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Evolution

Final Exam

Final Exam

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John Tokhi
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John Tokhi
This flashcard set delves into university-level biology, focusing on the intricate processes of evolution, plate tectonics, and the origins of life. It covers key topics such as species extinction, molecular evolution, and the role of environmental factors like water and atmosphere in shaping life. The flashcards explore the impact of geological events, the evolution of metabolism, and the formation of complex molecules. Ideal for students and researchers, this set provides a comprehensive understanding of the mechanisms driving life's diversity and the Earth's dynamic history.
Flashcards
107
Students
1
Language
English
Category
Biology
Level
University
Created / Updated
08.12.2012 / 09.12.2012
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Flashcards

Plate boundaries

Continental drift

Paleozoic Era

Laurasia

North America and Eurasia

Gondwana

India and South America, Africa, Antarctica, Australia (375 mya)

Mesozoic era

Pangaea gradually broke up now.

Cenozoic era

The plates further separated and continents moved into present-day positions

Dispersal

New contacts between continents

Vicariance

Splits species, resulting in separate evolutionary histories.

How are patterns of endemism altered?

Dispersals and Vicariances

Five extinction episodes in the fossil record

Species that died in Late Ordovician

85 species

Species that died in Late Devonian

82 species

Species that died in Late Permian

96 species

Species that died in Late Triassic

76 species

Species that died in Late Cretaceous

76 species

Most severe of all five mass extinctions

Permian-Triassic

Why the most severe extinction?

Asteroid impact or massive volcanism or both

Environmental events at Permian-Triassic boundary

Most likely cause of Permian-Triassic extinction

The Cretaceous-Tertiary extinction event

Asteroid impact hypothesis

First proposed by Luis and Walter Alvarez, 1980. Found world wide geological layer of meteorite dust in sediment cores. Other evidence is microspherules, soot, shocked quartz.

Possible "nuclear winter" scenario from asteroid impact

Dust blocked the sun and everything cooled. A collapse in food chains due to stopping of photosynthesis, but on land burrowing animals survive and plants recover from seed banks.

Volcanism Hypothesis

Suggests that iridium, microspherules, soot, shocked quartz may be volcanic in origin. And massive eruptions from Deccan Traps and that is what created the dust and the cooling and everything

The "Smoking Gun" hypothesis

Massive impact crater dated to the K-T was found off the coast of Yucatan Peninsula, the Chicxulub crater. 1992.

The role of chance in the evolution of life

The direction of evolution was altered by each mass extinction event. Loss of dinosaurs paved the way for the rise of mammals.

Questions that evolution brings up.

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