1 / 28

Evolution by Natural Selection

Evolution by Natural Selection. Chapters 14-18. History. Charles Darwin , DOB 1809, On the Origin of Species by Means of Natural Selection , HMS Beagle – 1831-36 Greeks – life arose in water and more complex followed simpler ones Later Aristole said life was fixed (ps. he’s wrong)

wilona
Download Presentation

Evolution by Natural Selection

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Evolution by Natural Selection Chapters 14-18

  2. History • Charles Darwin, DOB 1809, On the Origin of Species by Means of Natural Selection, HMS Beagle – 1831-36 • Greeks – life arose in water and more complex followed simpler ones • Later Aristole said life was fixed (ps. he’s wrong) • Judeo-Christians agreed • Mid 1700s fossils of “strange animals” were found • Jean Baptiste de Lamark suggested acquired traits were inherited. Used = got better, Unused = go away. (ps…he’s half wrong)

  3. History • Dad wanted him to get into medicine, then he went to become a priest – Met John Henslow – took a cruise. • While on the boat he read Principles of Geology by Charles Lyell. • “mountains rise cm by cm” • The way the rain falls today is the same way it fell 1billion years ago. • UNIFORMITARIANISM • Learned about Thomas Malthus • Human population should be huge but - War, Disease, Famine limits the population

  4. History • So Darwin is on a cruise… • Finds sea animal fossils thousands of feet above sea level • Finds FINCHES similar to the mainland but 600miles out to sea GALAPAGOS ISLANDS • Realizes that kids look like parents After his trip, he thinks about this stuff for a little while…like 20years • Alfred Wallace sends him a paper that is the same idea that he has come to and Darwin quickly publishes. The conclusion…?

  5. Descent with Modification • Organisms that exist today are modified versions of older organisms. • The environment chooses the organisms that are best fit to reproduce (natural selection). • The better fit the organism the more babies it will produce, the more of those genes are in the gene pool. • Traits that help an organism survive better and make more babies are ADAPTATIONS

  6. Evidence – 6 pieces • 1. Fossils • 2. Biogeography • 3.Homologous/Analogous Structures • 4. Embryology • 5. Molecular Biology (macromolecules) • 6. Vestigial Structures

  7. 1. Fossils • Traces of long dead organisms • Sediments • Law of superposition: • Which happened first, tree falling or it snowed? • Fossil Record: The theoretical ‘stack’ of all fossils, in order

  8. Fossil Lab • Align and fix the locations in place. Answer the following questions: • Which locality is the oldest? How do you know? • Which locality is the youngest? Where might you find this in the Earth’s crust? • Approximately how many years are represented in your localities? Are there any huge gaps? • Why aren’t all the fossils in the same place? • Is there a pattern to the complexity of the fossils? • How do fossils form? What does this tell you about the organisms that we find as fossils (or what about the one’s we don’t find)? • Do you think fossils are strong evidence for evolution? Why or why not.

  9. 2. Biogeography • Organisms that are relatively close (NJ and PA) are more alike than organisms that are far apart. • More pouched animals in Austrailia • Galapagos Finches

  10. 3.Homologous/Analogous Structures • ‘Homo’ means … so these are parts in different species of animals that are the same. • Analogous – same function but different structure

  11. Figure 13.11

  12. 4. Embryology • In the early stages of development, many species are similar.

  13. 5. Molecular Biology (macromolecules) • Large compounds in organisms are sometimes similar • Protein • Hemoglobin • Starch

  14. 6. Vestigial Structures • Remnants of structures that served a purpose in ancestral organisms but have little or no function now. • Appendix • Wisdom teeth • Tails

  15. Natural Selection • The organism that is best fit to the environment makes the most babies and passes on the most genes. • DEPENDS COMPLETELY ON GENETIC MAKEUP • Individual variation (longer legs, sharper teeth, darker color) • If its not the environment choosing but people we call it ARTIFICIAL SELECTION • Cows • Sheep • Bacteria • Chemicals - ddt

  16. Gene pool – all of the genes in a population • Population – a group of mating individuals in the same place at the same time. • We can identify if evolution is taking place based on the Hardy-Weinburg Equation • p2 + 2pq + q2 = 1 • Certain events can cause evolution to occur more quickly • Bottle neck event • Founder event • Gene flow – immigration, emmigration • Mutation

  17. Figure 13.22

  18. Figure 13.23

  19. Sometimes evolution occurs in a specific pattern • Directional Selection • Disruptive Selection • Stabilizing Selection

  20. Taxonomy • Names and groups organisms according to their characteristics and evolutionary history • Carolus Linnaeus (1707-1778) • Binomial Nomenclature • Species identifier • Varieties- peach and nectarine • Subspecies – different area • A species is defined as organisms that can reproduce and form fertile offspring.

  21. SystematicsvsCladistics • Systematics – classification in the context of evolution • Fossil record • Morphology • Phylogenic tree • Cladistics – derived characters • Cladograms • Weird relationships

  22. Domains – • Eukarya • Bacteria • Archaea • Kingdom • Phylum • Class • Order • Family • Genus • Species

  23. Kingdoms (Modern Bio p348-9) • Animalia • Plantea • Fungi • Protista • Eubacteria • Acheabacteria

  24. Story of Life • What is living? • Order • Regulation/Homeostasis • Growth and Development • Energy Utilization • Respond to the environment • Reproduction • Evolution • Spontaneous Generation- living things from nonliving things (frogs came from mud) • Francesco REDI 1650: Disproved spontaneous generation with meat, flies, jars • Lazzaro SPALLANZANI 1750: Disproved spontaneous generation with boiled broth, new story-vital force • Louis PASTEUR 1850: Disproved both spontaneous generation and vital force with s-shaped flask

  25. Story of Life • Miller and Urey Experiment on how life began • Water + ammonia + • CO2 + Nitrogen = • Organic compounds! • PROKARYOTES • Endosymbiosis- • Lynn Margulis 1950 • One or a few microorgs • Living together became • our organelles = • EUKARYOTES

  26. Prokaryotes • Found everywhere • Kingdoms Bacteria, Archaea • Mostly unicellular and very small • No nucleus or organelles • Shapes: Bacilli, cocci, spirochete • Photoauto/heterotroph- Chemoauto/hetero- how they eat • Pathogen

  27. Eukaryotes • Lynn Margulis- endosymbiont theory • Smaller prokary climbed inside larger prokay and was happy together • Kingdoms Protista, Plant, Fungi, Animals • Larger cells, have nucleus and organelles • VERY diverse

More Related