Hominid studies Flashcards
List three scientific fields that provide evidence for hominid studies
in fossilised remains,
genetic evidence (especially mitochondrial DNA passed only
through mother’s line) and archaeology
Why is the classification of
hominids remain a matter of scientific debate
because of recent genetic evidence some believe that that homo eructs evovled into homo sapien and homo Neanderthals but after the mapping of the genome of Neanderthals they realized that homo sapiens and homo neanderthals havent evolved from the same group but might aswell be the same but due to the Neanderthal Dna used wasn’t complete therefore the classification remains a debate
What are the features that are used to identify whether an organism is bipedal or not
1- The position of the foramen magnum (towards the centre of skull)
2- Shape of the spine (s shaped)- greater flexibilty and support of body above legs
3- pelvis (short wide, support abdomen above legs)
4- parallel toes
5- Larger, more developed brains
6-Change in the shape of the jaw and teeth( becoming omnivorous)
How does the Position of the foramen magnum show changes in that characterize humans
The foramen magnum of humans is situated ventrally under the skull with the vertebral column underneath the skull- allows skeleton to move upright
Apes- have the FM- at the back of the skull and the articulation with the neck vertebrae is at the back of the head
what are the difference in the motion of apes and humans
Humans walk upright on two limbs so that their hands are free while walking- they are fully bipedal, humans have shorter arms and longer legs and their feet are very different from their hands, they do not have an opposable big toe and all toes lie parallel to each other to support the weight of the body in an upright position
Apes- walk on all four limbs, they move above ground using well developed forelimbs which are longer their hind limbs
How does the Shape of the spine charcterize humans and apess
Apes- Spine of apes is C shaped allows it to support the weight of the abdomen hanging below it
Humans- S shaped which provides grater flexibility and support of the body above the legs
Shape of the pelvis
Humans- shorter, wider allows for weight distribution
Apes- longer and narrower
Big toe
humans- non divergent bug toes is present when walking upright
Apes- Divergent big toe allows climbing
Brain development
Humans- larger more developed brains allowed species to develop language as a form of communication and for distinct culture. Since the organism is walking upright the hands become more skilled to make tools and manipulate fire
Change in the shape of the jaw and teeth
enabled hominids to survive in variety of habitats
How is the sequence of evolution is proposed
the fossil evidence of various of humans ancestors (the anatomical similarities and differences)
How is the sequence of evolution is proposed
the fossil evidence of various of humans ancestors (the anatomical similarities and differences)
How are hominids classified
bipedal animals in the fossil record that show a mixture of apelike and human like features ape=man
Anatomical similarities of humans and African Apes
Brain- large brain compared to body size
Eyes- stereoscopic vision, eyes are protected by bony sockets
Nose- reduced
Teeth- Variety of teeth for omnivorous diet
Shoulders- collar bone allows arms to rotate freely
Hands- fingerprints, fingers have fingernails not claws, opposable thumb allow for precision grip
Anatomical difference between humans and African apes
brain h- large cranium A- small
brow ridge h- not well developed A- well developed
spine H- s shaped A- C shaped
pelvic gridle H- short with wide pelvis A- long and narrow
palate shape H- small and circular A- long rectangular
jaw H- small less protruding A- large more protruding
cranial ridge H- No cranial ridge A- Cranial ridge
foramen magnum H- forward position A- towards the back end of the skull
What is the genetic evidence for evolution
Mitochondrial DNA- all humans are closely related all humans are linked to a common ancestor. A mutation in the mitochondrial DNA of a female hominid that lived 150 000 years ago
Cultural evidence for evolution (Archeologist)
archaeological evidence ✓ oldest evidence of symbolic thought
found in Africa✓/ e.g. Art (Blombos Cave); ✓
• burial of dead✓ (Klasies Cave, Border Cave); ✓
• tools/artefacts✓ (Pinnacle Cave, Blombos) ✓
(line of evidence ✓ explained ✓) × 2
Which is the oldest Extant people and what is the scientific claim to this
The San People of Southern Africa- lived as hunter gathers
DNAs analysis show they have the most diverse genetic variation this shows that they are oldest population humans on earth
Direct descendants of early Humans and gave rise to all other groups of Africans and all other people who left the continent
Explain How bipedalism, fire making, tool making, Language and culture can be seen as interdependent
Bipedalism frees hands to use tools- free hands allow more development of more complex tools which enabled hominids to hunt larger prey which would increase protein and fate intake which improves brain development an increased brain development improved hunting techniques involving co- operative hunting and gathering around fire which would encourage communication and language development- language and social interaction would encourage culture
What is the multiregional model
Homo erectus migrated from Africa and arrived at various destinations in various places, various populations of homo erectus evolved into homo sapiens
Out of Africa hypothesis
1- humans originated in Africa (all australopithecine and homo habilis/ bipedal organisms fossils have been found only in Africa , oldest h. erectus fossil found in Africa and mtDNA shows oldest female ancestor of humans are from Africa) Homo erectus moved out of Africa Climate change was the driving force
3- Homo erectus spread into the rest of the world and each species of homo adapted to different environment they inhabited
4- In Africa some Homo erectus evolved further into homo sapiens in Eastern Africa and SA a second migration out of Africa occurred by homo sapiens and they dominated all homo species that were in europe
how is bipedalism an advantage
free hands, carry tools whilst walking
see further distances
larger surface area for air current which causes body to cool down, leaving body less dependent of water
How do you measure cranial capacity
measure volume of the brain cast
use cranium to determine the volume
