Lecture 23: Human Evolution Flashcards
When was the first published evolutionary theory and who produced it?
1859 by Charles Darwin
What was the name of Charles Darwin’s first evolutionary theory?
On the origin of species by means of Natural Selection
Why was Darwin’s first evolutionary theory rejected?
Because of strong religious beliefs
What did Darwin add to his evolutionary theory in 1871?
The process that made the link between the evolutionary process and humans
Why was Darwin’s theory still rejected after 1871?
Because of continued religious beliefs and he did not have any intermediary species between apes and humans
When did evidence of intermediary species emerge and who produced it?
Towards the end of the 19th century due to Eugene Dubois
How did Dubois provide evidence of intermediate species?
He conducted investigations in Java where he discovered the remains of Homo Erectus.
How did Dubois’ evidence develop in the 1920s?
He found further remains of hominin in Africa
What evidence was there for evolutionary species in Germany but what was it discarded as at the time?
Hominin bones that were thought at the time to come from a diseased human
What is the biggest biological taxonomy ranking
Kingdom (Animalia) Phylum (Chordata) Class (Mammalia) Order (Primate) Family (Hominidae) Genus (Homo) Species of the Homo (Sapiens)
What are Kingdom (Animalia) taxa? What taxonomy is before and after this taxa?
Organisms that can move on their own. None before, Phylum (Chordata) after
What are Phylum (Chordata) taxa? What taxonomy is before and after this taxa?
Animalia with a back bone.
Kingdom (Animalia) is before and Class (Mammalia) are after
What are Class (Mammalia) taxa? What taxonomy is before and after this taxa?
Chordates with fur/hair and milk glands. Phylum (Chordates) are before and Order (Primate) are after
What are Order (Primate) taxa? What taxonomy is before and after this taxa?
Mammals with collar bones and grasping fingers. Class (Mammalia) are before and Family (Hominidae) are after
What are Family (Hominidae) taxa? What taxonomy is before and after this taxa?
Primates with relatively flat faces and 3d vision. Order (Primates) are before and Genus (Homo) are after
What are Genus (Homo) taxa? What taxonomy is before and after this taxa? (biggest taxa order)
Hominids with upright posture and large brains. Family (Hominidae) are before and Species (Sapien) are after
What are Species (Sapien) taxa? What taxonomy is before and after this taxa?
Homo with high forehead and thin skull bones. Genus (Homo) are before and none are after other than the in-depth modern human taxa
What is the ranking of taxa that most closely resemble the modern humans?
Family (Hominidae) Subfamily (Homininae) Tribe (Hominini) Subtribe (Hominina) Genus (Homo) Species (Sapiens)
What are family (hominidae)? What taxonomy is before and after this taxa? (modern human taxa order)
Orangutans, gorillas, chimpanzees and humans. None before and Subfamily (homininae) after
What are subfamily (homininae) taxa? What taxonomy is before and after this taxa?
Gorillas, Chimps and Humans. Family (Hominidae) are before and Tribe (Hominini) are after
What are tribe (hominini)? What taxonomy is before and after this taxa?
Panina (chimps), Hominina (Humans) and Australopithecina. Subfamily (homininae) are before and subtribe (Hominina) are after
What are subtribe (hominina)? What taxonomy is before and after this taxa?
Homo Genus. Subtribe (Hominina) are before and Genus (Homo) are after
What are Genus (Homo)? What taxonomy is before and after this taxa?
Homo Sapiens + around 15 other Genus. Subtribe (Hominina) are before and Species (sapiens) are after
What are species (sapiens)? What taxonomy is before and after this taxa?
Anatomically modern humans. Genus (homo) are before none are after
What are the two key terms for human taxonomy?
1) Hominid (Family: Hominidae): these are the Great Apes of which there are 8 types today
2) Hominin (Tribe: Hominini): these are the members of Homo Genus i.e. they are humans and their closest ancestors
What is important to know about the most recent chapters of human taxonomy?
There is a lot of uncertainty
What are sahelanthorpus tchadensis? when were they dated back to?
the first divergence of us form chimps i.e. the first hominins. dated back to ~7-4mya
Describe the sahelanthorpus tchadensis? (brain size, features, walked upright)
chimp and human features
brain size comparable to modern chimp
may have walked upright
What are Australopithecus anamensis? when are they dated back to?
next step after sahelanthorpus tchadensis. ~4mya
Describe the Australopithecus anamensis (dentistry, walked upright)
probably walked upright and teeth adapted to eating tough food
When are Australopithecus afarensis dated to?
~4.5mya
Describe Australopithecus afarensis? (height, brain size, stone tools, upright walking)
walked upright
1.2-1.4m tall
brain size 35% of homo sapien
no stone tools
What is the human taxa significance of homo habilis? When were they dated to?
first taxa in the homo genus stages. ~1.8mya
Describe homo habilis (first taxa, brain size, stone tools)
First in the homo genus stages
Brain size 50% of homo sapiens
Primitive stone tools used
What is the taxa significance of homo ergaster and when were they dated to?
