In its most basic terms, the theory of evolution states that species CHANGE over time.

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2 In its most basic terms, the theory of evolution states that species CHANGE over time. Lamark Use Disuse Hypothesis or Passing on of Acquired Characteristics

3 Summarize how Lamark believes the giraffe got its long neck. At first all giraffes had short necks. In order to reach the leaves in the trees the giraffe stretched its neck. All of this stretching actually lengthened the giraffes neck. This was passed onto the offspring and the next generation had longer necks. This kept happening and that is how we have the long neck giraffe today. What is wrong with the inheritance of acquired traits hypothesis? Parents pass DNA (genes) to their kids, not characteristics they obtain during their lifetime.

4 NATURAL SELECTION - Organisms with useful traits survive, reproduce, and pass those traits to their offspring.

5 Summarize how Darwin believes the giraffe got its long neck. Giraffes had different length necks to begin with. Those with the longer necks had an advantage and reached the leaves in the trees. These giraffes survived and reproduced and passed the gene for a long neck onto their offspring. Natural selection - Organisms with useful traits survive, reproduce, and pass those traits to their offspring. Survival of the fittest - measure of an individual s ability to survive and reproduce more offspring that can in turn survive and to reproduce. Descent with modification - we are changed forms of our ancestors.

6 Gradualism - gradual change over time leads to species formation Punctuated equilibrium evolution occurs in spurts in which there are periods of rapid change in a species followed by periods of little or no change (usually do to major environmental changes)

7 *** GENES mutate INDIVIDUALS are selected POPULATIONS evolve***

8 small genetic changes in the gene pool of a population GENE POOL all the alleles in a population (look at the # of B s vs. the # of b s)

9 DIRECTIONAL SELECTION it pays to be different individuals with traits at one end are more common than midrange forms Ex: peppered moths STABILIZING SELECTION it pays to be average eliminates individuals on both ends of the range and favors midrange individuals Ex: birth weights DISRUPTIVE OR DIVERSIFYING SELECTION both ends of the range are favored and those in the middle are reduced. Ex: finch beaks

10 Before the Industrial Revolution the trunks of certain trees were a light color. The lighter peppered moths had an advantage over the darker moths. The lighter moths were more likely to survive and reproduce so there were more of them in the population. However, with the Industrial Revolution came pollution. The trees turned dark. Now the darker moths had the advantage. Adaptations are dependent upon the environment.

11 MACROEVOLUTION changes in a species so a new species is formed GEOGRAPHICAL ISOLATION can lead to the formation of New Species Sometimes organisms of the same species become physically separated. The evolution of separate species is largely due to genetic drift (chance). After a long period of time even if the two groups were to meet back up the organisms may refuse to mate. At this point they would be considered separate species. When one species becomes 2 separate species this is called SPECIATION

12 Genetic drift - random changes in alleles of a gene pool due to chance. Affects smaller populations more.

13 COEVOLUTION changes in genetic composition of one species in response to change in another Ex: flowers & pollinators ADAPTIVE RADIATION - the changing of organisms to fit new environments.

14 DIVERGENT EVOLUTION - accumulation of differences between groups which can lead to the formation of new species CONVERGENT EVOLUTION - organisms that are not closely related evolve similar traits due to living in similar environments. These are ANALOGOUS structures..

15 1. Fossil Evidence Fossils show patterns of development LAW OF SUPERPOSITION fossils found deeper down in the strata (rock layers) are older than those found closer to the top.

16 2. Anatomical structures VESTIGIAL STRUCTURES structures that are present in an organism but reduced in size or have less important function (Ex: wings in flightless birds, hind limbs in whales) HOMOLOGOUS STRUCTURES structures that share a common ancestry (similar structure but different functions) Ex: human arm, bat wing, whales flipper

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19 3. Molecular Evidence for Evolution If species change over time then genes have also changed (DNA fingerprinting) COMMON ANCESTOR a species from which 2 or more species have diverged DNA PROTEINS Scientists look at and. The more similar the DNA or protein sequence, between 2 different organisms, the more recently they shared a common ancestor.

20 CLADOGRAMS PHYLOGENETIC TREES & show how organisms are related through evolution

21 In the cladogram below, the greater the evolutionary distance from humans, the greater the number of amino acid differences in the hemoglobin protein (polypeptide).

