LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf ·...
Transcript of LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf ·...
![Page 1: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/1.jpg)
LLL Innis 2018
TERTIARY AND QUATERNARY CLIMATE CHANGE AND THE
EVOLUTION AND SPREAD OF HUMANS.
![Page 2: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/2.jpg)
Today’s uplifting message!
![Page 3: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/3.jpg)
![Page 4: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/4.jpg)
Last week we saw that a record of
climate change extends back about 4
billion years. It’s a record of
changing sedimentary
environments and the emergence
and evolution of life. The record is
limited until the last 600 million
years; since the Cambrian and the
apparently rapid diversification of life
known as the Cambrian Explosion.
![Page 5: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/5.jpg)
The record of biodiversity through the last 600 million years indicates a logarithmic increase in species through time. However, the increase is not a smooth one. It is interrupted by several mass extinction events at which biodiversity is drastically reduced – the Big Five mass extinctions. The largest occurred at the end of the Permian when perhaps 90% of species went extinction. The latest one, at the Cretaceous-Tertiary (K-T) boundary, had about a 70% loss.
![Page 6: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/6.jpg)
![Page 7: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/7.jpg)
All except the K-T extinction appear to
have been caused by a complicated set of
mechanisms determined by plate
tectonics. At the K-T boundary we can
make a good case for asteroid impact as
the cause.
That boundary is very significant for us.
From that time we see modernization of
the biosphere – the rise of mammals,
insects, birds, flowering plants, etc.
![Page 8: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/8.jpg)
Evolution of animals V= birds, BB= placental
mammals
![Page 9: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/9.jpg)
Evolution of plants and animals after the K-T event .
angiosperms=flowering plants, ungulates=hoofed
animals, macropods= marsupials.
![Page 10: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/10.jpg)
The early Tertiary was warm, but cooled through
the Eocene. By the Pliocene, the world had
significant ice. By the Pleistocene, there were
frequent advances and retreats of ice across
Europe and North America.
![Page 11: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/11.jpg)
The pulse-like ice expansions (glacials)
and contractions (interglacials) seem to
have been driven by Milankovitch
Effects.
![Page 12: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/12.jpg)
As climate cooled, tropical rainforests
contracted and were replaced by
grasslands and deserts in the tropical
zone, and the biomes familiar to us –
prairies, boreal forest, temperate
broadleaved forests - formed. Until then,
much of North America would have been
forested. Until the mid-Tertiary, these
forests extended across the Arctic
archipelago!
![Page 13: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/13.jpg)
Present global
biomes(left) and in
the Eocene
(below)
![Page 14: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/14.jpg)
Tertiary fossil forests
in the Canadian
Arctic.
![Page 15: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/15.jpg)
One order that evolved was the Primate Order. We evolved from these as the family Hominideae, in the genus Homo. Our species? Homo sapiens.
This evolutionary process appears to have been largely driven by the global climatic changes from the mid-Tertiary.
As climate cooled, tropical rainforests contracted and were replaced by grasslands and deserts in the tropical zone. Until the mid-Tertiary, much of the Arctic archipelago had forest cover.
![Page 16: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/16.jpg)
Currently there
are 16 families,
72 genera and
about 350
species of
primate.
![Page 17: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/17.jpg)
Evolution of primates.
Our ancestors, the primates, were once widely
distributed, but they have always been largely
tropical fauna and largely arboreal.
Thus, climatic cooling caused their contraction
into the current tropical zone and the loss of
forest cover stimulated some to become ground
dwellers. This required the exploitation of
different resources so there were morphological
and behavioural changes. The most obvious of
the latter was the development of bipedalism.
![Page 18: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/18.jpg)
Current distribution of primates
![Page 19: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/19.jpg)
Our lineage
![Page 20: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/20.jpg)
Early primate
![Page 21: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/21.jpg)
Ring-tailed lemurs. Lemurs are
confined to Madagascar. Why?
![Page 22: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/22.jpg)
Old and New
World
monkeys.
![Page 23: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/23.jpg)
We share about 96% of our genes
with gorillas
![Page 24: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/24.jpg)
And 98% with chimpanzees
![Page 25: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/25.jpg)
Our African Origins;
Although climatic changes through
the Tertiary were global, the evolution
of hominids/hominins was not . It was
confined to Africa. Was this because
Africa had a suite of environmental
conditions that only allowed our
evolution to occur there or was it
fortuitous?
![Page 26: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/26.jpg)
Why Africa?
(a) increasing aridity and seasonality
leads to major contraction of once
extensive rainforest
(b) expansion of tropical savanna
(c) creation of isolated forest fragments
in a ‘sea’ of savanna
(d) isolation facilitated by uplift and
volcanism in the Rift Valley system
![Page 27: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/27.jpg)
(e) strong seasonality with fire a natural
part of the cycle, and long animal
migrations.
(f) strong coevolutionary associations
between herbivores, carnivores and
scavengers.
![Page 28: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/28.jpg)
![Page 29: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/29.jpg)
![Page 30: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/30.jpg)
Massive environmental changes then triggered life-style and dietary changes in hominids. Obvious consequences included bipedalism and an increase in body (and brain) size.
![Page 31: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/31.jpg)
These responses are evident with both
proto humans and all species of Homo.
The proto humans are usually considered
to be the Australopithecenes. A.
afarensis , Lucy, is the best known of
these. A new genus, Ardipithecus, was
recently recognized. It predates the
Australopithecines.
About 2.6 MYBP the first species of Homo
(H. habilis) appeared, then H. erectus.
