210 likes | 350 Views
Review. Drosphilia (fruit fly) eye color : Red eyes (R) and white eyes (r) Set up a cross between a pure bred red eyed fruit fly and a white eye-colored fruit fly. Describe the phenotypes of the offspring. What percent of the offspring will be: Heterozygous (show the genotype)
E N D
Review • Drosphilia (fruit fly) eye color: Red eyes (R) and white eyes (r) • Set up a cross between a pure bred red eyed fruit fly and a white eye-colored fruit fly. • Describe the phenotypes of the offspring. • What percent of the offspring will be: • Heterozygous (show the genotype) • Homozygous dominant (show the genotype) • Homozygous recessive (show the genotype) What is the main genetic difference between red eyed adn white eyed flies?
Objective 7: Evolution You should be able to: • Identify or state(level 1-2) • Define or Describe (3-4) • Explain or discuss (5-6) • The basics of evolution • The basics of natural selection • The evidence for evolution
Objective 7: Vocabulary • theory • evolution • natural selection • random • artificial selection • mutation • sexual selection • stratigraphy • fossil • radiometric dating • survival • reproduction • genes • chromosome • diversity • homologous • embryo
Evidence Discuss with your group and detemine what scientists would use to continue to test the theory evolution 1. 2. 3. 4.
Evidence – Fossil record • All are intermediates • Transition between quadruped and fish. • Tiktaalik - technically a fish with scales and gills — but with bones that would have allowed support in shallow water • inside fins are bones similar to human arm bones. • Ribs that would allow support over gravity 360MYA 385MYA scoop (What Has the Head of a Crocodile and the Gills of aFishMeyers 2006)
Stratigraphy • Layers of the Earth show the progression of life from simple to more complex • animals without backbones appear before vertebrates, amphibians appear after fish, etc. • Rock layers compared across the globe show complexity follows the same pattern • e.g., fossils of mammals are never found before the Triassic period.
Age of organic material & rocks • Radiometric dating - By measuring the amount of the parent atom and the daughter atom in a sample, the age of the organic remains or rock can be determined. • α & βdecay • SD = 1%
Oldest fossil • 3.4 billion year old fossilized cells of bacteria • Found in western Australia • The sandstone rock the fossils were found in were rocks were formed between two volcanic successions: radiometric dating • SD: few tens of millions of years (Discovered: The Oldest Fossils on Earth 2011)
Genetics • Comparative Anatomy: embryology & homologous strucutres • DNA & Gene sequences • Chromosomes
Evidence – Comparitive Anatomy • Comparing the skeletal and embryo structure • Shared ancestry or shared environment Activity
Evidence - Genes • HOX genes – set of genes that control how the body is put together • found in all animals • when the mouse HoxB6 gene is inserted in Drosophila, legs form in place of antennae. Line = DNA, each color = gene sequence 6 11 15 2
Evidence – genes • Pax6, gene located on chromosome 11 • involved in the development of eyes and other sensory organs. • Same gene in mice, fruit flies, humans, and squid • In one study, mouse Pax6 put into fruit fly = eye formation in fruit flies = evidence of shared ancestry • Aniridia – the absence of an iris caused by a mutation in the PAX6 gene. • 2/3 of the cases are inherited and dominant trait. • 1/3 of the cases result from a random mutation • occurs in 1 in 50,000 to 100,000 newborns worldwide (PX 1999)
Silver fox experiment • Starting in 1959 Russian geneticist Dmitry Belyaevchoose for one trait in the silver fox: tamability • Changes in Phenotypes seen in under 10 generations: alterations in coat color, floppy ears, and curved tails. (Adams 2008) • Also more serotonin in blood (Scott) http://ngm.nationalgeographic.com/2011/03/taming-wild-animals/ratliff-text
Guppies • Endler saw that males in some locations had many more spots, on average, than the males in other populations. • Endler’s hypothesis: color change was due to the presence of predators • Endlercollected guppies from 18 locations in 11 different streams. • Fish moved into artificial ponds for about 6 months—long enough for several generations of fish to grow up, reproduce, and die. http://evolution.berkeley.edu/evosite/evo101/IVB1bInthelab.shtml
