CHAPTER 29 EVOLUTION Evolution: Isn't Evolution Just a Theory?
EVOLUTION KEY TERMS • Evolution • Fossil • Founder effect • Gradualism • Natural selection • Punctuated equilibrium • Speciation • Embryology • Primate • Vestigial Structure • Catastrophism • Mutation • Uniformitarianism • Adaptation • Genetic drift
Type I What do you know about evolution? What do you want to know? Do you believe in evolution? Why or why not? Write response in 7 lines
Type I What does evolution mean to you in everyday language? What does evolution mean to you in the language of science?
Early Ideas on Evolution _______________ _______________ _______________ _______________ Carolus Linnaeus, 1735 Georges Buffon, 1749 Erasmus Darwin, 1749 Jean-Baptiste Lamarck, 1809 2nd to classify organisms based on their _________ Proposed that species shared ________________ Proposed that more complex life forms arose from _______ complex life forms Proposed that changes in an environment caused changes in ________________ traits ancestors less organisms
Theories of Geologic Change sets the stage for the Theory of Evolution CATASTROPHISM GRADUALISM UNIFORMITARIANISM
CATASTROPHISM Georges Cuvier Theory proposed by _______________________. States that ______________________________ such as ___________ and _______________________________ have shaped ________________ and caused species to become ___________________ in the process. Natural disasters floods volcanic eruptions landforms extinct GRADUALISM James Hutton Theory proposed by ______________________. States that the changes in landfoms resulted from ___________________ that had occurred over a long period of time. slow changes UNIFORMITARIANISM Theory proposed by ______________________. States that the changes in geologic processes that shape the Earth are uniform through time. __________________________________________________________________________________ Charles Lyell The changes have happened in the past and are ONGOING!
Type I Making Predictions/Making Connections: What does the concepts of ‘Geological Change’ have to do with the concept of ‘Evolution’?
Review • List four events that could cause change according to CATASTROPHISM • _____________________ _____________________ • _____________________ _____________________ • What is the difference between CATASTROPHISM AND GRADULISM? • GRADULAISM AND UNIFORMITARIANISM are more closely related, describe • this relationship and how they differ.
A cat, quick enough to snatch a bird successfully today, might not be speedy enough to catch the next generation of birds, because only the swiftest of yesterday’s birds remain to provide offspring. Type I: write a 5 line response to the statement above about how it relates to evolution
ADAPTATIONS Traits that make a living thing able to survive in its surroundings. TYPES OF FEET TYPES OF BEAKS WEBBED FISH INSECTS CLAWED HOOVED PADDED NUTS FISH
Type I Understanding Write down three organisms and describe how they are adapted to their environment.
OTHER ADAPTATIONS COLORATION BODY FAT AND THICK FUR SPECIAL CHARACTERISTICS ADAPTATION ACTIVITY
Why doesn't the bird have teeth? Because it doesn't eat meat and has no need for them. _______________________ _______________________
WHICH MOTH WOULD BE MOST RECOGNIZABLE BY ITS PREDATOR? What happens to the moth that is not selected by the predator? 1. It survives 2. It passes on his traits _______________________ _______________
WHICH MOTH WOULD BE MOST RECOGNIZABLE BY ITS PREDATOR? What happens to the moth that is not selected by the predator? 1. It survives 2. It passes on its traits _______________ _______________________
NATURAL SELECTION Who determined which moth was better adapted to its surroundings? OWL _____________________________ Principles of NS Natural Selection- process in which something in nature does the selecting of what will survive and what will not survive. ____________________ - ______________________________________ ___________________________________________________________ ___________________________________________________________
WHAT THINGS IN NATURE CAN SELECT WHO LIVES? PREDATORS WEATHER CONDITIONS RESOURCE SHORTAGES DISEASE ____________________________ _________________________________________ _______________________________________________ ____________________________
Preying Mantis: Camouflaged to hide from its prey. Would you see it?
Walking Stick: Camouflaged to hide from its predators.
Thorn Bug: Camouflaged to hide from its predators.
