Afarensis Foot
• Big toe in line with other toes • Expanded heel • Toes shorter than ape, but are longer than human, toes curved • Flexible ankle • Foot weight transfer very similar to humans
Criteria for Homininae
• Bipedal • Different from chimps and gorillas • Resemble later hominins
Richard Leakey and KNM ER 1470 now called Homo rudolfensis
• Body size 40-50 kg • Large brain 775 cc • Oldowan artifacts
Paranthropus Robustus
• Body size=36kg • Larger than africanus • Sexually dimorphic • Very large molars and premolars • Massive mandible • Tiny incisors and canines , both were vertically placed • Flat wear on big cheek teeth on molars and premolars • Small front teeth allow incisors and canines to be free • Sagittal crest for chewing muscles • Supraoribital torus ( brow ridges) • Low forehead • Flat face • Flaring zygoma (cheek bones) • Sagittal crest ( males)
Australopithecus Garchi and cutmarked bone (hadar)
• Bouri formation, middle awash Ethiopia • Brain size ape like • Ape like body proportions • Anterior teeth larger which is homo like Cutmarked Bone • Bovid manible with cut marks made by stone tool for meat and protein • Bovid limb- one with cut marks made by Hammerstein for marrow or fat.
Cheek teeth
• Bunodont: Low Crowned, used for fruit eating , omnivory • Hypsodont: High crowned, used for grass or leaf eating • Lophodont or Selendont: complex cusps, used for grass or leaf eating
Teeth of Australopithecus
• Canines are intermediate in size between chimp and human • Small or no diastema • No honing facet • Molarized premolars • Molars increase in size front to back • Very thick enamel • Post canine megadontia • Reduced canines- reduced aggressiveness and display • Large molars and premolars • Tough gritty food
Isotopic Method on Ardi
• Carbon, plants metabolize carbon differently. Such as C3 plants in tropics.C4 in plant tropics • Grass, animals eat plants, animal tissues reflect c3/c4 ratio of the diet • C3 is found in trees and shrubs • C4 is found in grass
Origin of the Gensus Homo
• Chemeron formation , baringo Kenya • Larger brain • Human like jaw articulation • Expansion of brain affects relative position of articulation of manible • Site number two, hadar formation, baringo Kenya • Human like teeth, larger front teeth, smaller rear teeth, cusp patterns and palate dimensions
Savanna Hypothesis
• Chimp=forest and Humans=savanna • This theory is wrong, first creatures walking on two feet lived in the forest • McBrearty found chimp teeth fossil in middle of rift valley , she worked in the kapthurin ( Baringo, Kenya) • Human fossils were found in stream sediments and chimp fossils were found in lake sediments
Linnaeus (1707-1778)
• Chimps were Homo troglodytes • Humans are homo sapiens • Now chimps are pan troglodytes
Darwin
• Climate forces evolution • 1.) earth changes • 2.) animals and plants have to change to survive
How are Chimps and Humans Different
• Coding vs non-coding regions • Rapidly vs slowly evolving regions How similar? • Direct comparisons 99% identical • If included insertions and deletions 94% identical
Oxygen Isotopes as proxy for sea Temperature
• Common isotopes of oxygen O^18 and O^16 • Ice takes up O^16 (light) • In cold periods sea water is high in O^18 • Tissues of marine animals have same isotopic composition as surrounding water
Ardi Discribed
• Date 4.4 ma • Bones chewed by carnivores • Buried in fluvial sandy clay • Wetting and drying of clay led to the expansion and contraction of fragmentation of fossils • Height=4 ft • Body weight 110lbs • Female- small canines and brow ridges • Body Size dimorphism similar to pan • Short broad face • Zygomatic cheek broad and forward • Intermediate between chimp and autralopithecus • Anteriarly face foramen magnum • Brain size 300-350 cc, smaller than chimp • Ardipithecus doesn't protrude as much as chimp • Incisors smaller than frugivores apes • Molars enlarged but smaller than australafarensis • Canine smaller than chimpanzee • Low bunodont cusp on molars • Enamel thickness, intermediate between chimp and human, no honing facet of premolar • Buried in fluval and sandy clay • Primitive traits: small brain size • Derived traits: small canines, no honing facet • Intermediate traits: enamel thickness progathism. • Incisors smaller than frugvorous apes incisors • Molars enlarged but smaller than Aust. Afarensis