Transition homo genus taxa after homo, the first homo habilis. ~1.8-1.7mya
Describe homo ergaster? (brain size, tools, features, first to discover)
small face and teeth
brain size 60% of homo sapien
advanced stone tools developed
Possible first use of fire
What period were homo erectus remains first dated to?
~1mya
Describe the homo erectus (brain size, spatial significance, relevance to homo sapiens (2), survival)
similar anatomy to homo sapiens brain 60-70% of homo sapiens Successful survival species as they lasted around 2 million years (from ~2mya, they existed before the evidence was dated) First species discovered out of Africa Coexisted with homo sapiens
Where was most of the evidence for previous taxa found?
Africa
Where in Africa were Sahelanthorpus tchadensis first found?
Middle - isolated from other species remains
What taxa were found in a very similar spot to Sahelanthorpus tchadensis many years later? when?
Australopithecus Bahrelghazali (2.8mya)
When and where was the first homo found, what taxa was it?
1.8mya - homo habilis - Eastern Coast of Southern Africa
When was the first homo erectus evidence dated to and what was it the first homo to do? which places did they go to after this period?
1.7mya - it was the first to leave Africa where it emigrated to places in middle East and then Turkey and Georgia
Where did homo erectus reach by 1.4maya and how?
Indonesia through India
Where had the homo erectus reached by 800kya?
North Africa, China and Central and Eastern Europe
When did the homo heidelbergensis find their way out of Africa and where did they go?
500kya - similar places to homo erectus (China, North Africa and maybe even Europe)
What was the significance of the homo heidelbergensis in the human evolution taxa?
Watershed species just before the divergence in to homo neanderthalensis and homo sapiens
Describe homo heidelbergensis characteristics in terms of the modern human taxonomy order?
88% brains of homo sapiens
Used tools like homo erectus
What happened to the homo heidelbergensis that emigrated to Europe?
Developed Neanderthal-like features
What happened to the homo heidelbergensis that remained and occupied Africa?
Developed in to Homo Sapiens possibly
What period is identified for the transition phase in to homo neanderthalensis and homo sapiens from homo heidelbergensis?
250kya
What are the three distinct species on the earth that have been identified after the 250kya transition phase? And what are the three aras that they predominantly occupied?
Homo Neanderthalensis - Europe
Homo Sapiens - Africa (North and West)
Homo Erectus - India to Indonesia to China
Describe how homo neanderthalensis had evolved by the 130/125kya checkpoint phase
stocky and adapted to cold climate, used advanced tools, had a social structure and rudimentary landguage
Describe how homo sapiens had evolved by 130/125kya checkpoint phase
Cultural ability, complex tools practical and social innovation
When did Homo Sapiens find their way out of Africa?
125kya
What are the two theorised phases of homo sapien dispersal and the places they migrated to?
1) Early (120kya) - middle East, Southern Asia and Australia
2) Late (60kya) - Europe, Northern Asia and Indonesia
What is thought could have happened as homo sapiens found their way in to Europe?
competition, conflict and copulation with homo neanderthalensis
What strong evidence is there for the coexistence of neanderthalensis and sapiens?
Tools and technology that each used were dated and found to overlap with each other for a period of 2,600 to 5,400 years
What was the name given to the neanderthas and modern human tools?
Neanderthals: Mousterian
Modern Humans: Uluzzian
What is thought that Neanderthals could have done with tools used by modern humans?
Copied the tools of modern humans or used them for inspiration
When does evidence for Neanderthals disappear?
40kya
What are the possible reasons for the disappearance of Neanderthals from the record?
Conflict: there is evidence for injuries from weapons on late Neanderthal fossils
Competition: Neanderthals were socially isolated and less likely to be able to avoid predators and keep warm compared to modern humans that were better equipped
Copulation: inter-breeding between species meant that that faded out of record
What tectonic activity took place in East Africa and what impact did this have on the landscape/environment?
Tectonic activity transformed the region from homogenous desert landscape to heterogeneous cloud forests. It also lead to the Rift Valley which lead to lake formation
What biological evolutionary processes happened to humans that took place at the same time as the African landscape changes?
speciation, encephalisation, hominin dispersal
What is encephalisation?
An evolution in complexity and size of the brain
What time is the overlap between African landscape change and human evolution most evident?
1.8mya
What is the cause for the overlap between African landscape change and human evolution?
unknown
What happened to the ITCZ over Africa and why?
Southerly migration of ITCZ caused by Heinrich events
What impact did the Southerly migration of the ITCZ have on the environment and consequently human migration?
Cooler and drier climate meant vegetation changes which produced uninhabitable areas promoting homo sapiens to move out of Africa which led to their global dispersal
What impact did the last glacial event have on human evolution and dispersal?
Neanderthals and sapiens forced out of Europe toward South where it was warmer. Neanderthals were poorly adapted to this warmer climate and fauna so were outcompeted by the sapiens
