Evidence of Evolution – notes Name:
Evolution is more than just a “theory” / A theory stating that things ______over time.In Science, evolution refers to the process in which organisms produce offspring which are biologically different than their ancestors, yet are more capable of surviving and producing offspring in the environment.
A theory, in science, is a widely ______set of explanations of observations and phenomena.
1. Are more than an educated ______
2. Can never be ______, only disproved.
3. Have ______that support it.
4. Become more widely accepted with more evidence supporting them.
Charles Darwin – credited with the theory of evolution / In 1859, published: The Origin of Species by Means of Natural Selection.
Major idea of his work: Organisms living today have been produced through a long slow process called______.
Evidence that Darwin used to support his theory
Relative Dating
Homologous Structures
Vestigial Structures
/ 1. ______- study of extinct life
______- most found in sedimentary rock where bone has been replaced by minerals. (Fossils found in tar, amber, or ice may be better preserved)
- Provides ______about the history of life
- Shows how organisms have ______over time
- Fossil record is incomplete because most organisms ______without leaving any trace!
- Shows that there were several mass extinctions (dying off of large numbers of organisms)
______: Some radioactive elements
breakdown over time at a known, steady rate. Each radioactive element has a
different half life.
Ex: U-238 has a half life of 4.5 billion years
C-14 has a half life of 5,770 years
______: Lower layers of rock are usually older than the layers above. Can be less accurate than radioactive methods due to erosion, faulting from earthquakes, etc.
(Using data collected from rock samples from the Earth, moon, and meteorites, most scientists agree that the Earth is about ______years old)
2. ______- unrelated species now living on different continents, under similar ecological conditions evolve certain striking features in common.
Suggests that different organisms living in similar environments could evolve similar traits
Ex = North American muskrat and the South American coypu
Ex = Beaver in North America and capybara in South America
3. ______- study of organisms at an early stage of development
Similarities in the ______of many organisms suggest an evolutionary relationship (common ancestor).
4. ______- body parts of different organisms that have the same basic structure.
Develop from the same embryonic tissues but have different mature forms
Similarities in body parts suggest a ______ancestor
Ex: Similar bones in whale flipper and a human hand
5. ______- body parts that are reduced in size and have no function
Suggests that as body part was no longer needed in environment they were lost
B. Ex: human appendix or hip and leg bones in snakes
6. ______- Because of______, breeders are able to produce a wide range of plants and animals that look very different from their ancestors
______- Differences among individuals of the same species (ex: no 2 human beings look exactly like unless they are identical twins)
______- due to mutations (changes in a gene). Remember not all mutations are harmful!
Further evidence used in modern science / ______- All organisms share similar biochemistry
- All organisms have ______& ______
- All organisms use ______as cellular energy
- Many organisms use many of the same ______
Darwin’s Natural Selection / ______- Works much like artificial selection, but the environment “selects” the best traits.
A. Causes Survival of the Fittest
B. ______is a result of______.
Fitness = the ability of an individual to survive
Adaptation = an inherited characteristic that increases the chance of survival