A few comments about Dates
• Dates always have a range of uncertainty • Few methods date fossils directly • Most methods date rocks • Most know geology • Date usually is a time range ( Min, Max) = bracketing
Dervived Hominin
• Dental features • Reduced canines • Post canine megadontia • Thick tooth enamel • Sahelanthropus-7ma • Orrorin-6 ma • Sahelanthropus dating from fossil found 7.4-5.3 ma • 44 taxa , best matches is the lukeino formation 6 ma • Nawata formation Kenya = 7.4-5.3 ma • Date of 7 ma for sahelanthropus supported by dating sediments using experimental method
Tephrostratigraphy( Volcanic)
• Deposits of each eruption have diagnostic chemical signature • Air-full deposits are widespread • Ash deposits is rapid • Many contain mineral phases for radiometric dating • Lava material layered from the lightest heaviest
Dikika Child
• Dikika Australopithecus afarensis child • Age of death 3.5 yrs( from tooth eruption) • Environment. Wooded grassland, catfish, bavids= both open and closed habitat forms. Hadar had become a bit more open over time. Swamp River, flood plain and lake margin. Use trees for sleeping and protection.
Mary Leakey Idea
• Dk site is the remains of an ancient shelter • Now thought to be natural arrangement of stone Home base Hypothesis • Emphasizes similarity to modern hunters and gatherers Idea • Food sharing • Sexual division of labor • Socializing • Resting • But many bones have tooth marks at oldoman are also active at sites. Might be dangerous to hang out. Sites were swampy. So nile crocodile may have been active • Carnivores attracted to meat and bones • Sites are dangerous places , not for socializing. Wild dogs work as a pack, gr
Magnetic Anomalies
• Earths magnetic poles reverse at irregular intervals. Position at poles recorded in iron rich rocks. Reversal has been dated by K/Ar • Collision of India and Eurasia= Himalayas . Inception of rifting along the east African rift valley.
Red Queen Hypothesis
• Evolutionary arms race • Must run faster and faster to remain in the same place
Primitive Traits
• Evolved long ago, found among groups only distantly related.
Derived Traits
• Evolved more recently , reflect closer evolutionary relationships.
Australopithecus Sexual Dimorphism
• Female 106-126 cm, wt 30 or 40 kg • Males 140-150 cm, wt 65-75 kg • More sexually dimorphic than ardi • Male to female ratio ranges 1.1 to 2.5, most estimates are around 1.5
Sedimentary Rocks by Particle
• Fine (small) 1.) Mudstone, shale (clay) 2.) Sand Stone ( Sand) 3.) Conglomerate ( pebbles , cobbles , boulders) • Coarse (big) 1.) Reflects energy in sedimentary environment ( to transport) • Small rocks = low energy • Large Rocks = high energy
Ardis Hand
• Fingers long • Metacarpals short • Wrist= no reinforcement for knuckle walking • Wrist can be bent back • Interpretation, orboreal palmigrady, not knuckle walking • Elbow can be fully extended • No locking mechanism like apes • Not suspensory
Fossils
• Fossils are rare • Fossilization Process limits what parts • Must have lived and died in a area • Animals must get buried without a disturbance
First Fossil Chimpanzee
• Fossils of early hominines were very chimp like • But hominines have changed a lot in 7ma • Modern time chimps found in African equator forest but no fossils • Forrest conditions are not good in preserving fossils of chimps • Rift valley of hominine site very good for preservation
How Do we Detect the Effects of Pas Climate Change?
