1. SWBAT explain ways new species are created.
Objective:
SWBAT explain ways new species are created.

2. Speciation Notes
Chapters and 19

3. Cabbage Lateral buds Terminal bud Flowers and stems Brussels sprouts
Figure 13.2
Cabbage
Lateral
buds
Terminal bud
Flowers
and stems
Brussels sprouts
Broccoli
Figure 13.2 Artificial selection: different vegetables produced as humans have selected for variations in different parts of the wild mustard plant
Stem
Leaves
Kale
Kohlrabi
Wild mustard 3

4. Disruptive selection Figure 13.13
Figure Three possible effects of natural selection on a phenotypic character (part 3)
Disruptive selection 4

5. A group of organisms that can interbreed and produce viable, fertile offspring.
What is a Species?

6. The process by which one species gives rise to two or more species.
It requires some type of separation between the populations.
What is Speciation?

7. Separation that is often caused by habitat location.
Different selection pressures from the new environment.
Mating is impossible - if meeting again
Steps to Speciation

8. Reproductive Isolation
Pre-zygotic – before mating is completed
Post-zygotic – after mating is completed
Reproductive Isolation

9. Pre-zygotic Geographic (Location) Temporal (Time)
Behavioral (Mating Rituals)
Structural (Reproductive Organs)
Gametes (Number of Chromosomes)
Pre-zygotic

11. Temporal Isolation
Late Winter
Late Summer

12. Structural differences prevent mating
Example:
Genital openings (arrows) not aligned  No Mating

13. Hybrid offspring dies
Hybrid offspring can’t reproduce
Post-zygotic

14. Sheep x Goat = Offspring will die before birth

17. Adaptive Radiation An example of adaptive radiation –
these species all diverged from a
common ancestor (founder species)
FOUNDER SPECIES

19. Other Types of Evolution & Selection Methods
Convergent Evolution & Coevolution
Sexual Selection

20. Organisms that are not closely related resemble each other because they have responded to similar environments.
Convergent Evolution

21. Coevolution
two (or more) species both adapt to work together

22. Sexual Selection
Females and Males often show different characteristics
Some characteristics are selected for within the species
Teaching Tips
Challenge your students to distinguish between natural selection, sexual selection, and artificial selection. One criterion for comparison is the nature of the selective environment. In natural selection, the interaction is between the organism and its immediate environment. In sexual selection, competition occurs within a species for access to mates. In artificial selection, humans are an important component of the environment, favoring traits of human interest.
© 2012 Pearson Education, Inc. 22

23. Figure 13.14A
Figure 13.14A Extreme sexual dimorphism (peacock and peahen) 23

24. Figure 13.14B
Figure 13.14B A contest for access to mates between two male elks 24

25. Figure 13.14C
Figure 13.14C A male gray tree frog calling for mates 25

26. Biological Evidence for Inheritance

28. Biological Molecules
Biological molecules such as RNA, DNA, and proteins are used by all living organisms, indicating a common evolutionary history.