Definitions Hominin – term that refers to humans and their extinct erect-walking ancestors. They belong to the tribe homini. Hominin – term that refers to humans and their extinct erect-walking ancestors. They belong to the tribe homini. Sometimes the word ‘hominid’ is used instead of hominin but this term refers to outdated classification so hominin is the preferred term. Sometimes the word ‘hominid’ is used instead of hominin but this term refers to outdated classification so hominin is the preferred term. Hominoid – term that refers to any member of the superfamily ‘hominoidae’ Hominoid – term that refers to any member of the superfamily ‘hominoidae’ Humans are both hominins and hominoids Humans are both hominins and hominoids

Classification of Humans Animal Chordata (vertebrates) Mammalia Aves Eutheria (placental) MarsupialiaMonotremes Primates Chiroptera Kingdom Phylum Class Sub-Class Order

Primates Primate – name of a taxonomic group to which humans, monkeys and apes belong. They have certain features in common: Primate – name of a taxonomic group to which humans, monkeys and apes belong. They have certain features in common: Five digits on hands and feet that can curl/bend around objects Five digits on hands and feet that can curl/bend around objects Thumbs are ‘opposable’ meaning that they can be brought into contact with other digits Thumbs are ‘opposable’ meaning that they can be brought into contact with other digits Flat nails on their digits with tips of their digits used for sensing touch Flat nails on their digits with tips of their digits used for sensing touch

Primate features 5 Digits Opposable Thumb Flat nails

Classification of Humans Primates Anthropoidea Prosimii Hominoidae CercopithecoidaCeboidea Hominidae Hylobatidae Homininae GorillinaePonginae Hominini Panini Order Sub-order Super-family Family Sub-family Tribe Genus Homo Pan

Evolution of Primates 5 MYR 7 MYR 15 MYR 17 MYR 30 MYR40 MYR Classificatio n reflects the predicted evolutionary history

Hominidae skulls From left to right: The skulls of a Gorrilla, Chimp, Orang-utan, and a common ancestor to humans and chimps

Hominins Humans are the only living members of the tribe ‘homini’ Humans are the only living members of the tribe ‘homini’ Hominins are distinguished from other members of the family hominidae because they are able to walk upright (bi-pedalism) Hominins are distinguished from other members of the family hominidae because they are able to walk upright (bi-pedalism)

The foramen magnum 1. Chimpanzee 2. Australopithecus africanus 3. Homo erectus 4. Homo sapiens

The foramen magnum

Hominin Pelvis Structure

Hominin Evolution Hominins

Hominin Evolution Oldest fossils found in Africa – hominins originated in Africa Oldest fossils found in Africa – hominins originated in Africa Earliest evidence of hominins are 6 million years old Earliest evidence of hominins are 6 million years old No evidence for genus Homo before 2.4 million years ago No evidence for genus Homo before 2.4 million years ago

Hominin Evolution Several different hominin species existed over certain time-frames for reasonably lengthy periods suggesting: Several different hominin species existed over certain time-frames for reasonably lengthy periods suggesting: Different niches occupied Different niches occupied Probably did not compete for food Probably did not compete for food Possibly were able to interbreed for some of the time Possibly were able to interbreed for some of the time Eventually some of the co-existing species may have begun to compete for food and/or habitat, leading to the extinction of some species Eventually some of the co-existing species may have begun to compete for food and/or habitat, leading to the extinction of some species

The genus Australopithecus Small- brained Small- brained Large-toothed and large protruding jaws Large-toothed and large protruding jaws Walked upright – bi-pedal Walked upright – bi-pedal Two types: Two types: Graciles (slender) Graciles (slender) Robusts (heavy build) – now separate genus Paranthropus Robusts (heavy build) – now separate genus Paranthropus The graciles are possibly ancestral to the human line The graciles are possibly ancestral to the human line Tool use limited – evidence has been found which suggests they may have used rocks to kill other animals and break bones to extract marrow Tool use limited – evidence has been found which suggests they may have used rocks to kill other animals and break bones to extract marrow

The genus Australopithecus Sexual dimorphism- differences in body structure and specifically body mass of adult males and females Sexual dimorphism- differences in body structure and specifically body mass of adult males and females Zygomatic arches (cheekbones) – more pronounced – probably large cheek muscles for chewing suggests high fibrous content in diet Zygomatic arches (cheekbones) – more pronounced – probably large cheek muscles for chewing suggests high fibrous content in diet Larger waistline – longer digestive tract due to herbivorous diet Larger waistline – longer digestive tract due to herbivorous diet Habitats can be inferred from fossil evidence – varied amongst species – again suggesting different niches Habitats can be inferred from fossil evidence – varied amongst species – again suggesting different niches

The genus Homo Evidence found of more complex tools being made and used Evidence found of more complex tools being made and used Diet changed – Diet changed – smaller teeth smaller teeth fossil evidence of animal remains near human fossils fossil evidence of animal remains near human fossils larger brain size larger brain size change in rib-cage size and shape change in rib-cage size and shape Suggests that meat became part of the diet

