1. Chapter 4 Evolution and Biodiversity

2. ORIGINS OF LIFE  1 billion years of chemical change to form the first cells, followed by about 3.7 billion years of biological change. Figure 4-2

3. Biological Evolution  This has led to the variety of species we find on the earth today. Figure 4-2

4. How Do We Know Which Organisms Lived in the Past?  Fossils  chemical analysis  cores drilled out of buried ice  DNA analysis. Figure 4-4

5. EVOLUTION, NATURAL SELECTION, AND ADAPTATION  Macroevolution  Microevolution - brought about by mutation, natural selection, gene flow, & genetic drift  Gene pool  Differential reproduction  Directional Selection  Disruptional Selection  Stabilizing Selection

6. Natural Selection and Adaptation: Leaving More Offspring With Beneficial Traits  Three conditions necessary for biological evolution: Genetic variability, traits must be heritable, trait must lead to differential reproduction. Genetic variability, traits must be heritable, trait must lead to differential reproduction.

7. Coevolution: A Biological Arms Race  Predator and prey species  Batesian Mimicry (1 bad, 1 not)  Mullerian Mimicry (many poisonous animals are brightly colored)

8. GEOLOGIC PROCESSES, CLIMATE CHANGE, CATASTROPHES, AND EVOLUTION  The movement of solid (tectonic) plates making up the earth’s surface, volcanic eruptions, and earthquakes can wipe out existing species and help form new ones. The locations of continents and oceanic basins influence climate. The locations of continents and oceanic basins influence climate. The movement of continents have allowed species to move. The movement of continents have allowed species to move.

9. Fig. 4-5, p. 88 135 million years ago Present 65 million years ago 225 million years ago

10. Climate Change and Natural Selection  Changes in climate throughout the earth’s history have shifted where plants and animals can live. Figure 4-6

11. ECOLOGICAL NICHES AND ADAPTATION  Each species in an ecosystem has a specific role or way of life. Fundamental niche: the full potential range of physical, chemical, and biological conditions and resources a species could theoretically use. Fundamental niche: the full potential range of physical, chemical, and biological conditions and resources a species could theoretically use. Realized niche: to survive and avoid competition, a species usually occupies only part of its fundamental niche. Realized niche: to survive and avoid competition, a species usually occupies only part of its fundamental niche.

12. Generalist and Specialist Species: Broad and Narrow Niches  Generalist species tolerate a wide range of conditions.  Specialist species can only tolerate a narrow range of conditions. Figure 4-7

13. SPOTLIGHT Cockroaches: Nature’s Ultimate Survivors  350 million years old  3,500 different species  Ultimate generalist Can eat almost anything. Can eat almost anything. Can live and breed almost anywhere. Can live and breed almost anywhere. Can withstand massive radiation. Can withstand massive radiation. Figure 4-A

14. Specialized Feeding Niches  Resource partitioning reduces competition and allows sharing of limited resources. Figure 4-8

15. Evolutionary Divergence  Each species has a beak specialized to take advantage of certain types of food resource. Figure 4-9

16. SPECIATION, EXTINCTION, AND BIODIVERSITY  Speciation: A new species can arise when member of a population become isolated for a long period of time. Reproductive isolation: Reproductive isolation: Temporal isolation Temporal isolation Behavioral isolation Behavioral isolation Geographic isolation Geographic isolation

17. Geographic Isolation  …can lead to reproductive isolation, divergence of gene pools and speciation. Figure 4-10

18. Extinction: Lights Out  Background extinction  Mass Extinction  Adaptive radiation  Gradualism  Punctuated Equilibrium  Fitness  The golden toad of Costa Rica’s Monteverde cloud forest has become extinct because of changes in climate. Figure 4-11

19. Fig. 4-12, p. 93 Tertiary Bar width represents relative number of living species EraPeriod Species and families experiencing mass extinction Millions of years ago Ordovician: 50% of animal families, including many trilobites. Devonian: 30% of animal families, including agnathan and placoderm fishes and many trilobites. 500 345 Cambrian Ordovician Silurian Devonian Extinction Paleozoic Mesozoic Cenozoic Triassic: 35% of animal families, including many reptiles and marine mollusks. Permian: 90% of animal families, including over 95% of marine species; many trees, amphibians, most bryozoans and brachiopods, all trilobites. Carboniferous Permian Current extinction crisis caused by human activities. Many species are expected to become extinct within the next 50–100 years. Cretaceous: up to 80% of ruling reptiles (dinosaurs); many marine species including many foraminiferans and mollusks. Extinction Triassic Jurassic Cretaceous 250 180 65 Extinction QuaternaryToday

20. GENETIC ENGINEERING AND THE FUTURE OF EVOLUTION  We have used artificial selection to change the genetic characteristics of populations with similar genes through selective breeding.  We have used genetic engineering to transfer genes from one species to another. Figure 4-15

21. Genetic Engineering: Genetically Modified Organisms (GMO)  GMOs use recombinant DNA genes or portions of genes from different organisms. genes or portions of genes from different organisms. Figure 4-14