Week 5: Fossil Evidence

MILEs

multiple lines of evidence

• evolution: descent with change

• anatomy: fossils, comparative anatomy

• artefacts: tools

• genetics / molecular evidence: DNA

Fossil formation steps

1. death

2. desposition

3. permineralisation

4. exposure

relative dating

compare to similar material of known age

numerical dating

isotope analysis, thermo-luminescence (trapped electron count), molecular clock

hominin

taxonomic tribe of the subfamily homininae, comprise of 2 extant groups: Homo and Pan

• chimpanzees (Pan troglodytes) and bonobos (Pan paniscus).

Cradle of Humankind

South Africa

Olduvai Gorge

Tanzania, Homo habilisa

Koobi Fora

Kenya, paranthropus aethiopicus

hominin key features

• first appear in fossil records 6 MYA

• bipedalism

• thicker enamel, reduced canines, larger molars

Sahelanthropus tchadensis

• possibly earliest hominin

• 7 MYA

• “Toumai”

• 320-350cc

Australopithecus afarensis

• “Lucy”

• Hadar, Ethiopia

• over 40% recovered

• 3.2 MYA

• 450cc

• first bipedalism

Australopithecus africanus

• “Taung child”

• 2.3 MYA

• Taung, South Africa

• 3 years old, bipedalism

• 440cc

Homo habilis

• 2.2 MYA

• stone tools

• dental / femur development suggestive of childhood stage

• 500-600cc

Homo erectus

• “Turkana boy”

• 1.6 MYA

• 9-12 years old on teeth/growth plates

• 900cc

• females smaller than males

• no adolescence

• left Africa and existed for nearly 2 MY

Homo antecessor

• Gran Dolina, Atapuerca, Spain

• discovered by JM Bermudez de Castro

• may have adolescence

• 780,000 YA

• may be common ancestor to modern humans / Neanderthals

• 1000cc

Denisovans

• 300k - 50k years ago

• Siberia, Russia

Paranthropus aethiopicus

• “The Black Skull”

• Lake Turkana

• 2.5 MYA

• bipedal

• robust craniodental anatomy (sagittal crest)

• enormous molars, large lower jaw

Homo Neanderthalensis

• 400k-40k YA

• 1500cc

• sophisticated tools, control fire, shelters, clothing

• hunted large animals

• buried dead, ornamental objects

Homo sapiens

• 1200 - 1600cc, average of 1350cc

• new fossils of modern humans dated 300k YA at Jebel Irhoud, Morocco

• fossil teeth Lida Ajer, Indonesia dated 73-63k YA

Homo floresiensis

• found in Flores, Indonesia

• 100,000 - 50,000 years ago

Homo naledi

• Rising star cave, South Africa

• 450-610cc

• 236-335k YA