My AP Biology Thoughts

Episode 7

Welcome to My AP Biology Thoughts podcast, my name is Victoria and I am your host for episode #7 called Unit 7 Evolution: Evidence of Evolution. Today we will be defining the 4 Pieces of Evidence for Evolution, giving examples of each, and making connections to the unit of evolution. 

Segment 1: Introduction to Evidence of Evolution

What is evolution?

• A change in the allelic frequencies of a gene pool 
• Continuous 

4 Pieces of Evidence of Evolution - 

1. Fossil Record
2. the preserved remains of traces of any organisms from the remote past, included both discovered and undiscovered
3. Only the hard parts of an organism are preserved 
4. Fossil evidence can be either
5.  Direct (body fossils): bones, teeth shells, leaves
6. Indirect (trace fossils): footprints, tooth marks, tracks, burrows
7. Like timeline, different kinds of organisms do not occur randomly but are found in rocks in a consistent order, this is known as the law of fossil succession 
8. It is incomplete, and requires an unusual combination of specific circumstances for it to occur, creating many gaps in the fossil record 
9. Biogeography:
10. Organisms located in one area of the planet are closely related than those found in other parts of the planet
11. It describes the distribution of organisms, over geographical areas, both in the past and present
12. Comparative Anatomy:
13. The comparison of the anatomic features of different species
14. 2 Key types of structures that support this
15. Homologous structures
16. Demonstrate a similar underlying anatomy due to shared evolutionary origin, but have evolved into a variety of distinct forms or speciation due to the presence of different selective pressures
17. The more similar the homologous structures between the two species are, the more closely related they are likely to be
18. Adaptive radiation through divergent evolution, as similar basic organisms have been adapted to suit various environmental niches 
19. Analogous structures