Ch. 13: Evidence of Evolution Flashcards
What is paleontology?
Study of fossils and other evidence of past life
When does a fossil fail to form?
Organism is eaten or microbes, water, or bacteria may break it down
Two ways fossils may be preserved:
Freezing or burial in sedimentary layers
Types of fossils? (3)
Bone preserved, molded, or amber
3 Reasons why fossil records are incomplete:
- Organism never left a fossil
- Movement of tectonic plates
- Hard to reach places
Relative dating vs. Radioactive dating:
Relative: comparing fossil age to other fossils next to it or the rock its preserved in
Radioactive: fossils are same age as rock so the radioactive measurements are recorded
How are half-lives linked to unstable radioactive isotopes?
As half-life increases, radioactive isotopes decrease
What is a radioactive isotope and how is decay related to it?
The radioactive isotope is the unstable Carbon 14 and it decays because during the organism’s life, C14 is replaced but after death it is no longer replaced.
What is the theory of plate tectonics, how does it relate to biography, and what are some evidence to support the evidence of plate tectonics?
- The continents were once combined as one land, but separated and moved to where it is now.
- Related to biography because organisms evolved since Pangaea based on environment
- Biogeography is evidence. Fossils of the same organisms are distributed across several continents because the continents were together.
Describe Wallace Line and relations to trenches:
Placentals on one side and marsupials on the other side;
Type of organism that carries pouch for offspring:
Marsupials
Homologous structures definition:
similar structures (such as arms of various organisms)
Vestigial structures definition:
structure that does not work
Analogous body parts:
Similar structures, but no common ancestor
Convergent Evolution:
Similar adaptations, no connection in ancestry