• Geological features such as shore lines and loess • Fossils of plants such as leaves and pollen • Fossils of animals that eat plants • Isotopic content of fossil organism ( co ^2 , and o^18)
Cladistics
• Goal: to reconstruct evolutionary relationship • Method: Identify monophyletic Groups and clade • Monophyletic groups are defined on basis of shared derived traits.
Origin of Stone Tools
• Gona , Ethiopia • Stone tools ( liithic technology)→ 1.) core→ 2.) hammerstone→ flake • Flakes are sharp tools make new resources available for the first time
Take Home Message
• Habitats changeable • Both humans and chimps adaptable to their environment • Forest vs. savanna adaptation probably not reason for diversion of chimp and hominine lineages.
Ardis Foot
• Hallux( Big Toe), • Opposable for grasping
Conglomerate
• High energy deposition
Termites
• High fat , calorie, high yield
Sandstone
• Higher energy environment
Comparison of Orrorin Femur with Ape and Human
• Human like = large groove for oburator externus muscle that adducts the thigh • Non human like= long neck of femur, distal humerus- large erest for branchioradiulis muscle, which is used in walking.
Hand of Robustus
• Human thumb • Mobile • Robust • Power grip- thumb to palm and fingers • Precision grip- tip of thumb to finger tip • Thumb robust
Teeth and Dieting
• Incisors : food preparation (taking a bite) • Canines: food preparation, killing your meal, defense and display • Premolars and Molars: food processing
A forest canopy
• It is a conglomeration of trees that has many different levels. There are several different animals that have adapted to different levels of a forest canopy, just like different trees adapt to different levels of the forest canopy (smaller trees require less light, taller trees require more light). This is known as niche partitioning.
Diet of Robustus
• Jarman bell principal • Large body sizelow metabolism rate • Large quantities of low quality food • Repetitive chewing • Thick enamel • Gritty food
Miocene Ape Becoming Human
• Kenyapithecus • Reduced canine (human like) • Honing facet and diastema is chimp like
Sedimentary Environment
• Lacustrine Sedimentary Rock = deposits in a lake • Fluval Sedimentary Rock = Deposited by flowing water in a river • Eolian Sedimentary Rock = loess is a eolian sedimentary rock
Similar habitats for Orrorin and Sahelanthropus
• Lakeshore, small streams
African Miocene Fossil Ape Sites
• Large overlapping canines ( rub against each other) • Honing facet • Disastema = gap tooth row where canines rest when mouth closed.
Africanus Teeth
• Large rear teeth • Small front teeth • Canine pillars
23-5ma Miocene-origin of huminoids ( Apes) • Whats so special about apes?
• Larger body size and life span • Long time between births • Offspring helpless at birth • Upright posture • Large brain • No tail • Short muzzle • Increased reliance on vision • First appearance of Hominoids : Africa Europe Asia ( land bridge was at 17ma)
Criteria for Genus Homo
• Larger brain • Human like teeth • Human like body proportions • Larger body in size • Human life history • Possibility of tool use and carnivory
Macroevolution
• Larger changes ( appearance new species , extinction) • Longer period of time • More difficult to observe directly ( E.g origin of species, extinction)
Human Teeth
• Like frugivores and omnivores • Large incisors • Bunodont molars and premolars • Small canines
Systematic
• Linnaean system shows overall similarity • Charles Darwin species are similar due to common ancestor • Willi Hennig classification should reflect phyogeny (evolutionary , relationships) names due matter
Roots
• Low calorie, high fiber and high yield
First Fossil Chimpanzee
• Low crown bunodont molar • Cusp pattern like pan • Thin enamel • Chimpanzee incisor: very thick at base, lingual tubercle, thin enamel • Habitats changeable • Habitat of common ancestor isn't known yet • Both homins and chimps are adaptable • Forest v savanna may have been reason why diverged
Miocene Apes , Early Primates
