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What is a homologous structure? How are these evidence for evolution?

Biology Journal 4/30/2014. What is a homologous structure? How are these evidence for evolution?. Biology Journal 12/12/2013. Compare and contrast intraspecific competition and interspecific competition in a Venn diagram. What kinds of competition is going on in these pictures?.

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What is a homologous structure? How are these evidence for evolution?

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  1. Biology Journal 4/30/2014 What is a homologous structure? How are these evidence for evolution?

  2. Biology Journal 12/12/2013 Compare and contrast intraspecific competition and interspecific competition in a Venn diagram. What kinds of competition is going on in these pictures?

  3. Biology Journal 12/10/2013 What could be some things that organisms compete for? Who do they compete against? What could happen if there is too much competition?

  4. Biology Journal In terms of natural selection, why did the dinosaurs go extinct?

  5. Biology Journal What is your reaction to this data? How do you think the data would look in 50 years? How do you think the data would look in 500 years?

  6. Biology Journal What could be some differences between artificial selection and natural selection? What could be some of the end results on the creature that is “selected” in these two different ways?

  7. Biology Journal What could be some examples of environmental pressures? What is the impact of these on natural selection?

  8. Biology Journal What are the 4 steps of natural selection? How does this picture show each of these steps?

  9. Biology Journal Do you think that the human race is still evolving? Why or why not? (there is totally no specific, right answer, just a good explanation of your answer)

  10. Biology Journal 5/1/2014 Bacteria are getting stronger all the time! Explain why this is happening in terms of natural selection. What could be done to slow this process down?

  11. Biology Journal 2/28/2014 + = What must 2 organisms be able to do in order to be considered the same species? What could be some problems with this definition?

  12. Species Problem Populations move. Species evolve. DNA changes. Constantly! + = • Donkey • Equusafricanus, aka “ass” • 64 chromosomes • Excellent at pulling or carrying weight • Mule • No species name! • Sterile! (can’t reproduce) • 63 chromosomes • Often has useful qualities of both horses and donkeys • Horse • Equusequus • 62 chromosomes • Fast, easy to train for a variety of tasks (riding, racing, pulling a carriage, warfare) + = • Grizzly Bear • Ursusarctos • 74 chromosomes • Lives in North American temperature regions • Polar Bear • Ursusmaritimus • 74 chromosomes • Lives in Arctic regions of Northern hemisphere • Grolar Bear • No species name! • Can reproduce! • 74 chromosomes • Found in wild and in captivity

  13. Evolution

  14. What could be some things that limit population size?

  15. Environmental Pressure: Anything (living or nonliving) in the environment that decreases an organism’s chances of surviving or reproducing.What could be some examples of this? Predators Space / Habitat Competition (Population density) Diseases

  16. What can happen if environmental pressure gets too great? The population must move to another area (emigrate), or die off (and can eventually go extinct in that area)

  17. What could happen if environmental pressure is too little? The population size grows exponentially until it reaches or exceeds the carrying capacity (the maximum number of organisms that can survive in an area)

  18. Evolution is the cumulative change in the heritable characteristics of a population. Evolution is the cumulative change in the heritablecharacteristics of a population. Changes happen gradually, and accumulate over many generations Traits carried on genes (DNA) Can be inherited (passed form parents to offspring) A species, which is a large group interbreeding of organisms How could you possible get something as complex as an eye, or flight, or hands, or anything evolve slowly over time? We have the evidence in living and fossilized organisms.

  19. All organisms have a common ancestry. Homologous structures are an evidence of this. The same structure has been passed down through the DNA and evolved to different functions. These animals all must be related to a single species in the past.

  20. Why do all of these completely different organs have exactly the same bone arrangement? Because a common ancestor had those bones!

  21. We also find fossils of all of the intermediate ancestors of all of these creatures as fossils!

  22. Natural Selection has 4 Basic steps: 1. More organisms are born than survive. Game = Frogger Difficulty Setting = Epic

  23. Natural Selection has 4 Basic steps: 2. A population has genetic variation

  24. What is the difference between sexualand asexualreproduction? Which one introduces more diversityin the gene pool of a population?

  25. Natural Selection has 4 Basic steps: 3. Organisms struggle to survive against environmental pressures.

  26. Natural Selection has 4 Basic steps: 4. Organisms with advantageous traits are more likely to survive and pass on those traits.

  27. A story of natural selection… In the 1800s, in the forests of England, there lived an insect called the peppered moth. There were two phenotypes (appearances) of this insect.

  28. Tutorial and Game with Peppered Moths: http://www.techapps.net/interactives/pepperMoths.swf

  29. A story of natural selection… The light colored moths made up 99% of the population. Can you explain why in terms of natural selection?

  30. A story of natural selection… Then, the industrial revolution happened in England. And with it came a lot of unregulated pollution. When you don’t vote, your standard of living tends to get worse.

  31. Tutorial and Game with Peppered Moths: http://www.techapps.net/interactives/pepperMoths.swf

  32. Realizing the damage that was being done, reforms were eventually passed to limit pollution. The forest returned to the way is was before. What do you think happened to the peppered moth population?

  33. Antibiotic resistant bacteria is a dangerous lesson in natural selection

  34. Antibiotic resistant bacteria is a dangerous lesson in natural selection

  35. Antibiotic resistant bacteria is a dangerous lesson in natural selection

  36. Antibiotic resistant bacteria is a dangerous lesson in natural selection

  37. Antibiotic resistant bacteria is a dangerous lesson in natural selection Big Problems!

  38. When we use pesticides on crops, they work great for a few years, and then become useless. Can you explain why?

  39. Humans can manipulate and evolution by controlling who reproduces and with whom. This is called artificial selection. Artificial Selection Through thousands of years of artificial selection, humans turned wolves, majestic symbols of wilderness and independence, into helpless, dumb poodles.

  40. What did we artificially select these dogs to do? Greyhound Golden Retriever Siberian Husky Bloodhound German Shepherd St. Bernard Pit Bull Chihuahua

  41. What could be some other animals we’ve artificially selected? Holstein Texas longhorn Black Angus Ponies Draft Horses Thoroughbreds

  42. Artificial selection is how all of our crops and food animals have become big, resistant to the environment, delicious and nutritious!

  43. Many times in history people have endorsed the artificial selection of people to “improve” the human race. This is called “eugenics” and is essentially a justification for genocide or other human rights abuses.

  44. In the 1936 Olympics, held in Berlin, Germany, team USA sent Jessie Owens, an African American track and field athlete. He won 4 gold medals, humiliating the Nazi Germans, who were eager to use the Olympics to demonstrate their race’s “superiority.” Who’s the inferior race now?

  45. What are the 4 steps of natural selection? How does this picture show each of these steps?

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