![Page 32: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/32.jpg)
![Page 33: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/33.jpg)
Bipedalism; Bipedalism may be seen as a
response to changing lifestyle; from
being arboreal to a life on the ground.
Benefits – increasing mobility,
increasing travel range, arms no
longer required for locomotion,
height gain, tool preparation,
thermoregulation, etc.
![Page 34: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/34.jpg)
Changes from knuckle-walking to
full bipedalism
![Page 35: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/35.jpg)
Increasing Size;
Increasing size was associated with broadened dietary niche, increased home range, increased mobility, change in scavenging activities, increase in thermoregulatory efficiency, increased longevity, slower reproductive rates, increasing brain size and complexity, increasing sociality.
![Page 36: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/36.jpg)
Increasing
brain size and
complexity
![Page 37: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/37.jpg)
Is there a correlation between
brain size and environmental
stress?
![Page 38: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/38.jpg)
Humans appear to be confined
to Africa until the exodus of
Homo erectus about 1.7
million years ago.
In the light of recent
discoveries, what happened
after that is becoming more
murky than it was.
![Page 39: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/39.jpg)
Some wrenches in the works;
The Jebel Irhoud site in Morocco –H.
sapiens here at 300,000 YBP ?
The Misliya site in Israel – 200,000
YBP ?
H. erectus sites in Britain – 1 MYBP?
![Page 40: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/40.jpg)
Happisburgh site, Norfolk, UK
![Page 41: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/41.jpg)
Our global diaspora.
Two main models have been proposed to explain the spread of humans around the globe;
1. The Out of Africa Model – by which human evolved in Africa then spread to other parts of the world (twice!).
2. The Multiregional Model – initial spread by H. erectus, then regional evolution of various strains of H. sapiens.
![Page 42: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/42.jpg)
Both models propose an initial migration by Homo erectus around 1.7 million years ago, but they differ with what ensues.
The Out of Africa model is the most popular, but on the basis of recent discoveries, it appears to be far too simple and may also require rethinking of H. sapiens’ origins.
![Page 43: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/43.jpg)
![Page 44: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/44.jpg)
Homo erectus and the first
Out of Africa exodus.
![Page 45: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/45.jpg)
H. sapiens already Out of Africa?
![Page 46: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/46.jpg)
A second exodus and
interbreeding with H. erectus?
![Page 47: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/47.jpg)
Consolidation and further
expansion?
![Page 48: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/48.jpg)
The later migrations
![Page 49: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/49.jpg)
So modern humans evolved earlier than
previously thought.
‘Where’ is now not obvious.
They spread probably at least 100,000
years earlier than previous estimates.
There were probably several exoduses.
They interbred with species evolved from
the much earlier Homo erectus
movement out of Africa.
![Page 50: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/50.jpg)
The role of climate?
Climate provides an envelope in which
biota evolve, exist and expire.
Changing climate undoubtedly
constrained the evolution of hominins,
their geography and their global
expansion.
Much of that evolution took place during
the ice advances and retreats of the
Quaternary.
![Page 51: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/51.jpg)
Glacial advances shaped their movements.
Ice impeded movement in Europe and determined dispersal routes in North America.
At full glacials, sea level was 120 m below current levels. The resulting land connections facilitated dispersal from Africa, across the Near East ,through southeast Asia to Australia and from Siberia into Alaska (Beringia).
![Page 52: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/52.jpg)
Sea level at maximum glaciation –
120 m below current sea level.
![Page 53: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/53.jpg)
![Page 54: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/54.jpg)
Beringia and
human entry to
the Americas.
![Page 55: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/55.jpg)
Late Pleistocene megafaunal
extinctions
The early migrations did not seem to cause any obvious environmental impacts, but the later ones (to Australia and the Americas ) are marked by a massive die off of large animals (megafauna). In North and South America, 75-80% of big animals became extinct. In Australia, over 80%.
![Page 56: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/56.jpg)
North American Megafauna
![Page 57: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/57.jpg)
Australian Megafauna
![Page 58: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/58.jpg)
The coincidence of these extinctions with the arrival of humans on those continents suggests an anthropogenic cause, but the events occurred in times of rapid and large climatic shift. Climatic change is likely to have been at least a contributing factor.
![Page 59: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/59.jpg)
Extinction of Irish Elk and Mammoth
in Eurasia
![Page 60: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/60.jpg)
Pattern of Extinction in North
America
![Page 61: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/61.jpg)
Cave Art – Lascaux, France.
![Page 62: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/62.jpg)
Australian
aboriginal rock art.
![Page 63: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/63.jpg)
How could small populations
with limited technology
eliminate large numbers of big
animals?
Why didn’t the extinction of
large animals happen in Africa
and Eurasia?
![Page 64: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/64.jpg)
So, the first major environmental impact
of humans may have been the mass
extinction event in the Late
Pleistocene/Early Holocene.
It’s also from this time that we have the
first evidence of plant and animal
domestication.
Domestication brought food surpluses,
allowed population increase,
urbanization, stratification of society –
the emergence of civilization.
![Page 65: LLL Innis 2018 - University of Torontosites.utoronto.ca/innis/lll/includes/pdf/2018-LLL-B-4.pdf · 2018-02-02 · Last week we saw that a record of climate change extends back about](https://reader036.fdocuments.net/reader036/viewer/2022070816/5f0fbd607e708231d445a5f7/html5/thumbnails/65.jpg)
We were going to look at plant
and animal domestication and
its consequences next week,
but because of scheduling
issues it will wait until Feb. 16.
Instead, we’ll talk about El Nino
(ENSO) and its impacts on past
and present societies.