LESSON # 23

1. LESSON # 23 THE OUTCOMES OF EVOLUTION: Macroevolution

2. MICROEVOLUTION MACROEVOLUTION EVOLUTION Any genetically based phenotype change in a population of organisms over successive generations. A change of allele frequencies in a population over a relatively short period of time. No new species are originated. Evolution that results in the formation of new species.

3. How Do New Species Arise? One specie can be transformed into another in the process called speciation. The development of new species through evolution. Speciation: What brings this branching evolution? Macroevolution Microevolution Common ancestor

4. Microevolution: A change of allele frequencies in a population over a relatively short period of time. After enough time, should the two population find them- selves geographically reunited, they may no longer freely interbreed. At that point, they are separated species. Speciation has occurred.

5. What Could Drastically Reduce Interbreeding? Geographical separation is the most important factor in getting speciation going. When geographical barriers divide a population and the resulting populations then go on to become separate species, what has occurred is Allopatric Speciation. Allopatric Speciation Speciation Sympatric Speciation

6. Examples of Allopatric Speciation Millions of years ago The east and west population came back together in Southern California, but could no longer interbreed (or produce infertile hybrid offspring).

7. Geographic Separation + Geographic Separation by itself No interbreeding Interbreeding Geographical separation can not produce speciation by itself. Reproductive isolating mechanisms no speciation Speciation Following geographic separation, the two populations of the same species must then undergo physical or behavioral changes that will keep them from interbreeding, should they ever be reunited.

8. Reproductive Isolating Mechanisms Any factor that, in nature, prevents interbreeding between individuals of the same species or of closely related species. Extrinsic Intrinsic Geographic Separation 1- Ecological Isolation 2- Temporal isolation 3- Behavioral Isolation 4- Mechanical Isolation 5- Gametic isolation 6- Hybrid Inviability (Infertility)

9. Intrinsic Isolating Mechanisms

11. Sympatric: “of the same country” Allopatric: “of other country” Intrinsic Reproductive Isolating Mechanisms can develop between two populations in the absence of any geographic separation of them. Allopatric Speciation: When geographical barriers divide a population and the resulting populations then go on to become separate species. Sympatric Speciation: Any speciation that does not involve geographic separation.

12. The Categorization of Earth’s Living Things

13. How many species are in the earth? The lowest estimate: About 4 million species The higher end estimate: From 10 to 15 million species. Every species may have different common names in different places. To prevent the confusion that can result from having several common names, species are not named by their common names but by scientific names.

14. Felis is a genus of cats. The second name is the species of cat. Chinese Mountain Cat, Felisbieti Jungle Cat, Felischaus Pallas's Cat, Felismanul Sand Cat, Felis margarita Black-footed Cat, Felisnigripes Wildcat, Felissilvestris Domestic Cat, Felissilvestriscatus BINOMIAL NOMEMCLATURE Scientific names for species has two parts: 1- The first part is the genus, which designates a group of individuals who are closely related but still are separated species 2- The second part designatesspecies

15. Genus canis Canis adustusCanis aureus (jackal)Canis dirus (extinct)Canis latransCanis lupus (wolf, domestic dog)Canis mesomelasCanis rufusCanis simensis Canis lupus Canis aureus Canis lupus familiaris

16. Plantae Archaea Fungi Bacteria Animalia Eukarya Protista Taxonomic Classification A method of classifying organisms based on 8 categories called taxons. 1- Domain 2- Kingdom 3- Phylum 4- Class 5- Order 6- Family 7- Genus 8- Species

17. Plantae 1- Domain 2- Kingdom 3- Phylum 4- Class 5- Order 6- Family 7- Genus 8- Species Fungi Archaea Animalia Bacteria Protista Eukarya

18. Species are named and classified according to how closely they are related. Systematics: It is the field of Biology that is concerned with the diversity and relatedness of organisms. Systematics tries to establish the truth about who is more closely related to whom by studying the evolutionary history of organisms. 1- Classical Taxonomy Classification of Living Things 2- Cladistics

19. 1- Classical Taxonomy It is based in the physical form or “morphology” of the animals in questions, as preserved by fossil record, and comparing it to the morphology of modern animals.

20. 2- Cladistics It is based in the differences between ancestral characters and derived characters.

21. - Ancestral characters: Characters existing in a common ancestor - Derived characters: Characters which are unique to the organisms descended from a common ancestor

22. Classical Taxonomic Classification Cladistic Taxonomic Classification It is based in the physical form or “morphology” of the animals in questions, as preserved by fossil record, and comparing it to the morphology of modern animals. It is based in the differences between ancestral characters and derived characters.