Sixth Extinction Flashcards
Rhetorical Purpose
In the pages that follow, I try to convey both sides: the excitement of what is being learned as well as the horror of it. My hope is that readers of this book will come away with an appreciation of the truly extraordinary moment in which we live.
Big Five
Five Major extinctions in the past where the planet has undergone changes so violent and sudden that the diversity of life has plummeted
Wake and Vredenburg
discovered that sixth extinction is underway
The Sixth extinction
A mass extinction that is occurring in the present, caused solely by by humanity’s transformation of the ecological landscape.
chytrids fungus
fungus discovered on the skin of dead frogs. causing the disappearance and deaths of mont frogs all over the world
Mass extinctions
defined as events that eliminate a significant proportion of the worlds biota in a geologically insignificant amount of time
“Out of Africa” theory of the Chytrid fungus
theorizes that the fungus moved around the world with shipments of african clawed frogs
“Frog leg soup” theory of the chytrid fungus
theorizes that it was spread by american bullfrogs shipped to other countries for human consumption
American Mastodon
Its remains brought up the question and idea of animals that no longer existed
Cuvier
French scientist. Looked at elephants from Asia and Africa and saw they were different species. Also discovered existence of lost species. established extinction as a fact. Brought up ideas of a globe wracked periodically by cataclysm.
Lamarck
Thought that animals could alter their physical traits wile they were still alive by changing their habits. He was wrong
Lyell
Uniformitarian. Thought that every feature of the landscape was the result of very gradual processes operating over countless millennia.
Darwin
Came up with the idea of evolution, that organisms had come into being through a process of transformation that took place over countless generations. This theory of the appearance of species doubled as one for how they disappeared. Driving both was the struggle for existence.
Auks
killed off by Europeans for food and feathers. Eventually extinct
Walter Alvarez
Discovered first traces of the asteroid that ended the Cretaceous period
Luis Alvarez
Father of Walter. He used iridium on the clay found at the impact site of the asteroid
iridium
used on clay found in Gubbio to determine that there was a spike in iridium at the very end of the Cretaceous period. Since iridium is found in asteroids, the theory arose that an asteroid ended this period.
The impact hypothesis
attributed to the Alvarez’s says that sixty-five million years ago, an asteroid six miles wide collided with the earth. Exploding on contact, it released energy on the order of a hundred million megatons of TNT, or more than a million of the most powerful H-bombs ever tested. Debris, including iridium from the pulverized asteroid, spread around the globe. Day turned to night, and temperatures plunged. A mass extinction ensued.
Ordovician Extinction
First of the Big Five extinctions. At the end of the Ordovician, some 444 million years ago, the oceans emptied out. Something like eighty-five percent of marine species died off. CO2 levels and temperatures dropped and glaciation occurred.
End-Permian / Permo-Triassic extinction
Biggest of the Big Five extinctions. Almost eliminated all multicellular life. Seems to have been triggered by a change in climate. Massive release of carbon in the air, temperatures rose tremendously. Water became acidified and oxygen levels in oceans became so low that organisms probably suffocated.
Anthropocene
Term invented by Paul Crutzen to describe the epoch in which we live. Period where human activity has been the dominant influence on the climate and enviroment
Chapter 13
I’ll Get to that later…
Frozen Zoo
Center in San Diego where cultures of animal cells are kept. Some alive, some extinct.
Kinohi
One of the last alala birds (Hawaiian crows). He is kept in a facility in San Diego. Barbara Durrant is trying to save his species.