• Lower primates= prosimians 1.) Lemurs 2.) Torsiers " Lower vs Higher debate" 3.) Lorises • Earliest primates resemble the lower primates • Haplorhines CatarrhiniHominoideaHominidaeHomininae=humans and extinct bipeds • Early mammals lived at the same time as the dinosaur (200ma) . Most early mammals were very small • Repenomamus robustus ate dinosaurs . We know this because dinosaur remains were found in the gut. • K/T Boundary ( Cretaceous- Tertiory) 65 ma( May have been asteroid impact, extinction of the dinosaurs) . Before the K/T very few distinct group of mammals . After K/T boundary mammals became much more diverse (adaptive radiation) • Earliest primate fossils was at 55ma. Bob martin believes primates are much older. Fads and lads, first and last appearance data. How likely it is that you will find the very first or very last member of a species. • Modern strepirhines ( Eocene era) had lemurs and lorises • Adapis (54 ma Eocene)( Early strepsirie) 1.) Primitive traits- dental formula and body weight small (less than 7kg) 2.) Derived trait - nails not claws , expanded visual cortex, reduced olefactory bulb. Adapis had stereoscopic vision
Miocene Apes , Early Primates
• Lower primates= prosimians 7.) Lemurs 8.) Torsiers " Lower vs Higher debate" 9.) Lorises • Earliest primates resemble the lower primates • Haplorhines CatarrhiniHominoideaHominidaeHomininae=humans and extinct bipeds • Early mammals lived at the same time as the dinosaur (200ma) . Most early mammals were very small • Repenomamus robustus ate dinosaurs . We know this because dinosaur remains were found in the gut. • K/T Boundary ( Cretaceous- Tertiory) 65 ma( May have been asteroid impact, extinction of the dinosaurs) . Before the K/T very few distinct group of mammals . After K/T boundary mammals became much more diverse (adaptive radiation) • Earliest primate fossils was at 55ma. Bob martin believes primates are much older. Fads and lads, first and last appearance data. How likely it is that you will find the very first or very last member of a species. • Modern strepirhines ( Eocene era) had lemurs and lorises • Adapis (54 ma Eocene)( Early strepsirie) 5.) Primitive traits- dental formula and body weight small (less than 7kg) 6.) Derived trait - nails not claws , expanded visual cortex, reduced olefactory bulb. Adapis had stereoscopic vision
Pyroclastric Flow
• MT Vesuvius Pompeii 79 AD • Cloud of ash and gas • Saturated with water • Column collapses under own weight • Plaster cast of people buried by pyroclastic flow
Types of Volcanic Rock
• Magma = underground • Lava = extruded at surface • Ash = Exploded in Air
African Miocene Hominoids
• Many genera and species unlike now • Diet and locomotion diverse • Quadrupedal and suspensory • Mostly fruit eating • Body size 20-50kg • Sexually diamorphic • No certainty which is ancestral to humans
Neutral Mutation Effect
• Many mutations are silent , neutral • No apparent effect on organism
Charles Darwin ( 1809-1882)
• Mechanism of evolution is natural selection or different reproduction • It requires variation
Site in Germany (IDA) (47ma)
• Messed shale quarry, Germany • Ancient lake beds with volcanic ash • Age of death 9 months old ( early primate Ida may have drowned in lake) • Two feet tall • Partially broken wrist that started to heal • Body outlined and impressions of fur is preserved in lake mud • Had opposable thumbs and big toe • Ida= darwininius • Remains of last meal ( fruit and leaves) is in stomach cavity
Living floor of OH
• Microscopic traces of usewear on tool edges • Different tasks • Stone tools show microscopic edges • Bones show cutmarks made by stone tools • Cutmarks on bone ends show carcasses were disarticulated • Cutmarks on bone shaft show where meat was removed • Bones were cracked open with hammerstone to remove marrow • Early interpretations stressed similarity to modern foraging people
Fossils
• Mineralized remains of animal or plant ( Usually bones or teeth) • Trace Fossil= sign of animal or plant interaction with its environment • Artifact= any object made or modified by hominines
Australopithecus Skull
• Moderately prognathic brain size (400-500cc) • Reduced canine size • Large cheek teeth, thick enamel, massive jaws and supporting muscles vertical midface
"An Essay on the Principle of Population" 1798 - Thomas Malthus 1766 -1834
• More offspring produced than resources can support • Periodically eliminated by disease, war, famine.
