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Blue edged slides taken from slide shows by: Kim Foglia  http://www.explorebiology.com Chapter 23- Evolution of populations Chapter 24-  Origin of species
2007-2008 Populations  evolve Individuals  are selected
REZNICK & ENGLER- (1980’s) Guppy experiments   Changes  in populations happened within 11 years  Age and size at sexual maturity change  depending on predators IMAGE FROM Campbell and Reece AP BIOLOGY
[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],IMAGE FROM Campbell and Reece AP BIOLOGY
[object Object],[object Object],IMAGE FROM Campbell and Reece AP BIOLOGY
Changes in populations 2005-2006 Insecticide resistance Pesticide molecule Insect cell membrane Target site Resistant target site Target site Decreased number of target sites
Fitness ,[object Object],[object Object],Body size & egg laying in water striders
Variation & natural selection  ,[object Object],[object Object],[object Object]
Where does Variation come from? ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Mean beak depth of parents  (mm) Medium ground finch 8 8 9 10 11 9 10 11 1977 1980 1982 1984 Dry year Dry year Dry year Wet year Beak depth Beak depth of offspring  (mm)
5 Agents of evolutionary change Mutation Gene Flow Genetic Drift Selection Non-random mating
1. Mutation & Variation  ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
2. Gene Flow ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Human evolution today ,[object Object],[object Object],Are we moving towards a blended world?
3. Non-random mating ,[object Object]
SEXUAL SELECTION ,[object Object],[object Object],[object Object],http://informalfotos.com/Fauna/Male%20Peacock%20displaying.JPG http://www.distinctivecruises.com/AfricanSafaris/MaleFemaleLion.jpg http://espanol.wunderground.com/data/wximagenew/i/icmoore/1013.jpg
KIN SELECTION ,[object Object],Bird that calls to warn others is in danger of being eaten, but does it anyway. Image from: http://www.kittens-lair.net/store/en/articles/sylvester4.jpg
4. Genetic drift ,[object Object],[object Object],[object Object],[object Object],[object Object],Warbler finch Tree finches Ground finches
Founder effect ,[object Object],[object Object],[object Object],[object Object],[object Object]
Bottleneck effect ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Cheetahs  ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Conservation issues ,[object Object],[object Object],[object Object],[object Object],Breeding programs must  consciously outcross Peregrine Falcon Golden Lion Tamarin
5. Natural selection ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
POLYGENIC traits are controlled by two or more genes. A bell shaped curve is  typical of polygenic traits Graph from BIOLOGY by Miller and Levine; Prentice Hall Publshing ©2006
[object Object],Graph from BIOLOGY by Miller and Levine; Prentice Hall Publshing©2006 Individuals at one end of the curve have higher  fitness than individuals in middle or at other end.  Graph shifts as some individuals fail to survive  at one end and succeed and reproduce at other Low mortality,  high fitness High mortality,  low fitness KEY Food becomes scarce.
Beak size varies in a population Birds with bigger beaks can feed  more easily on harder, thicker  shelled seeds. A food shortage causes small and  medium size seeds to run low. Birds with bigger beaks would be  selected for and increase in numbers  in population. EXAMPLE OF DIRECTIONAL SELECTION http://www.animalbehavior.org/ABS/Stars/ONI/Podos_-_finch_graphic.jpg
[object Object],Graph from BIOLOGY by Miller and Levine; Prentice Hall Publshing©2006 Individuals in center of the curve have higher  fitness than individuals at either end  Graph stays in same place but narrows as  more organisms in middle are produced.
Key Percentage of Population Brightness of Feather Color Selection against both extremes keep curve narrow and in same place. Section 16-2 Low mortality, high fitness High mortality, low fitness Stabilizing Selection Male birds use their plumage to attract mates. Male birds with less brilliant and showy plumage are less likely to attract a mate Male birds with showy plumage are more likely to attract a mate. Male birds with showier, brightly colored plumage also attract predators, and are less likely to live long enough to find a mate. The most fit is male bird in the middle-- showy, but not too showy .  STABILIZING SELECTION Graph from BIOLOGY by Miller and Levine; Prentice Hall Publshing©2006
Human babies born with low birth  weight are less likely to survive. Babies born too large have difficulty being born. Average size babies are selected for. EXAMPLE OF STABILIZING SELECTION
[object Object],Graph from BIOLOGY by Miller and Levine; Prentice Hall Publshing©2006 Individuals at extremes of the curve  have higher fitness than individuals in middle. Can cause graph to split into two.  Selection creates two DIFFERENT PHENOTYPES
A bird population lives in area  where climate change causes medium  size seeds become scarce while large  and small seeds are still plentiful. Birds with bigger or smaller beaks  would have greater fitness and the population may split into TWO  GROUPS. One that eats small  seeds and one that eats large seeds. EXAMPLE OF DISRUPTIVE SELECTION http://www.animalbehavior.org/ABS/Stars/ONI/Podos_-_finch_graphic.jpg
 
[object Object],[object Object],[object Object],[object Object],TWO DISTINCT SPECIES  Body and coloration are similar . . .  but their songs and other behaviors are different enough to prevent interbreeding
In the wild lions and tigers don’t interbreed but in zoos…  can get hybrids LIGER - Male lion X female tiger TIGON- Male tiger X female lion Largest cat in world . . . but male ligers are sterile http://www.readthesmiths.com/articles/Images/Humor/Liger.jpg http://laweekly.blogs.com/joshuah_bearman/images/tigon.jpg
 
 
 
 
 
Blue Footed Booby dance
 
 
 
 
 
 
Hybrid
 
 
 
(DIVERGENT EVOLUTION)
 
