What exactly is evolution?

1. What exactly is evolution? Evolution is the biological change process by which descendants come to differ from their ancestors. Or, simply: gradual change in organisms over time

2. Theories of geologic change set the stage for the evolutionary theory. • There were three theories of geologic change. • Catastrophism • Gradualism • Uniformitarianism Hey You! Row 3, Seat 3 … Yeah You! What type of species isolation is this?

3. Catastrophism • Natural disasters such as floods and volcanic eruptions have happened often during Earth’s long history • These events shaped landforms and caused species to become extinct in the process

4. Gradualism • Landforms result from slow changes over a long period of time • Creation of canyons, laying down of soil

5. Uniformitarianism is the prevailing theory of geologic change. • Geologic processes that shape Earth are uniform through time

6. Pssssssssssssssssttttt.. • Hey all of you fine looking Biology students!! I need a recap of this evolution stuff! Can you jot one word, yes just one word that can explain each of these terms? • Catastrophism • Gradualism • Uniformitarianism

7. Evidence for evolution came from several sources.( Fossils, Geography, Embryology, and Anatomy ) • Fossils provide evidence of evolution. • Fossils in older layers are more primitive than those in the upper layers.

8. island species most closely resemble nearest mainland species • populations can show variation from one island to another • Biogeography is the study of the distribution of organisms around the world • The study of geography provides evidence of evolution.

9. Larva Adultbarnacle Adult crab • identical larvae, different adult body forms • similar embryos, diverse organisms • Embryology provides evidence of evolution.

10. Molefoot Batwing Human hand • Homologous structures are similar in structure but different in function. • Homologous structures are evidence of a common ancestor. • The study of anatomy provides evidence of evolution.

11. Bat wing Fly wing • The study of anatomy provides evidence of evolution. • Analogous structures have a similar function. • Analogous structures are not evidence of a common ancestor. Row 4, Seat 2 Is this Divergent or Convergent Evolution? Umm Why?

12. Structural patterns are clues to the history of a species. • Vestigial structures are remnants of organs or structures that had a function in an early ancestor. • Ostrich wings are examples of vestigial structures. Ostriches use their wings for balance not flight!

13. Umm….Need a little Help!Lets Talk, Can we?????? • How can I remember these terms on my test? • Homologous Structures • Analogous Structures • Vestigial Structures

14. Wisdom teeth are a third set of molars that usually appear in humans between the ages of 17 and 25, and often need removing because they crowd our other teeth. Explain why wisdom teeth are vestigial structures. Use your own paper to respond and turn in when you are finished.

15. Early scientists proposed ideas about evolution. • Linnaeus: classification system from kingdom to species • Buffon: species shared ancestors rather than arising separately • E. Darwin: more-complex forms developed from less-complex forms • Lamarck: environmental change leads to use or disuse of a structure

16. Then there was Darwin. • Influenced by Lyell’s views of gradual geologic change • 1831 - HMS Beagle traveled to South America. Conducted studies of evolution on the Galapagos Islands • Found much evidence to support Lyell’s views • Formulated his own opinions

17. Galapagos Islands … Let’s go!! Pack your bags!! Take a NOVA Galapagos Island Tour

18. Darwin observed differences among island species. • Variation is a difference in a physical trait. • Galápagos tortoises that live in areas with tall plants have long necks and legs. • Galápagos finches that live in areas with hard-shelled nuts have strong beaks.

19. Do you see any variation in this population of King Penguins? How might this population of penguins change if Antarctica suddenly got much warmer?

20. Species may somehow be able to adapt to their surroundings… • An adaptation is a feature that allow an organism to better survive in its environment. • Species are able to adapt to their environment. • Adaptations can lead to genetic change in a population.

21. Darwin observed fossil and geologic evidence supporting an ancient Earth. • Darwin found fossils of extinct animals that resemble modern animals. • Darwin found fossil shells high up in the Andes mountains. Shells in the mountains …. No possible way!! Who can possibly explain that??? Raise your hands 

22. He saw land move from underwater to above sea level due to an earthquake. • Darwin’s observations supported Lyell’s theory that daily geologic processes can add up to great change over a long period of time. • Darwin extended his observations to the evolution of organisms.

23. Darwin proposed natural selection as a mechanism for evolution. Star-nosed mole Snout’s 22 fingerlike rays can touch up to 12 objects in just one second!

24. Several key insights led to Darwin’s idea for natural selection. • Darwin noticed a lot of variation in domesticated plants and animals. • Traits that weren’t in their wild relatives • In order for artificial or natural selection to occur, the trait must be heritable. • Heritability is the ability of a trait to be passed down.

25. Artificial selection is the process by which humans select traits through breeding. Natural selection is a mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals. neck feathers crop tail feathers Artificial Vs. Natural Selection Artificially Bred Pigeons

26. VARIATION OVERPRODUCTION ADAPTATION DESCENT withMODIFICATION Natural selection explains how evolution can occur. • There are four main principles to the theory of natural selection. • Variation • Overproduction • Adaptation • Descent with modification

27. Use your Biology Book (p. 306) to define each main principle to the theory of natural selection. • Variation: • Overproduction: • Adaptation: • Descent with Modification: Inherited trait that is selected for over time because it allows organisms to better survive in their environment. Having many offspring raises the chance that some will survive, it increases competition for resources. A certain variation allows an individual to survive better than other individuals it competes with. Species with adaptations suited for survival and reproduction; these adapataions will continue in future generations.

28. Survival of the Fittest? • Fitness is the measure of survival ability and ability to produce more offspring. • Jaguars with larger teeth and jaws have a higher fitness than other jaguars in a population. • Other jaguars reproduce less because they were less fit.

29. Natural selection acts on existing variation. five digits wrist bone • Natural selection can act only on traits that already exist. • Structures take on new functions in addition to their original function. The panda’s wrist bone also functions like a thumb.

30. New technology is furthering our understanding of evolution.

31. Fossils provide a record of evolution. • Paleontology is the study of fossils or extinct organisms.

32. Paleontology provides evidence to support evolution.

33. Molecular and genetic evidence support fossil and anatomical evidence. • Two closely-related organisms will have similar DNA sequences.

34. Evolution unites all fields of biology. • Scientist from many fields contribute to the understanding of evolution. • The basic principles of evolution are used in many scientific fields.