Little Foot
• Most complete hominin skeleton • Excavation at little foot site is siiberg • Robert broom discovered fossils of both africanus and robustus in south Africa
Aramis Plant and Animal Fossils
• Most woodland bovids • Enclosed habitat or woodland forest
Ardi Diet
• Not exclusively frugivorous • Not particularly abrasive • Probably omnivorous • Isotopic evidence= mix diet • C3/c4 includes both, tree product (fruit, seeds) grass parts( roots , stems) • No large incisors or thin enamel of apes.
Gene Regulations
• Order that genes are activated during the life of the organism
Adaptations and evolutionary relationships of paranthropus
• Paranthropus boisei. Which of the largest molars and premolars of any hominin. Massive Mandible . Tiny incisors and canines . Large quantity of low quality food. • Has sagittal crest • Zygoma • Post orbital constriction • Temporal fossa Chewing Muscles • Temporals and Massetors • How to build a chewing machine- large molars and premolars and large muscles
What about thick enamel
• Perikymata • Teeth grows in crypts • Then erupts through jaw • Enamel formation is cyclic • Perikymata reflects daily growth cycles • Number of perikymata shows amount of time enamel is developing • Sivapithacus and austrialopithecus both have thick enamel • Sivapithacus is fast enamel secretion , short period of time • Australopithecus is slow enamel secretion and a short period of time • Sivapithecus= ramapithecus, it is an orang , siva/rama is not ancestral to humans , humans evolved in Africa • Homiodea (superfamily)(hominoid) living and extinct apes and humans • Homindae ( Family) (hominid) living african apes chimps gorillas and humans • Homininae (subfamily)
Effects of Changing Isolation in Tropics
• Precipitation- (both average and seasonal) cold dry , warm wet • Vegetation- Dry more grass, Wet more trees • Pollen , spores and diatoms are blown out to sea. Can use them to see what is growing on the land.
Chimp Genome Method
• Published in2005 • Took about 5 years
Ardi Locomotion
• Quadruped, arms and legs are the same length • Suspensory primates= long arms to swing from tree to tree • Ardis arm and lengths are the same length. Radius / tibia ratio= .95. Generalized above brunch quadruped • Bipedal humans=.7 • Long hands and feet • Lumbar spine is longer and more flexible than chimp • Bowl shaped upper pelvis-bipedal • Foramen magnum anterior- bipedal • Not a knuckle walker • Elbow not suspensory • Strong arms climber
Volcanic Ash
• Records single instant in time • Dateable by K/Ar and Ar/Ar • Each eruption has a unique composition ( Geochemical Finger print) • Can cover a huge area • Widespread Volcanic ash permits correlation over entire region
Derived Hominin Dental Structure
• Reduced Canines ( no diastema or honing facet) • Post Canine Megadontia • Large molars and premolars • Thick tooth enamel
Argon/Argon
• Refinement of K/Ar • Works on volcanic rock of any age
Dating Methods
• Relative- order of events • Absolute- age in years, amount of elapsed time, always have range of error
Low Energy
• Sedimentary environments • Better for study of fossils • Fossils less likely to be broken • Less energy= undisturbed • High energy= disturbed
Locomotion in Early Homo
• Short stocky legs • Long arms and forearms • Longer slender legs
Homology
• Similarities due to a common ancestor