 
 
CURRENT DEBATE NOT over whether evolution happens  …  overwhelming evidence here! BUT . . .Does speciation happen gradually    OR rapidly in response to environmental change? GRADUALISM Change happens slowly “ Baby steps” over long Periods of time CHARLES DARWIN CHARLES LYELL
PUNCTUATED EQUILIBRIUM Niles Eldredge- Curator  American Museum of Natural History Rate of speciation is NOT CONSTANT Rapid change when 1 st  split from parent  population Unchanging for long periods  Stephen Jay Gould (1941-2002)  Paleontologist/evolutionary biologist TIME
 
 
 
 
 

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Ch. 23+24

  • 1. Blue edged slides taken from slide shows by: Kim Foglia http://www.explorebiology.com Chapter 23- Evolution of populations Chapter 24- Origin of species
  • 2. 2007-2008 Populations evolve Individuals are selected
  • 3. REZNICK & ENGLER- (1980’s) Guppy experiments Changes in populations happened within 11 years Age and size at sexual maturity change depending on predators IMAGE FROM Campbell and Reece AP BIOLOGY
  • 4.
  • 5.
  • 6. Changes in populations 2005-2006 Insecticide resistance Pesticide molecule Insect cell membrane Target site Resistant target site Target site Decreased number of target sites
  • 7.
  • 8.
  • 9.
  • 10. 5 Agents of evolutionary change Mutation Gene Flow Genetic Drift Selection Non-random mating
  • 11.
  • 12.
  • 13.
  • 14.
  • 15.
  • 16.
  • 17.
  • 18.
  • 19.
  • 20.
  • 21.
  • 22.
  • 23. POLYGENIC traits are controlled by two or more genes. A bell shaped curve is typical of polygenic traits Graph from BIOLOGY by Miller and Levine; Prentice Hall Publshing ©2006
  • 24.
  • 25. Beak size varies in a population Birds with bigger beaks can feed more easily on harder, thicker shelled seeds. A food shortage causes small and medium size seeds to run low. Birds with bigger beaks would be selected for and increase in numbers in population. EXAMPLE OF DIRECTIONAL SELECTION http://www.animalbehavior.org/ABS/Stars/ONI/Podos_-_finch_graphic.jpg
  • 26.
  • 27. Key Percentage of Population Brightness of Feather Color Selection against both extremes keep curve narrow and in same place. Section 16-2 Low mortality, high fitness High mortality, low fitness Stabilizing Selection Male birds use their plumage to attract mates. Male birds with less brilliant and showy plumage are less likely to attract a mate Male birds with showy plumage are more likely to attract a mate. Male birds with showier, brightly colored plumage also attract predators, and are less likely to live long enough to find a mate. The most fit is male bird in the middle-- showy, but not too showy . STABILIZING SELECTION Graph from BIOLOGY by Miller and Levine; Prentice Hall Publshing©2006
  • 28. Human babies born with low birth weight are less likely to survive. Babies born too large have difficulty being born. Average size babies are selected for. EXAMPLE OF STABILIZING SELECTION
  • 29.
  • 30. A bird population lives in area where climate change causes medium size seeds become scarce while large and small seeds are still plentiful. Birds with bigger or smaller beaks would have greater fitness and the population may split into TWO GROUPS. One that eats small seeds and one that eats large seeds. EXAMPLE OF DISRUPTIVE SELECTION http://www.animalbehavior.org/ABS/Stars/ONI/Podos_-_finch_graphic.jpg
  • 31.  
  • 32.
  • 33. In the wild lions and tigers don’t interbreed but in zoos… can get hybrids LIGER - Male lion X female tiger TIGON- Male tiger X female lion Largest cat in world . . . but male ligers are sterile http://www.readthesmiths.com/articles/Images/Humor/Liger.jpg http://laweekly.blogs.com/joshuah_bearman/images/tigon.jpg
  • 34.  
  • 35.  
  • 36.  
  • 37.  
  • 38.  
  • 40.  
  • 41.  
  • 42.  
  • 43.  
  • 44.  
  • 45.  
  • 47.  
  • 48.  
  • 49.  
  • 51.  
  • 52.  
  • 53.  
  • 54. CURRENT DEBATE NOT over whether evolution happens … overwhelming evidence here! BUT . . .Does speciation happen gradually OR rapidly in response to environmental change? GRADUALISM Change happens slowly “ Baby steps” over long Periods of time CHARLES DARWIN CHARLES LYELL
  • 55. PUNCTUATED EQUILIBRIUM Niles Eldredge- Curator American Museum of Natural History Rate of speciation is NOT CONSTANT Rapid change when 1 st split from parent population Unchanging for long periods Stephen Jay Gould (1941-2002) Paleontologist/evolutionary biologist TIME
  • 56.  
  • 57.  
  • 58.  
  • 59.  
  • 60.  

Hinweis der Redaktion

  1. Bent Grass growing on mine tailings; only individuals tolerant of toxic heavy metals will grow from the seeds blown in from nearby field
  2. Bent Grass growing on mine tailings; only individuals tolerant of toxic heavy metals will grow from the seeds blown in from nearby field
  3. Every individual has hundreds of mutations 1 in 100,000 bases copied 3 billion bases in human genome But most happen in introns, spacers, junk of various kind Not every mutation has a visible effect. Some effects on subtle. May just affect rate of expression of a gene.
  4. 1 family has a lot of children & grandchildren therefore has a greater impact on the genes in the population than other families Genghis Khan tracked through Y chromosome.
  5. Small founder group, less genetic diversity than Africans All white people around the world are descended from a small group of ancestors 100,000 years ago (Chinese are white people!)