Mass Extinction Timeline: History of Life on Earth

Mass Extinction Timeline: History of Life on Earth

What marked the start of the mass extinction timeline? How many mass extinction events were there and how did they affect our planet? The mass extinction timeline dates back to the end of the Ordovician period-beginning of the Silurian period. After the Ordovician extinction, there were four more extinction events, the most recent one being the dinosaur extinction 65 million years ago. Here is a brief overview of the mass extinction timeline and the planetary effects of each extinction event.

The Bayou Corne Sinkhole Disaster: Who’s to Blame?

The Bayou Corne Sinkhole Disaster: Who’s to Blame?

What was the Bayou Corne sinkhole disaster? What happened and what did it mean for the people who lived in Bayou Corne? In Bayou Corne, an environmental disaster lead to a sinkhole. Louisiana is staunchly pro-business and pro-energy, and residents of Bayou Corne blamed the government instead of the company at fault, Texas Brine. Read more about the Bayou Corne sinkhole disaster and what happened.

Amphibian Extinction: The Culprit Discovered

Amphibian Extinction: The Culprit Discovered

What are the causes of amphibian extinction? Which amphibian species have and are becoming extinct? Amphibian extinction has come to the attention of scientists in the late 1980s. According to experts, however, we are not only witnessing the amphibian extinction event, we are also causing it. Keep reading to learn about amphibian extinction, which species are affected, and what is causing it.

Megafauna Extinction: Big Animals in Trouble

Megafauna Extinction: Big Animals in Trouble

What is the cause of megafauna extinction? What role did we—humans—play in the decline of biodiversity in the supersized animal kingdom? The causes of megafauna extinction have puzzled scientists dating back to Cuvier’s day, when the fossils of huge unknown creatures began turning up. Researchers have debated whether megafauna disappeared due to climate change or was killed by humans. But most scientists today lean toward blaming humans. Keep reading to learn about megafauna extinction: which species have gone extinct, and what were the causes.

Walter Alvarez and the Asteroid Strike Theory

Walter Alvarez and the Asteroid Strike Theory

Who is Walter Alvarez? How did he come to the conclusion that it was an asteroid strike that wiped out the dinosaurs 65 million years ago? Walter Alvarez was an American geologist who is best known for his asteroid strike theory. In the late 1970s, Alvarez discovered a large amount of iridium in the rock layers in the Gola Del Bottaccione gorge and theorized that there was an asteroid strike 65 million years ago. Keep reading to learn about Walter Alvarez’ asteroid strike theory.

Racial Caste System: It’s More Than Skin Color

Racial Caste System: It’s More Than Skin Color

What is a racial caste system? How did an arbitrary trait such as the color of skin come to shape the destinies of millions? Racial caste system is a hierarchical social order where skin color is used as a tool to designate people’s rank in society. However, race is an arbitrary characteristic because it was invented as a means to stratify society and justify different standards of living. Keep reading to learn about how the racial caste system was created.