BIO1300 – The Human Animal
The Human Timescale
BIO1300 – The Human Animal
Geological Timescale
Millions of Years
Periods Permian Triassic Jurassic Cretaceous Tertiary Quat. Major events
Dinosaurs Development and Human Evolve and Expand Diversification of Evolution Start of Abundance of Flowering Age of Age of Large Herbivore Plants Mammals Reptiles Dinosaurs
BIO1300 – The Human Animal
1 Species
● A population or group of populations that are capable of interbreeding and that can produce viable and fertile offspring
Mule
BIO1300 – The Human Animal
Primate Ancestor
● Pen-tailed tree shrew ● Ecologically similar to squirrels ● Tree-dwellers among branches ● Eats fruit and insects Ptilocercus
BIO1300 – The Human Animal
Primate Evolution
New World Old World Lemurs Pottos monkeys monkeys Gibbons Orangutans Gorillas Chimpanzees Humans
6 million years ago
at least 65 million years ago Ancestral arboreal insectivore
BIO1300 – The Human Animal
2 Primate Evolution
● Primates : – Primitive, smaller bodies and brains: Prosimians • Lemurs and Tarsiers – Large bodies and brains: Simians/Anthropoids
BIO1300 – The Human Animal
Primate Phylogeny
Hominins
Hominids
Anthropoids
Prosimians
BIO1300 – The Human Animal
Prosimians and Monkeys
Marmosets Tamarins Capuchins Howler Spider
Guenon Macaque Baboon Mandrill Langur Proboscis
BIO1300 – The Human Animal
3 Family Hominidae: The Great Apes
BIO1300 – The Human Animal
Hominins
BIO1300 – The Human Animal
Our Common Ancestor
● Probably had many traits in common with modern Chimps and Bonobos – Diet of fruit – Lived in mixed-habitats – Used tools – Hunted small animals/ insects – Culture (Transmission of non-genetic traits)
BIO1300 – The Human Animal
4 Evolution of Brachiation
● Efficient way of moving around branches ● Accompanied by greater dexterity and diversity of uses of arms and hands
BIO1300 – The Human Animal
Evolution of the Primate Hand
BIO1300 – The Human Animal
Primate Hands and Feet ● Opposable thumbs and big toe ● Fingers and toes Red-ruffed Lemur have flat nails – Exception: toilet claw
Galago
BIO1300 – The Human Animal
5 Primate Characteristics ● Reduced snout – Increased visual acuity instead ● Reduced number of teeth but increased diversity (heterodonty) – Incisors to shear – Canines to slice – Pre-molars to crush – Molars to grind
BIO1300 – The Human Animal
Primate Vision
● Eyes facing forward – Binocular vision – Depth-perception and 3-D – Well-developed occipital lobe
BIO1300 – The Human Animal
Binocular Vision
BIO1300 – The Human Animal
6 Reduced Reproductive Rate
● Carrying offspring in trees ● Emphasis on care and learning
BIO1300 – The Human Animal
Evolution of Bipedalism
BIO1300 – The Human Animal
Human Lineages
6 million 5 million 4 million 3 million 2 million 1 million Present
Homo sapiens Paranthropus boisei
Australopithecus afarensis
Paranthropus robustus
Ardipithecus ramidus Australopithecus africanus Homo neanderthalensis
Australopithecus anamensis
Homo erectus
Paranthropus aethiopicus Homo ergaster
Homo habilis
Homo heidelbergensis
BIO1300 – The Human Animal
7 Sub-Fam Homininae (7MYA) ● Sahelanthropus tchadensis ● Chad, Africa 7-6 MYA ● Size of a chimp ● Probably bipedal – Ventral position of foramen magnum Brain = 320-380 cc
BIO1300 – The Human Animal
Hominins
● Orrorin tugenensis ● Kenya, Africa (6.2-5.6 MYA) ● 20 specimen found ● Not sure if direct human ancestor or side branch ● Bipedal femur ● Long fingers (arboreal) ● Frugivorous or granivorous teeth
BIO1300 – The Human Animal
Hominins ● Ardipithicus ramidus ● Ethiopia, Africa (4.5-4.3 MYA) ● First complete skeleton (female) ● Brachiating hands and arms ● Opposable toe 300-370 cc but flat foot adapted for walking
BIO1300 – The Human Animal
8 Hominins
● Australopithecus afarensis 1.51m (1973) 1.05 m ● Tanzania, Ethiopia, Kenya (3.7-3 MYA) ● Hundreds of skeletons found ● Fully bipedal but also arboreal ● Pronounced sexual dimorphism Tracks found in volcanic ash 380-550cc
BIO1300 – The Human Animal
Hominins Paranthropus bosei ● Paranthropus (3 species) ● Ethiopia, Kenya, Tanzania ● 2.7-1.3 MYA ● Lived in humid habitats
● Sexual dimorphism 474-545 cc ● Principally bipedal
● Broad teeth, large sagittal Male: Female crest 1.37 m 1.24 m 49 kg 34 kg – Tough, herbivorous diet ● Used stone tools
BIO1300 – The Human Animal
Homo ● Smaller faces, jaw not prognathous ● Smaller molars but bigger incisors and canines ● Bigger brains ● Thorax and pelvis upright and slender ● Longer legs ● Shorter toes ● Culture
BIO1300 – The Human Animal
9 Questions?
BIO1300 – The Human Animal
10