ADAPTATIONS IN REVIEW Adaptations = traits Traits = genes Adaptations = genes ______________________________ ______________________________ ______________________________
Type II Define Natural Selection. List four different kinds of ‘Natural Selectors’ and give an example of each: 1. 2. 3. 4.
“You do not carry your genes around as a way of reproducing yourself; your genes carry you around as a way of reproducing themselves”
MUTATIONS • A CHANGE IN THE DNA CODE • ARE NATURAL EVENTS • CAN BE A SOURCE FOR NEW TRAITS • THESE NEW TRAITS CAN BE ADAPTATIONS BECAUSE THEY MIGHT HELP THE ORGANISM SURVIVE IN ITS ENVIRONMENT __________________________________ _______________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________
ARE ALL MUTATIONS BAD? -NO- BROWN COAT TO WHITE COAT BROWN COAT TO WHITE COAT HELPFUL __________________ HARMFUL The brown rabbit is more easily seen by predators. It will most likely not survive and reproduce. __________________ The white deer is more easily seen by predators. It will most likely not survive and reproduce.
What determines what a GOOD gene is or a BAD gene??? Environment (nature) An albino gene is BAD in a forest environment. The animal will die. An albino gene is GOOD in a snowy environment. The animal will flourish!!
Genetic variation in a population increases the chance that some individuals will survive. • Genetic variation leads to phenotypic variation. • Phenotypic variation is necessary for natural selection. • Genetic variation is stored in a population’s gene pool. • made up of all alleles in a population • allele combinations form when organisms have offspring
measures how common allele is in population • can be calculated for each allele in gene pool • Allele frequencies measure genetic variation.
Genetic variation comes from several sources. • Mutation is a random change in the DNA of a gene • Recombination forms new combinations of alleles • can form new allele • can be passed on to offspring if in reproductive cells • usually occurs during meiosis • parents’ alleles arranged in new ways in gametes
bald eagle migration Gene flow is the movement of alleles between populations. • Gene flow occurs when individuals join new populations and reproduce. • Gene flow keeps neighboring populations similar. • Low gene flow increases the chance that two populations will evolve into different species.
Genetic drift is a change in allele frequencies due to chance. • Genetic drift causes a loss of genetic diversity. • It is most common in small populations. • A population bottleneck can lead to genetic drift. • It occurs when an eventdrastically reducespopulation size. • The bottleneck effect isgenetic drift that occursafter a bottleneck event.
It occurs when a few individuals start a new population. • The founder effect is genetic drift that occurs after start of new population. • The founding of a small population can lead to genetic drift.
Genetic drift has negative effects on a population. • less likely to have some individuals that can adapt • harmful alleles can become more common due to chance Mechanisms of evolution Founder effect
Type III Define Genetic Variation (1 pt) List two different factors that lend itself to genetic variation.(2pts) 1. 2. List and describe two ways that genetic frequencies change in a population over time. (2 pts)
Type I How do you suppose elephants are from both Asia and Africa?
SPECIES FORMATION Species – A group of living things that can breed with others of the same species and form ‘FERTILE’ offspring. Speciation – evolution of 2 or more species from one ancestral species Punctuated equilibrium – theory that speciation occurs suddenly and rapidly followed by long periods of little change Fertile – being able to reproduce by forming egg or sperm cells
SPECIES FORMATION New species are formed by: • Animals within the same species are separated by a barrier, (water, mountains, etc). • They live apart for thousands of years with different living conditions. 2. Natural selection takes place within the two separate regions. 3. Individuals with the desirable traits for their specific environment survive and reproduce. 4. Over time the two groups can become different species as they develop different adaptations. 5 Fingers of Evolution _________ __________________________ _________ _____________________ _______________ _____________________ _________
Type I Name at least 3 things that have to happen in order for a new species for originate. 1. 2. 3.
Galapagos Islands • Seed Eaters • Plant Eaters • Insect Eaters • Cactus Eaters Your Text Here
CHARLES DARWIN Naturalist • English __________________ who wrote the __________________________ • Developed the ___________________________ • Stated that evolution is a _______________ in the ______________ ______________ of a group of organisms over time. Origin of the Species Theory of Evolution change hereditary features Controversy