Homo Erectus Lecture 12 Flashcards
Which hominin was the first to expand outside of Africa?
Homo erectus.
How does H. erectus differ to both H. rudolfensis and H. habilis generally?
Larger brain size and body size!
Also, more complex tools (Acheulean technology)
Where does the name Acheulean come from?
The Acheul site in France where the tools were first discovered.
Describe H. erectus
1) Increase in brain and body size but large variation (body and size has increased so EQ hasn’t changed that much)
2) More modern body proportions
3) Wider diet that Australopiths
4) More sophistcated technology (Acheulean)
5) Wider geographic and climatic range
6) Terrestrial species
Where can H. georgicus be found?
It was found in Georgia in Europe. Now it is largely referred to as H. ergaster georgicus.
Where can H. erectus be found?
In Asia
Where can H. ergaster be found?
In Africa
Who first discovered Homo erectus?
Eugene Dubois, a Dutch scholar who was taken by Darwin’s idea of evolution and had read about Haeckel looking for a missing link between humans and other apes.
What is the holotype of H. erectus?
Trinil 2, discovered by Eugene Dubois 1890-1892
Cranium
The brain of this holotype was too big to belong to an ape that wasn’t a human
What did the femur that Dubois found show about H. erectus?
That the individual was walking on two legs.
Also, this femur showed the specimen was diseased (due to boney growth).
Describe Peking man.
Originally named Sinanthropus pekinensis but later labelled as Homo erectus.
Describe the apomorphies of Homo erectus sensu lato.
1) Larger brain than previous hominins, however, study of 1 year old infant indicates ape-like development and short period of postnatal cranial growth
2) Well developed Broca’s cap (not just language but precision movements)
3) Thick cranial bones
4) Flattened cranial vaults with receding forehead
5) Thick and almost continuous brow ridge
Describe the plesiomorphies of Homo erectus sensu lato (ancestral traits)
1) Facial prognathism
2) Relatively large molars
3) Absense of a chin
Describe traits of Homo erectus sensu lato in respect to later homo.
1) Occipital is strongly angled.
2) Small mastoid process, medially inclined, however, unlike later humans it projects below cranial base
3) Squamosal suture runs relatively straight from frontal to occipital bones but in later humans it arches upwards.
Which features make the Asian specimens of H. erectus distinctive?
Sagittal keel
Thick cranial vault
What is another name for African Homo erectus?
Homo ergaster! Usually, people use this.
Describe the features that African H. erectus/ergaster share with the Asian erectus.
1) Post-orbital constriction
2) Supraorbital torus and sulcus pronounced
3) Pronounced occipital torus
4) Small postcanine dentition
5) Forward projection of nasal aperture
Describe the H. ergaster cranial characteristics.
1) No sagittal keel
2) Tori are thinner (brow ridge)
3) Smaller, more gracile face
What is Turkana boy?
An almost fully complete (85%) H. ergaster specimen (12 year -approx- old boy)
1.6mya
KNM WT 15000
List the autapomorphies of Turkana boy.
1) Large body size (average body height 1.70m and average weight 58kg).
2) Longer legs in respect to arms (even more so than in modern humans). Could be adaptation to to endurance running.
3) Less protruding abdomen –> smaller gut
Describe the plesiomorphies of Homo ergaster.
1) Relatively long femoral neck, small vertebral bodies, 6 lumbar vertebrae
2) Vertebral canal narrower than in modern humans, especially neck and thorax.
Why is the Turkana boy a difficult specimen to understand H. ergaster?
He was still in development, so it doesn’t show what a fully grown adult would look like!
What was found at site Fwji14E in Ileret, Kenya?
Hominin footprints. The footprints are consistent with the stature and body mass of Homo ergaster/erectus
Describe the footprints of Homo ergaster found in Kenya.
Found in sedimentary layers dated to 1.51-1.53 mya.
1) Adducted hallux
2) Medial longitudinal arch
3) Medial weight transfer before push off
Essentially a modern human goot function and style of bipedal locomotion
Why was it thought that secondary altiriciality started with Homo erectus?
Prediction of how the mature female pelvis would have looked like suggested that the narrow birth canal would have not allowed the birth of a baby with the brain size expected considering the increase brain of H. erectus adult
Based on pelvis of Turkana boy
What changed people’s minds on the altriciality of H. erectus? What made them think there was less altriciality in the species?
The discovery of the Gona pelvis in 2008 revealed that the birth canal would have allowed the passage of a baby skull 30% bigger than previously estimated. So H. erectus wasn’t as altricial as modern humans.
