Transcript Bauman_Were Humans responsible for the Glacial Extinctionsx

Did Humans Cause the
Glacial Extinctions?
By: Alex Bauman
Do you think that humans are the
sole reason for the extinctions?
Scientists Continue to Disagree
Changes in habitat
Hunting by humans
Combination of both reasons
Woolly Mammoths
 The fossil record puts the mammoth at 300 kyr - 3.7 kyr
on Wangle Island in the Atlantic Ocean.
 The change in climate from between 126 kyr - 21 kyr 6 kyr led to a change in the vegetation and reduced the
mammoth’s steppe-tundra habitat.
 Like during the last interglacial period, mammoths
would have gone into small pockets of populations
making them easier targets for humans hunting.
Giant Deer

Thrived from 400, 000 years
-male skeleton with antlers from Kamyshlov (6.9 kyr)
-male skull with cervical vertebrae from Redut river
(7.0kyr)
 Living in what is now Russia these two giant deer could
have survived in the Urals or Western Siberia.

For a explanation of their extinction : the population
could have been forced onto the plains from the Ural
foothills due to the vegetation changes where they would
have been gullible to hunting pressure.
Saber Tooth Cat
 Two of the largest terrestrial carnivores that lived during
the Pleistocene were the saber toothed cat, Smilodon
fatalis, and the American Lion, Panthera atrox.
 1993 – a study was made that looked at the broken teeth
of fossils and considered that evidence that they were
chewing bones from kills
 2012 – a study covered same things but came to the
conclusion that there was no difference in the use of
carcasses compared to different times
My Opinion
 For many mammals of the Last Glacial Period,
they would have shrunk in population size during
the Last Interglacial Period (126 kyr) just like they
are doing now.
 The only thing different now compared to then was
that humans were present.
 Without climate change changing the location of
their food and habitat I find it hard to believe that
we would have caused any great difference in
population sizes of the large mammals.
Questions?
References
Ananthaswamy, A. (2010). Bye-bye mammoth, hello hotter
world. New Scientist, 207(2768).
DeSantis, L.R.G., Schubert, B.W., Scott, J.R., & Ungar, P.S.
(2012). Implications of diet for the extinction of saber-toothed
cats and American lions. PLoS ONE, 7(12), 1-9.
Haynes, G. (2002). The catastrophic extinction of North
American mammoths and mastodonts. World Archaeology,
33(3), 391-416.
Nogues-Bravo, D., Rodriguez, J., Hortal, J., Batra, P., & Araujo,
M.B. (2008). Climate change, humans, and the extinction of
the woolly mammoth. PLoS Biology, 6(4), 685-692.
Stuart, A.J., Kosintsev, P.A., Higham, T.F.G., & Lister, A.M.
(2004). Pleistocene to Holocene extinction dynamics in giant
deer and woolly mammoth. Nature, 431, 684-689.