Homoplasy
• Similarities due to convergent evolution
Sahelanthopus Primitive Features
• Small brain size 300 cc • Petrous portion ( ear area) of temporal bone of skull orientated like chimp • Petrous portion of temporal houses semicircular canals. Its important for the sense of balance. Quadrupeds orientated differently than bipeds • Sahelanthopus not exactly like modern bipeds
Meat Eaters ( Carnivores)
• Small incisors • Large Canines • Carnassials ( Slicing molars and premolars) • Short Gut
Leaf Eaters ( Folivores)
• Small incisors • Sharp and high crowned molars • Long gut
Mudstone (shale)
• Small particles • Low energy
Comments on Mutation and Human Gene
• Species are a breeding population • New mutations will spread throughout population • Mutations are random events • Individual mutation are so random but total genome is so large that mutation rate is effectively uniform • Human genome is 3.2 billion base pairs • Genome acts like a clock • Need fossils to set molecular clock
Adaptive Radiation
• Sudden appearance many closely related species
Relative chronology: order of events
• Superposition Nicholas Steno father of stratigraphy stenos lay=older layers are formed first, youngest at top • Correlation among sites lithostratigraphic correlation strata correlated on basis of rock type
Afarensis Environment
• Swamp, river flood plain and lake margin
Olduvai Gorge and Koobia Fora
• Tanzania • Shore of alkaline lake • Delta and small streams • Grassy woodland
Taxonomy
• Taxon: An named group in Linnaean classification (e.g. genus, species, family) • Taxa: defined by anatomical similarities. Grouped into Hierarchy
Oxygen isotopic Ratio
• Temperature and oxygen content of drinking water • Degree of animals in water stress • Mixture of fossil and grass eating and woodland • Ardi was found to be in C3 or mostly forest and woodland. • Temperature and oxygen content of drinking water • Degree of animals water stress
Sahelanthropus dervived traits from humans Experimental dating of berrillium
• Thick enamel • Large supraorbital torus • Reduced prognathism ( less like chimp and more like hominin) • Small canine • Foramen magnum • Head superior • Quadruple orientation • More anterior ( forward) position indicates bipedalism of foramen magnum • No honing facet • No canine diastema • Supra orbital torus similar to hominins ( eye brow ridges)
Homo Habilis (1813)
• Thin bones of cranial vault • High forehead • Small body size • Brain size only 510 cc • Teeth like homo but small • No sagittal crest • Flat face • Small brow ridges
Clade
• This is the same as Monophyletic Group, but including the common ancestor, which may not be known
Ramapithecus Brevirostrus
• Though many years to be human ancestor, it isn't • Supposed hominin features 1.) Parabolic dental arcade ( not a good trait) 2.) Thick tooth enamel
Ramapithecus Brevirostrus
• Though many years to be human ancestor, it isn't • Supposed hominin features 5.) Parabolic dental arcade ( not a good trait) 6.) Thick tooth enamel
Human Genome Project
• Took 13 yrs to complete • 2000 sketch published • 2001 was completed version
Cladistics : How is it different?
• Traditional methods examine overall similarity among organisms • Cladistics look at characters • Hennig realized that some characters are better than others for constructing evolutionary relationships.
