Unit 1: Evolution - Evidence Flashcards
What do layers of sedimentary rock contain?
fossils
What do new layers of sedimentary rocks cover?
Older ones, creating a record over time
What do fossils within layers show?
That a succession of organisms have populated Earth throughout a long period of time
What are fossils?
Any preserved remains or traces of an organism or its activity
What are many fossils of?
Such hardened body parts as bone
What is fossilization?
The process by which traces of past organisms become part of sedimentary rock layers or, more rarely, hardened tar pits, volcanic ash, peat bogs, or amber
What is paleontology?
The scientific study of fossil remains Paleao = old/primitive; onto = of being; logy = the study of
What is a fossil record?
A record showing us that today’s organisms descended from ancestral species
What is the evolutionary change in horses?
- Increase in size,
- loss of toes
- increase in size of molars
What is radiometric dating?
a technique used to date rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates
What is the evolution of birds?
Archaeopteryx
lived about 150 mya; links reptiles & birds
What is the evolution of land animals?
- 2006 Fossil Discovery of Early Tetrapod
- “Tiktaalik”
- “missing link” from sea to land animals
- from swimming (0 legs) to walking (4 legs)
What happens during artificial selection?
Humans “improve” domesticated plant and animal species for thousands of years of selection
What does artificial selection involve?
Selecting offspring with desirable traits as breeding stock for succeeding generations
What are examples of organisms used in artificial selection?
Farm animals
Cats, and dogs
Flowering plants
Crops
