363 lecture 8-2008 - Current mass extinction

363 lecture 8-2008 - Current mass extinction - Reading...

Info iconThis preview shows pages 1–14. Sign up to view the full content.

View Full Document Right Arrow Icon
Reading assignment For 2/11: Chapter 10: Overexploitation For 2/13: Chapter 8: Vulnerability For 2/15: Chapter 9: Habitat destruction
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Bottke and colleagues 2 propose that the collisional break-up of an asteroid 160 million years ago was the ultimate cause of the mass extinction on Earth at the Cretaceous– Tertiary boundary some 95 million years later. This occurred when one particularly large fragment, the Chicxulub impactor, hit Earth. The inset shows an inferred remnant of this meteorite, retrieved from clays in the northern Pacific dating to the same time as that event 11 . Asteroid belt between Mars and Jupiter; 60 km and 170 km bodies colliding.
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Cosmic rays or bursts of gamma rays as an explanation for dinosaur extinctions Looked for signs of cancer in fossilized bones of 708 dinosaurs, compared with incidence of bone cancer in modern birds and reptiles. No evidence for elevated cancer rates in dinosaurs.
Background image of page 4
Some Neandertals had red hair and pale skin, as seen in this reconstruction of a French fossil.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Giant senai – a Tanzanian elephant shrew
Background image of page 6
What famous scientist was born 199 years ago yesterday? 12 February 1809
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Dispersal of Humans Nature 7 Dec. 2000 p. 653.
Background image of page 8
Climate Change in Pleistocene Humans arrive in Australia Humans arrive in America
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Australia Colonized ~ 50,000 years ago. No global warming at this time. Offers a natural experiment to compare human predation and climate change.
Background image of page 10
Gifford Miller, 1999 Genyornis emu
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Genyornis (1999 research) Miller et al., 1999. Science 283: 205-208 emu
Background image of page 12
More than 85 percent of Australian terrestrial genera with a body mass exceeding 44 kilograms became extinct in the Late Pleistocene. Although most were marsupials, the list includes the large, flightless mihirung Genyornis newtoni . More than 700 dates on Genyornis eggshells from three different climate regions document the continuous presence of Genyornis from more than 100,000 years ago until their sudden disappearance 50,000 years
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 14
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 33

363 lecture 8-2008 - Current mass extinction - Reading...

This preview shows document pages 1 - 14. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online