Macroevolutio1 - mya). A second extinction occurred in the...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Macroevolution A Brief History of Life Geological and paleontological evidence has allowed us to piece together a picture of how life on earth evolved from the earliest single-celled organisms to the diversity of single- and multi-celled organisms that have lived through history. Figure%: History of Life on Earth Mass Extinctions The history of life on earth is punctuated by a series of mass extinctions, during which the number of species on earth plummeted. Each of these extinctions changed the landscape of global diversity and allowed new types of organisms to thrive in the aftermath.
Background image of page 1

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

View Full DocumentRight Arrow Icon
The first mass extinction occurred in the Ordovician period, about 500 million years ago (500
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: mya). A second extinction occurred in the late Devonian period, about 360 mya. This extinction paved the way for a diversification of land plants, insects, and amphibians in the Carboniferous period. The next mass extinction took place at the end of the Paleozoic era in the Permian period, about 250 mya. After this extinction, marine and reptile diversity increased greatly, eventually leading to the "Age of the Dinosaurs." The dinosaur age crashed to a halt in the late Cretaceous period (70 mya), when the most recent mass extinction eliminated the last dinosaurs and allowed mammals to become a dominant form of life....
View Full Document

Page1 / 2

Macroevolutio1 - mya). A second extinction occurred in the...

This preview shows document pages 1 - 2. Sign up to view the full document.

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