Endler divided his guppy population among 10 greenhouse ponds. • four ponds he added a single cichlid. • four ponds he added half a dozen Rivulus. • two ponds he left without predators as controls. • After five months and 14 months Endlersampled male guppies and counted their spots. • The male guppies in the pond without any predators and in the pond with Rivulus had an average of 13 spots. • The male guppies in the pond with the cichlids had an average number of 9 spots http://www.pbs.org/wgbh/evolution/sex/guppy/low_bandwidth.html
Videos and other resources on Evolution http://www.youtube.com/watch?v=ewtw_nZUIDQ&feature=related (evidence) http://www.youtube.com/watch?v=xkwRTIKXaxg&feature=related (how evol. works) http://www.youtube.com/watch?v=x5NG8SYQSzE&feature=related (humans) http://www.youtube.com/watch?v=B7zo2zY1Zqg (song) http://www.youtube.com/watch?v=D1_-mQS_FZ0 (meiosis) http://www.astro.umd.edu/~miller/teaching/astr380f09/slides08.pdf (excellent ppt)
Resources • Adams, J. "Genetics of Dog Breeding." Nature.com. Nature Publishing Group, 2008. Web. 27 Mar. 2013. <http://www.nature.com/scitable/topicpage/genetics-of-dog-breeding-434>. • "Artificial Selection in the Lab." Evolution 101: Microevolution. University of California, Berkley, n.d. Web. 08 Apr. 2014. <http://evolution.berkeley.edu/evosite/evo101/IVB1bInthelab.shtml>. • Fossil Evidence." Understanding Evolution. Web. 31 Jan. 2012. <http://evolution.berkeley.edu/evolibrary/article/lines_02>. • "Discovered: The Oldest Fossils on Earth." News RSS. University of Oxford, 22 Aug. 2011. Web. 08 Apr. 2014. <http://www.ox.ac.uk/media/news_stories/2011/110822.html>. • Jensen, Judy Elgin. NSTA Tool Kit for Teaching Evolution. Arlington, VA: NSTA, 2008. Print.
Resources • Jensen, Judy Elgin. "NSTA Tool Kit for Teaching Evolution." NSTA, 2008. Web. 31 Jan. 2012. <http://NSTA-Tool-Teaching-Evolution-PB228X/dp/1933531460>. • Meyers, P. Z. "Tiktaalik Makes Another Gap." National Geographic, 5 Apr. 2006. Web. 27 Mar. 2013. <http://scienceblogs.com/pharyngula/2006/04/05/tiktaalik-makes-another-gap/>. • Owen, James. "Fossil Fish With "Limbs" Is Missing Link, Study Says." Daily Nature and Science News and Headlines | National Geographic News. 5 Apr. 2006. Web. 31 Jan. 2012. <http://news.nationalgeographic.com/news/2006/04/0405_060405_fish.html>. • "PAX6." Genetics Home Reference. U.S. National Library of Medicine, 7 Apr. 2014. Web. 08 Apr. 2014. <http://ghr.nlm.nih.gov/gene/PAX6>.
Resources • Px, Xu, and Zhang X. "Regulation of Pax6 Expression Is Conserved between Mice and Flies." National Center for Biotechnology Information. U.S. National Library of Medicine, Jan. 1999. Web. 08 Apr. 2014. <http://www.ncbi.nlm.nih.gov/pubmed/9847251>. • Gilbert, Scott F. "Evolution and Domestication: Selection on Developmental Genes?" Chapter 23. Developmental Biology 9e Online:, n.d. Web. 08 Apr. 2014. <http://9e.devbio.com/article.php?id=223>. • Trut, Lyudmila. "Early Canid Domestication: The Farm-Fox Experiment." American Scientist, Mar.-Apr. 1999. Web. 07 Apr. 2014. <http://www.americanscientist.org/issues/page2/early-canid-domestication-the-farm-fox-experiment>. • "What Has the Head of a Crocodile and the Gills of a Fish?" Understanding Evolution. University of Berkley, June 2010. Web. 27 Mar. 2013. <http://evolution.berkeley.edu/evolibrary/news/060501_tiktaalik>.
Resources • "What Has the Head of a Crocodile and the Gills of a Fish?" Understanding Evolution. University of Berkley, June 2010. Web. 27 Mar. 2013. <http://evolution.berkeley.edu/evolibrary/news/060501_tiktaalik>. • "What Is a Gene Mutation and How Do Mutations Occur? - Genetics Home Reference." Genetics Home Reference - Your Guide to Understanding Genetic Conditions. Web. 29 Jan. 2012. <http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/genemutation>. • Wolchover, Natalie. "How Many Genetic Mutations Do I Have? | LifesLittleMysteries.com." Home | LifesLittleMysteries.com. 16 June 2011. Web. 29 Jan. 2012. <http://www.lifeslittlemysteries.com/1536-mutants-average-human-60-genetic-mutations.html>.