Download CHAPTER 6 ADAPTATIONS OVER TIME

CHAPTER 6 ADAPTATIONS OVER TIME
SECTION 1 IDEAS ABOUT EVOLUTION
EARLY MODELS OF EVOLUTION
 LAMARCK – SAID CHARACTERISTICS DEVELOPED BY INDIVIDUALS
OVER TIME WERE PASSED ON TO OFFSPRING – WRONG
 DARWIN – THEORY OF EVOLUTION BY NATURAL SELECTION –
ORGANISMS WITH TRAITS MORE SUITED TO THEIR ENVIRONMENT
ARE MORE LIKELY TO SURVIVE AND REPRODUCE – TRAITS ARE
PASSED ON
 POPULATIONS COMPETE FOR LIVING SPACE, FOOD AND OTHER
RESOURCES
PRINCIPLES OF NATURAL SELECTION
 ORGANISMS PRODUCE MORE OFFSPRING THAN CAN SURVIVE
 VARIATIONS OCCUR AMONG INDIVIDUALS OF A SPECIES
 SOME VARIATIONS ARE PASSED ON
 SOME VARIATIONS ARE HELPFUL FOR SURVIVAL AND
REPRODUCTION, AND ARE PASSED ON TO OFFSPRING
 OVER TIME, INDIVIDUALS WITH HELPFUL VARIATIONS MAKE A
LARGER POPULATION
VARIATIONS AND ADAPTATIONS
 VARIATIONS RESULT FROM MUTATIONS IN AN ORGANISMS GENES
 VARIATIONS CAN BE SMALL OR LARGE
 IF INDIVIDUALS W/ VARIATION CONTINUE TO SURVIVE AND
REPRODUCE A NEW SPECIES CAN EVOLVE
 ADAPTATIONS MAKE AN ORGANISM BETTER SUITED TO ITS
ENVIRONMENT
CHANGES IN SOURCES OF GENES
 GENETIC MAKEUP OF A SPECIES MIGHT CHANGE ITS APPEARANCE
GEOGRAPHIC ISOLATION
 INDIVIDUALS MAY BE SEPARATED FROM REST OF POPULATION AND
DEVELOP VARIATIONS
 CAN ALSO DEVELOP GENE MUTATIONS TO ADD VARIATIONS
SPEED OF EVOLUTION
 GRADUALISM – SLOW PROCESS OF EVOLUTION OVER LONG PERIOD
OF TIME
 PUNCTUATED EQUILIBRIUM – SUDDEN CHANGE IN POPULATION
DUE TO GENE MUTATIONS
PUNCTUATED EQUILIBRIUM TODAY
 BACTERIA BECOME RESISTANT TO ANTIBIOTICS QUICKLY AND ARE
ABLE TO SURVIVE - PNEUMONIA