22 EMBRYONIC development shows common ancestry similarities in early development show similar genes are at work

23 A review of experiments: Abiogenesis vs. biogenisis ABIOGENESIS - life from non-living Ex: food left out (non-life) had maggots (life) crawling in it a few days later. BIOGENESIS life from living How did the maggots really end up on the food? FLIES LAYING EGGS ON THE FOOD AND THE EGGS HATCH.

24 Miller & Urey conducted an experiment. Describe the purpose of this experiment. show how organic compounds were formed from inorganic compounds. They found a.a. (amino acids) which are organic. Important b/c amino acids make proteins which are needed for life.

25 Explain the Endosymbiosis Theory. Eukaryotic cells were formed when smaller prokaryotes moved inside larger prokaryotes and they formed a relationship. Shows evolution of more complex cells.

26 Evolution of Life - the order of their suspected appearance on Earth)he first life forms: Were they? Circle one of the pairs of terms below prokaryotic autotrophic or or eukaryotic heterotrophic Aerobic (used oxygen) or Anaerobic (didn t use oxygen) What chemical process occurred that allowed there to be aerobic organisms? Explanation SIMPLEST CELL NO NUCLEUS HETEROTROPHS JUST EAT FOOD, THEY DON T ACTUALLY MAKE IT THERE WASN T ANY OXYGEN ON EARLY EARTH PHOTOSYNTHESIS BECAUSE IT RELEASES OXYGEN Based on the info from the table list the order of organisms as they appeared on Earth. ANAEROBIC, HETEROTROPHIC PROKARYOTES ANAEROBIC, AUTOTROPHIC PROKARYOTES AEROBIC PROKARYOTES EUKARYOTES

27 Picture Terms Define Cells that don t need oxygen anaerobic prokaryotes (heterotrophs) Cells without a nucleus Obtain energy by eating photosynthetic prokaryotes (autotrophs) Use light to make food Cells without a nucleus Make own food

28 Picture Terms Define aerobic prokaryotes Cells that need oxygen Cells without a nucleus unicellular eukaryotes One cell Cells with a nucleus multicellular eukaryotes Many cells Cells with a nucleus

29 1 Earth is formed with toxic gases, water vapor, and no oxygen 8 Eukaryotic cells (more complex cells with a nucleus) form through endosymbiosis 2 Earth s surface cools and water vapor forms oceans as it rains 3 Simple organic molecules such as amino acids and carbohydrates form from the thunderstorms 4 Protocells (non-living groups of molecules) form and contain RNA 6 Photosynthetic prokaryotes form adding oxygen to the atmosphere 7 Ozone (O 3 ) layer forms from atmospheric oxygen to protect Earth 9 Multicellular eukaryotes form 5 Prokaryotic cells form. Prokaryotes are simple cells that include bacteria.

30 NON-LIVING VERY SMALL CANNOT REPRODUCE ON OWN CAUSE DISEAESE DNA &/OR RNA LIVING BIT BIGGER REPRODUCE ON OWN

31 PASSIVE IMMUNITY short-term immunity when antibodies produced for a pathogen injected into the body or a mother gives a baby short term immunity until the infant can make its own antibodies Ex: being injected w/ antibodies that attack a rabies virus after being bitten Receiving vaccines before going to another country ACTIVE IMMUNITY - body makes own antibodies in response to an antigen

32 How do viruses infect cells???

33 ANTIBIOTICS block the growth or reproduction of bacteria (can t be used to fight viruses) Taken after an infection has started Ex: Take antibiotics for strep throat.

34 Antibiotics used only when needed and as directed usually overwhelm the bacteria. Too much antibiotic use selects for more resistant mutants. When patients cut short the full course of drugs, the resistant strains have a chance to multiply and spread.

35 VACCINES solutions containing weakened or killed pathogens (a pathogen is anything that causes disease) Taken prior to an infection to build antibodies against the pathogen Sometimes antibiotics were prescribed for viral infections. Viruses cannot be killed by antibiotics. There are ANTIVIRAL medications that treat viral infections by preventing the virus from developing.

36 ANTIGEN substance not recognized by the body that causes an immune response Antibody proteins that recognize and bind to antigens

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