Australopithecus Vs. Homo

The genus Homo Compared to Australopithecus species Homo species have: Compared to Australopithecus species Homo species have: Larger brains (larger cranium size): Larger brains (larger cranium size): A. aferensis had a brain size of ~ mL A. aferensis had a brain size of ~ mL H. habilis had a brain size of ~ mL H. habilis had a brain size of ~ mL H. sapiens has a brain size of ~ mL H. sapiens has a brain size of ~ mL Smaller teeth Smaller teeth Larger skull – increased height and width, straight forehead instead of sloping like the ancestral skulls Larger skull – increased height and width, straight forehead instead of sloping like the ancestral skulls Smaller brow-ridge Smaller brow-ridge

Homo Erectus H. erectus probably evolved from H.habilis or H.ergaster around 2 million years ago H. erectus probably evolved from H.habilis or H.ergaster around 2 million years ago First hominin fossils to be found on continents other than Africa - emigrants First hominin fossils to be found on continents other than Africa - emigrants

Homo heidelbergensis Considered to be an intermediary or transitional form between Homo erectus and Homo sapiens Fossils are dated between 400,000 to as recent as 40,000 years ago Located in Africa, Asia and Europe

Homo neanderthalensis Strongly built Evidence has been found to suggest that they: Made sophisticated tools Built shelters Sometimes buried their dead Made clothing from animal skins Fossils date between 150,000 to 35,000 years ago

Homo neanderthalensis Existence overlaps with the earliest Homo sapiens Therefore not likely to be an ancestor but a cousin of the modern human Neanderthals are thought to have become extinct through competition with H. sapiens or disease

Homo Sapiens Earliest H. sapiens existed in Africa around 130,000 years ago Thought to have migrated North to Asia and Europe Probably the first human species to use complex speech

Cro-Magnon Man Considered to be a ‘modern’ H. sapiens Produced art in caves depicting hunting Found in regions of France and Spain Produced very sophisticated tools such as needles, fish hooks, chisels etc. Tools and figurines made of bone have been found Buried their dead with objects such as figurines and necklaces

Cro-Magnon Cave Art

1.HOMO HABILIS ~ LIVED: 2.4 to 1.6 million years ago HABITAT: Tropical Africa DIET: Omnivorous – nuts, seeds, tubers, fruits, some meat BEHAVIOUR: inquisitive, tool makers, cooperative 2.HOMO SAPIEN ~ LIVED: 200,000 years ago to present HABITAT: All DIET: Omnivorous - meat, vegetables, tubers, nuts, complex foods BEHAVIOUR: complex 3.HOMO FLORESIENSIS ~ LIVED: 95,000 to 13,000 years ago HABITAT: Flores, Indonesia (tropical). Not a direct ancestor 4.HOMO ERECTUS ~ LIVED: 1.8 million years to 100,000 years ago HABITAT: Tropical to temperate - Africa, Asia, Europe DIET: Omnivorous - meat, tubers, fruits, nuts BEHAVIOUR: migrated, social relationships, used fire 5.PARANTHROPUS BOISEI ~ LIVED: 2.3 to 1.4 million years ago HABITAT: Tropical Africa DIET: Omnivorous - nuts, seeds, leaves, tubers, fruits, maybe some meat Not a direct ancestor 6.HOMO HEIDELBERGENSIS ~ LIVED: 700,000 to 300,000 years ago HABITAT: Temperate and tropical, Africa and Europe DIET: Omnivorous - meat, vegetables, tubers, nuts BEHAVIOUR: creative/imaginitive 7.HOMO NEANDERTHALENSIS ~ LIVED: 250,000 to 30,000 years ago HABITAT: Europe and Western Asia DIET: Relied heavily on meat, such as bison, deer and musk ox BEHAVIOUR: tough, stoic, used animal skins for warmth

Comparing H. erectus, H. heidelbergensis & H. sapiens FeatureH. erectusH. heidelbergensisH. sapiens Prominent brow ridges ++- Rounded skull --+ Big teeth ++- Sloping forehead ++- Large Brain (1200mL +) -++ Small Face --+ Pointed Chin --+

Differing Hypotheses for the Human Evolution Story Out-of-Africa: Modern humans originated in Africa and then migrated to other continents where they competed with and out-lived more primitive populations Regional continuity hypothesis: Modern humans evolved in different regions from existing H. erectus populations in each region

Early Human Migrations based on mtDNA haplogroups

Differences in modern human populations Differences in modern human populations result from: Biological evolution through natural selection resulting in physical, biochemical and behavioural differences between populations (driven by adaptations which are genetically determined) Cultural evolution – changes in human society – passed on to people that are not genetically related Technological evolution – expressed through production and use of tools

Questions to complete All Quickcheck Biochallenge Page 617 (need internet access) Chapter Review: 2, 3, 4, 5, 7, 8, 9