1 / 10

Evolution

Evolution. The Fossil Record. The Fossil Record. A fossil is a trace of a long-dead organism. Many different kinds of fossils have been found. Molds - imprints Casts – rocklike models Amber Tracks of animals. Types of Fossils. The Fossil Record (cont’d).

Ava
Download Presentation

Evolution

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Evolution The Fossil Record

  2. The Fossil Record • A fossil is a trace of a long-dead organism. • Many different kinds of fossils have been found. • Molds - imprints • Casts – rocklike models • Amber • Tracks of animals

  3. Types of Fossils

  4. The Fossil Record (cont’d) • The history of the Earth and its life-forms can be inferred by examining the fossil record.

  5. The Fossil Record (cont’d) • The fossil record shows • Forms of organisms appeared, lasted for long periods of time and then disappeared (became extinct). • Followed by newer forms of life that also eventually disappeared.

  6. The Fossil Record (cont’d) • There were several mass extinctions. • Probably resulted from drastic changes in the environment.

  7. Law of superposition New geologic strata (layers of rock) are deposited on top of older strata. Relative age: one fossil or rock is older than another. Distribution of fossils

  8. Absolute age: actual age in years. Can be determined by radiometric means (half-life). Distribution of fossils

  9. Distribution of fossils (cont’d) • Using these data, scientists have determined that the Earth is about 4.5 billion years old.

  10. Biogeography • The study of geographical distribution of fossils and of living things. • Shows that new organisms arise in areas where similar now-extinct forms once lived.

More Related