What is Evolution?

1. What is Evolution? The process of change in the traits of populations over time. Process by which species' characteristics change over generations. Traits must have genetic basis. Evolution does not occur within an individual. Evolution does not occur within a generation.

2. What is Evolution? Evolution occurs primarily through natural selection Natural Selectionis the process that determines which individuals within a species will reproduce and pass their genes to the next generation. Proposed by Charles Darwin in his book “On the Origin of Species” published in 1859

3. Genes— Distinct pieces of DNA that determine an individual’s characteristics. Population—All organisms of the same kind found within a specific geographic region. (have the potential to interact) Species— Those organisms potentially capable of reproducing naturally among themselves, and producing viable offspring.

4. Natural selection can occur when: * Individuals within a species show genetically determined variation in traits -this variation makes some individuals better at surviving and reproducing than others • * More offspring are produced than survive to reproduce *Offspring with a particular trait survive better than do those without that trait *Over several generations, the frequency of that trait increases in the population

5. Potential for rapid reproduction Relatively constant resources and population size over time Competition for survival and reproduction Variability in structures and behaviors NATURAL SELECTION: On the average, the better adapted organisms leave the most offspring Some variability is inherited EVOLUTION: The genetic makeup of the population changes over time, driven by natural selection Observation Conclusion based on observation FLOW CHART FOR EVOLUTION

6. Evolution in action Pepper Moths in England two forms: light and dark Prior to 1845, most moths light colored • Light colored ones could blend in with lichens on trees

7. Evolution in action Pepper Moths in England Increasing pollution led to soot-covered trees without lichens • Light colored moths easy for birds to see on soot-covered tree, dark colored moths harder to see By 1950, most moths black

8. Before 1845 1950 Environment changes, now more black moths and fewer white moths survive to adulthood Several more generations later Several generations later Several more generations later TIME

9. Evolution in action Resistance to herbicides

10. Evolution in action Resistance to antibiotics

11. Evolution does not just happen on long time scales • Evolution is important for real-word issues: agricultural, conservation, health * Disease dynamics * Invasive species issues * Antibiotic and pesticide/herbicide resistance

12. Red Queen Hypothesis Lewis Carroll's Through the Looking Glass: “in this place it takes all the running you can do, to keep in the same place." Coevolution: When two or more species interact closely they can influence each other’s evolutionary direction. In tightly coevolved interactions, evolutionary change in one species will lead to evolutionary change in other or the second species may go extinct. Example: host / parasite coevolution

13. Abiotic – Non-living factors Biotic – living portion of the environment What are some biotic factors that contribute to this differential survival and reproduction? Interactions among organisms 1. Predation 2. Competition 3. Parasitism 4. Commensalism 5. Mutualism

14. Interactions among organisms 1. Predation(positive for consumer, negative for prey) One animal consumes another

15. Types of predators Active predators: chase & overpower prey Sit-and-wait predators: motionless until prey close enough to strike

16. Sit-and-wait predator Antlion

17. HOW DO VULNERABLE ORGANISMS PROTECT THEMSELVES? The bombardier beetle The best defense is a good offense - chemical warfare A monarch caterpillar

18. Many prey items have traits that reduce predation Cryptic Coloration: blend in with environment

19. A moth The leafy sea dragon A desert plant Florida treehopper insects

20. Cryptic Coloration a.k.a. camouflage Nightjar bird The sand dab Living stone plants

21. Warning or aposematiccoloration The South American poison arrow frog

22. Many prey items have traits that reduce predation Warning Coloration: aposematic coloration - conspicuous to convey threat

23. Startle coloration caterpillar larva of the swallowtail butterfly the false-eyed frog The peacock moth

24. ADAPTIVE COLORATION AND MIMICRY Types of Mimicry • 1. Batesian mimicry: mimic species resemble an unplatable or venomous species (the model) • 2. Mullerian mimicry: all mimic species have similar warning coloration. All mimics are usually toxic or harmful and function as both model and mimic.

25. Batesian Mimicry: defenseless species (mimic) is protected from predation by its resemblance to a species that is dangerous (the model); Henry Walter Bates was an English biologist who described a type of mimicry in tropical butterflies in the 1850's. fly (bee mimic) bumble bee

26. mountain king snake coral snake viceroy monarch butterfly

27. Naïve Blue Jay and a Monarch Butterfly

28. Batesian Mimicry in Plants: Stinging Nettle (model) and the Yellow Archangel (the mimic)

29. Visual and behavioral mimicry the snowberry fly a jumping spider

30. Mullerian Mimicry: Two or more distasteful or harmful organisms resemble each other; each serve as model and mimic. Fritz Muller was a German zoologist who described a different type of mimicry in 1878.

31. Interactions among organisms 1. Predation • Predator benefits (+) from food • Prey is harmed (-) by being eaten Predation is a (+ / - ) relationship

32. Interactions among organisms 2. Competition Competition: organisms compete for the same limited resource Ex. light, food, mates, habitat, etc. Competition is a (- / - ) relationship

33. Intraspecific competition— Members of same species competing for resources Beetle vs. Beetle Fungus vs. Fungus

34. Interspecific competition: • Members of different species competing for resources • May lead to competitive exclusion

35. Interactions among organisms 3. Parasitism One organism (parasite) living in or on another organism (host), from which it derives nourishment Ex. Tapeworm Parasitism is a (+ / - ) relationship

36. 3. Parasitism (+,-) • Ectoparasites—Live on host’s surface • (e.g., Fleas, lice, some molds)

37. 3. Parasitism (+,-) • Endoparasites—Live inside host. • (e.g., worms, protozoa, bacteria, fungi) Ex. Heartworm

38. Parasitoid

39. Nest Parasitism Adult cowbirds don’t build nests Cowbird Common Yellow-throat

40. Vectors: animals that carry parasite from one host to another Examples: Malaria, Lyme Disease, West Nile Virus, Bubonic Plague Malaria carrying mosquito

41. Interactions among organisms 4. Commensalism —One organism benefits, while the other is unaffected. Remora and shark Commensalism is a ( + / 0 ) relationship

42. 4. Commensalism(+,-)

43. Interactions among organisms 5. Mutualism- Both species benefit. Acacia and ants *Tree provides sugar solution that the ants eats *Ants defends tree against grazers

44. 5. Mutualism(+,+)

45. Summary of 5 major Interactions Individual 1 Individual 2 Predation + - Competition - - Parasitism + - Commensalism + Neutral Mutualism + +

46. How have people change these interactions? 1) Introduced species 2) Habitat destruction Introduction of novel predators and parasites can devastate natural communities.

47. Over 2,000 species of birds have gone extinct on islands as a result of habitat loss and the introduction of predators and parasites. Hawaii: Habitat loss, malaria, rats and mongoose

48. Points to know: Know what evolution is and how is operates. Understand coevolution. Know the 5 main types of species interactions. Understand who benefits from each type of interaction (one or both participants) Understand how humans may influence these interactions.

49. On-Line Sources of Information used to create this presentation • http://www.uta.edu/biology/alie/1282/Lecture2.ppt#260,6,SUMMARY OF EVOLUTION • http://www.life.uiuc.edu/ib/105/lectures/06_EcolInter.ppt#429,1,Slide