Environment of Africa
• Tufa sediment= fresh water spring • Geology for river , lake are only there for a short time period so that is why the chimps were in the savanna. • Evidence of forest from colobus monkey because they were leaf eaters • A lot of contradicting evidence from animal fossils of what habitat was there • Gallery forest was confined around a stream • Chimps favorite food is ripe fruit that's why they are in the forest • Early chimps were found in different environments such as wooded and open
Ardi Pelvis
• Twisted ilium (human like) • Tall lower pelvis (Chimp like) • Chimp pelvis is tall and narrow and the pelvis is flexed • Human pelvis is short and broad and the pelvis is extended
Autapomerphy
• Unique Trait
Radiocarbon (14^C)
• Used on organic materials • Clock set when organism dies • Dates things younger than 40ka
Potassium / Argon=K/Ar
• Used on volcanic rocks • Clock set at time of eruption • Works on rocks older than 200ka
Shared Derived Traits
• Used to define monophyletic groups, clades. ( jaws, lungs, claws , nails, feathers , mammory glands)
Cladisitic Analysis Genetic Data
• Uses many characters • Very useful in showing evolutionary relationships • Conclusion sometimes different from those derived from anatomy
Types of Rocks
• Volcanic Rocks= derived from molten crust • Sedimentary Rocks = composed of particles of another rock • Metamorphic Rock = Sedimentary rock transformed by heat or pressure
Size of the Particle Transported
• Volume of water • Speed of flow • Influenced by slope
Charles Darwin observations
• Voyage of the Beagle 1831 • Darwins Observation #1 -Extinct Animals (Fossils) Resemble Living Ones In Same Region • Darwins #2 observation - Birds Similar, But Different Types on Different Islands. Overall similarity is a common ancestor. Differences were in the beaks of the birds and plumage. The birds adapted to the local conditions.
Alfred Russell Wallace (1823-1913)
• Wallace Independently came up with idea of evolution in 1856: Read Malthus, realised: • Checks on human population growth (war, famine, disease) also apply to animals. • 2. Variety in Nature is affected by this process. • 3. Can account for change through time!
Paranthropus (KWT 17000)
• West turkana, Kenya • Called aethiopicus • Earliest and most primitive form • Small brain • Very prognathic • Very large rear teeth • Flaring zygoma • Complex sagittal
Context of Artifact or Fossil
• Where found? • How old? • How Buried? • Circumstances of life (environment) • Gives meaning to artifact or fossil • How did this object get home? • Context = geology
Polarity
• Which is primitive and which is derived
Biostratiographic correlation
• Work out local sequence and fossils they contain • Figure of order of fossils throughout time
Chimp Teeth
• low crowned (bunodont) • cusp pattern like chimp • thin enamel different than human • Chimp incisors were very thick at the base • Chimp incisors had lingual tubercle ( bump on incisor) • Chimp Incisor had a thin enamel and short roots
Hutton & "Uniformitarianism" (Actualism)
•"Present Is Key To Past" •Processes observed today, operating over long periods of time, •Can produce geological features observed in modern world.
Devil's Tower, Gibralter Neanderthal child
•Age at death from state of brain & facial development: 5-6 years •Age at death from teeth & perikymata: •3 years •Accelerated brain growth •"Sped up"life history: •Shorter childhood •Early maturity •Shorter lifespan •Differencespresent early in life
Cuvier & "Catastrophism"
•How explain fossils? •Successive Groups of Fossils •Periodic Extinctions & Creations (Catastrophes) ("Antediluvian" = Before the flood)
Neanderthal DNA
•Indicatestheyare genetically programmed. •Neanderthal type specimen preservedancient mtDNA •Identified Neanderthal derived traits. •Finding: No Neanderthal derived mtDNA traits present in modern humans. •(Ovchinnikovof UConn: Same finding for Neanderthal from Mesmaiskaya Cave, Rep. Georgia.) •Now: 8 Neanderthals sequenced. •Same finding. Svante Pääbo Max Planck Institute, Leipzig
Neanderthals: Like Us or Not Like Us?
•Large Brain •Effective Technology •Effective Hunting •Use of Fire •Burial of Dead? •Language?a •Genetic Differences •Anatomical Differences •Retained Primitive Traits •Cold Adaptations •High Activity Levels •Broken Bones •Interpersonal Violence? •Cannibalism
Montesquieu (1689-1755)
•One species can give rise to another. •Number of species increases through time.
Neanderthal Limb bones
•Robust Bones •Bowed Shafts •Expanded Joint Surfaces •Pronounced Muscle Markings •Reflects High Activity Levels
