Exam (elaborations)
ARCH 131 (HUMAN ORIGIN) FINAL EXAM NOTES SIMON FRASER UNIVERSITY.
- Course
- Institution
ARCH 131 (HUMAN ORIGIN) FINAL EXAM NOTES SIMON FRASER UNIVERSITY.
[Show more]
Content preview
ARCH 131 (HUMAN ORIGIN)FINAL EXAM NOTES SIMON FRASER
UNIVERSITY.
,Unit 6 CONTINUATION
Paranthropus (Australopithecus?) aesthetics
• Aka “Black Skull”
o Stained kind of black by some kind of mineral
o 2.5 million yr old
o Flaring cheek bone (make face kind of flat), large molars, sagittal crest
▪ Bone that make up mouth super thick/strong
• Highly developed chewing apparatus
Masticatory Apparatus
- Temporalis muscle (underneath cheek to skull) & Masseter muscle (cheekbone area)
o Two muscle provide bite power
o Bite force: Human – 150psi / Gorilla – 1300psi (example)
▪ Gorilla need strong so the Temporalis muscle goes up to skull edge
(human ends at centre area of skull)
• Sagittal crest is an anchor at the top
- Seeing this development with specialized chewing
o Seeing little from africanus; aethiopicus = more dramatic
▪ Like gorilla description
- Aethiopicus direct linage to Paranthropus species; robustus & boisei
bosei
- East Africa (also afarensis)
- 2.3 to 1.3 mil yrs ago
- Zinj (some skull) discovered in 1959
o Important in human origin research
o Indicated the place Liki (liki tiki I think) was the place to look for early
hominal ancestors
o Spurred on discovery of other fossils
- About same size than afarensis and africanus
o Still small hominin
o 120cm F / 140cm M
- Prominent canine pillars (not as prom as chimpanzee but more than africanus
- Brain size = 500-550 cubic cm
o Increase in cephalization (brain size to body size)
- Massive jaw, robust
o Further increase in canine, but small like ours
o Further increase in molar (bigger than aethiopicus)
- Nickname “Nutcracker Man”
o Powerful jaws/cracking nuts
robustus
- Slight more recent 2-2.1 mil yrs ago
- Similar size, little difference with bosei and small bodied hominins
, - Prominent canine pillars, remains of sagittal crest, flaring cheek bone, big molars, big
bony structure in mouth
o Increase in chewing apparatus
- 530 cubic cm for brain
- Brain not just larger, but components of brain that related to abstract thinking increase
- Sig. change like bosei; increase in chewing apparatus
o Big molars, small front teeth, huge robust mandible, big flaring cheekbone,
sagittal crest
robustus and bosei (also aethiopicus)
- Both increase in chewing apparatus (most sig.)
- Megadontia = “huge teeth”
o Massive molars, front teeth small
- Designed to chew hard/poor quality plant food
o Roots, tubers, inner bark, gorilla food, fibre
- Haven’t found any descendent fossils
o Seen to be extinct around 1 mil ago
▪ Dead end of branch
▪ Starting from africanus
o Specialized species, did well for a few mil years but died due to change
▪ Eg. Drier environ. (was major climate change)
▪ Classic examples (bosei robusto)
o Evolutionary branch highly specialized in diet
- Specialized species, classic ex.
▪ Very specialized food resource, environments, climate
▪ Hard to adapt when circumstance change
▪ Can go extinct
- Generalists/generalized species: not particularly adapted to any environ. Resource
▪ Kind of wide range of environments (sort of like us)
▪ Always under lil selective stress
▪ Can go extinct but tend to do better since not super attached to one
thing
Unit 7: Emergence of the Genus Homo
Possible origins of our genus Homo?
- Many see afarensis as our homo lineage
o Not 100 but most likely, since no better candidate
o Others too specialized
- Two earliest we see “guess” see in our tree
o habilis and rudolfensis
▪ for moment we see as two separate species
Homo habilis
, - 2.8-1.5 mil yr ago
o Almost as old as recent afarensis fossils
- Most in East Africa (maybe some in South Africa)
- Aka “Handy Man”
- best candidate for stone tool maker
o but have some potential for older stone tool makers
o Tools got some cut marks (left on bone to butcher animal to eat)
o Not everyone agree
▪ Some species using stone tools as early as 3.4 mya
• Predate homo fossils
• Maybe afarensis
• Both bosei and robustus (little later than this) also use stone
tools
o Found a few in South Africa
- Holotype or “Type Fossils”
o people fnd new fossil, they analyze/study, decide that it is something new
(new species genus)
o Become “holotype” for that species
▪ Reference for that species
o Some broken fossil
▪ Considered early homo species
▪ No nice complete homo habilis
- Still small bodied
- Dk sexual dimorphism (can’t tell F from M)
o Early hominins easier, from teeth
- 130cm
- Brain size (increase)
- Reduction in molars
- Intermembral Index: body proportion
o Arm length/leg length * 100
o Over 100 = arm longer than leg
o Less = arm shorter than leg
- Lower Intermembral index
o Potential in our lineage
- KNM
o Cranial capacity 510 cc (cubic cm)
o Not super big
- “Twiggy” skull
o 590 cc
- Found some up to 700 cc
- Avg brain size bigger than early hominins
- Mandibles
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller saraciousstuvia. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $17.09. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67096 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now