Key Knowledge 13 Flashcards
mammals
warm-blooded vertebrates belonging to the taxonomic class Mammalia that have mammary glands, hair/fur, three middle ear bones, and one lower jawbone
primates
the highest order of mammals, comprised of about 400 different living species who share a number of features including opposable digits and binocular vision
hominoids
members of the superfamily Hominoidea that includes apes and humans
hominins
members of the taxonomic tribe Hominini that includes modern humans and our upright-walking ancestors
changes in brain size
over time, the hominin braincase has tended to increase in size.
This included a range of other morphological changes, including a flatter face and a more domed skull.
changes in limb structure
modern humans have a smaller arm to leg ratio than our earlier ancestors. This was due to a variety of reasons, including the fact that longer legs were more energy efficient for bipedalism.
Changing pelvis shape
hominins evolved a narrower and more bowl shaped pelvis over time, which developed in relation to our bipedal lifestyle and larger brain cases.
inference
conclusions or assumptions reached by analysing and extrapolating from evidence
Recent evidence supporting Human-Neanderthal interbreeding
Nuclear DNA studies in 2010 show around 1–4% of the human genome is identical to DNA found in Neanderthals. This 1–4% similarity was only found in the genomes of non-African populations and not in sub-Saharan African genomes.
100 000 year old DNA from Neanderthal fossils found in Siberia in 2016 contained a significant amount of ancient human DNA not found in other Neanderthal populations.
Recent evidence supporting Human-Neanderthal interbreeding (interference)
Neanderthals may have interbred with humans as they left Africa somewhere in the Middle East around 65 000 years ago and did not interbreed with African humans.
A population of Neanderthals in Siberia may have interbred with an early form of humans around 100 000 years ago. This suggests a second interbreeding event with humans.
New Hominin species
In 2010, scientists reported the discovery of bone fragments of a new hominin species in Denisova Cave in Siberia. The bones were dated to around 40 000 years ago. Upon analysis, nuclear DNA from the bone was found to be very closely related to Neanderthals, but different enough to be a new distinct species, termed Homo Denisova, or Denisovans.
multiregional hypothesis
a model for the geographical spread of Homo sapiens which suggests that separate human populations evolved independently from earlier hominins that had spread throughout Eurasia and experienced gene flow. Also known as the regional continuity model
Out of Africa hypothesis
a model for the geographical spread of Homo sapiens which suggests that humans first developed and evolved in Africa before migrating outwards and expanding their colonies, replacing the earlier hominins that had spread prior. Also known as the African replacement model
Aboriginal Australians
Modern Aboriginal Australians can trace their lineage back to this first migration out of Africa, where it is believed that around 50 000 to 65 000 years ago the first humans arrived on the land. This makes Aboriginal Australians one of the oldest continuous populations on earth, and has tremendous impacts on Aboriginal peoples Connection to Country
