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Evolution. Change over time. Theory of Evolution. Idea supported by scientific evidence (but no concrete experiments) over a long period of time Change in a species due to mutation of the DNA code that occurs over a long time. Meiosis/Mitosis Connection.
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Evolution Change over time
Theory of Evolution Idea supported by scientific evidence (but no concrete experiments) over a long period of time Change in a species due to mutation of the DNA code that occurs over a long time
Meiosis/Mitosis Connection • Humans have 22 autosomal chromosomes and 1 sex chromosome (23 pairs of chromosomes total) in their sperm and egg cells. • It is on the 22 autosomal chromosomes that a mutation could occur
Who is Jean Lamarck? • 1744-1829 • One of the first to acknowledge unifying modification • He suggested that similar species came from a common ancestor • This was evident in fossil records
Lamarck’s Theory • “Acquired traits” • Use of structure results in evolution • Does not take into account DNA or sex cell mutations
Lamarck’s Rejection • His hypothesis was rejected, and easily disproved but, he was a forerunner of modern technology • He was the first to clearly state that types of organisms are a result of modifications over time • This idea was present more convincingly 50 years later
Charles Darwin • 1809-1882 • Known for two theories: • Decent with Modification • Modification by Natural Selection
Decent with Modification • All species have descended from one or a few “original “ types of life (common ancestor)
Natural Selection • “Survival of the Fit” • Limiting Factors Include: • Environment • Climate • Competition Resources • Fit Reproduce • Best adapted species will survive
Darwin’s key ideas: • A. REPRODUCTION: Organisms produce more offspring than can survive • B. VARIATION:Variety in traits exist • C. SURVIVAL OF THE FIT: Some traits allow survival & are passed on • D. Over time certain variations make up most of a population & they may be different from their ancestors
Darwin: Current theory Natural Selection “Survival of fit” Reproduction of the best adapted species Lamarck: “Acquired Traits” Theory Abandoned No knowledge of genetic traits or mutations in sex cells Theories of Evolution:
ACTIVITY • Using the concept map • Fill in as many words as you can at this moment… • Define each word: grab a Biology book to help you. • Take 10 minutes to do this
Evolution Evidence: 1. Fossils 2. Adaptations 3. Comparative anatomy 4. Comparative Biochemistry 5. Comparative embryology 6. Plate Tectonics
What we are going to do: • Over the next five days we will be looking at each one of these in depth. • This also means that we have an activity for the next five days • Some of these activities will be outside and you will be warned ahead of time!
1. Fossil Evidence: • Once living remains of organisms • Limited: • Type of material preserved (bone, shell, impressions, amber) • Incomplete record • Easily disrupted
Grand Canyon Lab • In groups of three you are to complete this lab activity. You have thirty minutes!
2. Adaptations:features suited to a particular environment that allow organisms to survive http://wc.pima.edu/Bfiero/tucsonecology/adaptations/adaptations_home.htm Inuit people, who live in the extreme cold of the Arctic, have short, stout bodies that conserve heat.
Masai people, who live in the arid lands of eastern Africa, have tall, lean bodies that disperse heat well.
Plant Adaptations: Venus Fly Trap • Captures Animals • Acquires Minerals • For Photo- synthesis Help!!!
Leaf Adaptations: Succulents • Thick • Store Water • Prevent Drying out
Leaf Adapatations: Pine Needles • Shed snow • Less water loss • Reduced surface area • Tolerate wind
Flower Adaptations: Fly pollination: • Hair along petals • Putrid smell Bee pollination: • Smooth petal • Sweet smell
Examples of Adaptations • Insecticides – Over the years many insects have become resistant to the type of insecticides we have been using. Why? • Species change – if a insect is susceptible to the insecticide they will die, the ones that are not survive and continue to reproduce.
Round-Up Ready Crops – crops have been genetically engineered to be resistant to round up, allowing the spray to be used and not controlled by what it touches • These plants can get out in the wild or crossbreed creating “super plants” that can no longer be controlled
Antibiotics – These are used to fight bacterial infections, but have become less successful in some cases. Why? • The bacteria that are susceptible die of, leaving on the strong ones to grow and multiple
What would you do? • Take the knowledge that you just learned, and explain in detail an adaptation you would want. Why would you want this adaptation? What draw backs could come about because of this adaptation? • At least 15 sentences
Wooly Worm Lab • Insects are a huge disturbance in agriculture. In this lab we will be looking at adaptations and natural selection in the dreaded wooly worm!
3. Comparative Anatomy:Structural similarities link related species
Analogous: Different ancestors “ana”=different Different underlying structures Same Function Similar Environments Homologous: Same ancestor “homo”=same Same underlying structures Different Functions Different Environments Comparative Anatomy Structures:
Analogous Structures • Different underlying structures (different ancestors) • Same function, similar environments Bird Wing Fly wing
Homologous Structures: Same underlying structures, different functions, different environments & common ancestor Bird Wing Porpoise Flipper
Comparative Anatomy Structures: • Vestigial Structures • Structures that are present, but not necessary • These structures show a change has occurred over time • Both whales and snakes have tiny leg like bones that are not visible or used showing that they evolved from animals that had legs
Cladogram Activity • How does a chart help teach us about anatomy?
4.Comparative Biochemistry • Similar DNA sequences= • Similar Gene segments of the DNA • Code for similar traits • In closely related species
Amino Acid Lab • To see how DNA sequences can be similar, but produce different animals…we will be looking at cladograms and DNA sequences together!
5. Comparative embryology: Similar embryo development in closely related species
Lets see how smart you are • Each group has gotten a baggie that contains a number pictures of 4 different organism’s embryos at different stages. • Your job is to correctly place the stages for each organism.
6. Plate Tectonics • Geological theory: • Continental masses were one land mass • Closely related species have common ancestors on now separated continents
Example: • Cattle: • Braham • Come from India • Hereford • Come from England • Both cattle are from a common ancestor and used for meat production, but they look different. This is because they evolved or changed due to their environment.