A Brief History of Life on Earth

These flashcards cover key concepts related to the history of life on Earth, including methods for dating fossils, the significance of extinction events, and the geological time scale.

Fossil Record Bias

The fossil record is biased due to various factors, including the selective preservation of certain species and environmental conditions.

Relative Dating

A method of determining the age of fossils by comparing them to other fossils or geological layers.

Absolute Dating

A method of determining the actual age of a fossil using techniques like radiometric dating.

Mass Extinction Events

Significant events in Earth's history where a large number of species became extinct in a relatively short period of time.

Radioactive Isotopes

Atoms of elements that decay at a constant rate over time, used in radiometric dating to determine the age of fossils.

Cambrian Explosion

A period approximately 542 million years ago marked by a rapid diversification of life on Earth.

Hadean Eon

The earliest period in Earth's history, from the formation of the planet about 4.6 billion years ago to about 4 billion years ago.

Proterozoic Eon

The geological eon that extends from 2.5 billion to 541 million years ago, during which the first multicellular life forms appeared.

Phanerozoic Eon

The eon that began about 541 million years ago and is characterized by the presence of abundant fossil evidence.

Extinction Importance

Extinction plays a critical role in evolution by allowing for the diversification of surviving organisms and the emergence of new species.