1. 1. Which describes natural selection. a
1. Which describes natural selection? a. Some live and some die in each generation b. Only the largest and strongest survive c. Random assortment of genes results in better characteristics in the following generations d. The best adapted individuals survive and reproduce, contributing the most to the next generation 2. Which of the following is NOT one of the premises on which evolution by natural selection is based? a. Organisms usually produce many more offspring than the environment can support. b. Most natural populations remain approximately the same size through time. c. Adaptations help organisms survive in a particular environment. d. Hereditary differences can be passed on to offspring.

2. Good Things!!

3. Evidence for evolution
Embryos
Molecules in organisms
Structures
Fossils

4. Embryology
The study of how organisms develop. An embryo is an animal or plant in its earliest stages of development.
The embryos of some species are difficult to tell apart, and the longer they are similar, the more related they are.

5. Embryology

6. Molecular
1. The same biochemical building blocks, such as amino acids and nucleotides, are found in all organisms, from bacteria to plants and animals.
2. DNA and RNA determine the development of all organisms.
3. The similarities and differences between DNA are compared. The fewer the differences, the closer related.

7. Structural
Vestigial
Analogous
Homologous

8. Vestigial Structures
Body parts that have lost their use over time. Suggest that an organism changed from using the structure to not using the structure or using it for a different purpose.
**For example, most birds need their wings to fly. But the wings of an ostrich have lost their original use.

9. Vestigial Structures

10. Convergent vs Divergent

11. Divergent
A common ancestor evolves into new species, which continue to evolve and become less and less alike over time due to differences in the demands driven by the environment.

12. Divergent

13. Divergent
Shown by homologous structures:
Structures or traits that are inherited by two different organisms from a common ancestor. They have the same structure but not always the same function.

14. Divergent

15. Convergent
When two separate groups of animals evolve to have similar structures

16. Convergent
Often, two species face a similar problem or challenge. Evolution may then shape both of them in similar ways.
***Both are extinct animals and both of them have saberteeth...but are they homologous??
Thylacosmilus, a marsupial mammal
Smilodon, saber-toothed cat, which is a placental mammal

17. Convergent
Convergent evolution is shown by analogous structures: Structures or traits that are adapted separately.
They have the same function but not always the same structure.

18. GAME TIME!
Apply your knowledge.....
Homology or Analogy??

19. Dolphins and Sharks...... both have a streamlined body shape with a triangular fin on the back

20. They are ANALOGOUS....

22. What is a Cladogram?
Cladogram- A branching diagram showing the relationship between a number of species.

23. Cladogram
CLADISTICS is form of analysis that looks at features of organisms that are considered "innovations", or newer features that serve some kind of purpose.

24. What is a cladogram?