BISC208 Lecture Notes - Lecture 4: Geologic Time Scale, Lamarckism, Natural Selection

• School: University of Delaware
• Department: Biological Sciences
• Course: BISC208
• Professor: Safran Catherine

Document Summary

Evolution- species are not static, change throughout time. Lamarckian evolution is progressive- always producing a larger and more complex species. Giraffes develop long necks as they stretch to reach leaves, pass that trait to offspring. Darwin used population thinking- variation among populations is the most important in evolution. His theory was revolutionary because it overturned the idea that species were static and unchanging. Descent with modification- species that lived in the past are ancestors of living species today, species change throughout time. Fossil- any trace of an organism that has lived in the past. Fossil record- consists of all the fossils found on earth. Darwin interpreted extinct species as evidence that species change. Geologic time scale- sequence of named intervals called eons, eras, and periods that represented the major events in earth"s history. Transitional feature- trait in a fossil species that is intermediate between those of ancestral and derived species.