1 / 17

Quiz- evidence of evolution and natural selection

Quiz- evidence of evolution and natural selection. Notes immediately following quiz. A. Living things produce more offspring than will survive. There is variation among the offspring. Offspring will compete for resources Those that have advantageous traits will survive and reproduce.

christen-burton
Download Presentation

Quiz- evidence of evolution and 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. Quiz- evidence of evolution and natural selection Notes immediately following quiz.

  2. A • Living things produce more offspring than will survive. • There is variation among the offspring. • Offspring will compete for resources • Those that have advantageous traits will survive and reproduce. • Those that do not have advantageous traits will die and take poor trait to their grave. D C E B A E B C D

  3. Compare the two animals listed below with the human cytochrome C protein segment. Which animal is most similar to humans? human: A A K J L C D Y T A A L M N organism #1: A A K T L C E Y T A A J M N organism #2: A A K J L C D Y J A A J M N • Would the organism you selected probably be a mammal or a reptile? Why? • Besides comparing biochemical evidence (amino acids), what other evidence do scientists have that evolution has occurred? (you had a journal on this last class!!) Fossils, biogeography, homologous structures, vestigial

  4. Look at the diagram at the right to answer the next few questions. • What is this diagram called? • Family tree • Cladogram • Phylogenetic tree • Both B and C • Which two animals are more closely related? • Gibbon & orangutan • Gibbon & human • Chimpanzee & bonobo • Bonobo & human • What led you to believe that the two animals you chose in #5 were more closely related? They are closer together on the cladogram and share the same most recent ancestor.

  5. Types of Natural Selection, Patterns & Rates of Evolution Biology 102Y SB5b. Explain the history of life in terms of biodiversity, ancestry, and the rates of evolution. SB5e. Recognize the role of evolution to biological resistance (pesticide and antibiotic resistance).

  6. Types of Natural Selection • Stabilizing- average phenotypes are favored • Plants- short plants can’t compete for sunlight so they die, tall plants can’t withstand winds so they die, this leaves medium height trees • Directional- population moves from one extreme to the other • Disruptive/Diversifying- extreme phenotypes are favored • Light and dark are favored so they survive, medium stick out and get eaten

  7. In peppered moths there are two major phenotypes- light color and dark color • Before the Industrial Revolution: • Light moths blend in, dark moths stick out, dark get eaten • Dark phenotype gets eaten so not very common so the dark allele is not frequent • After the Industrial Revolution: • Dark moths blend in, light moths stick out, light get eaten • Light phenotype gets eaten so not very common so the light allele becomes less frequent During the Industrial Revolution large amounts of air pollution killed the lichens on the tree, exposing the dark bark underneath. Before the Industrial Revolution light colored moths had a better chance of survival. After the Industrial Revolution dark colored moths had a better chance of survival. This change in the moth population over time is EVOLUTION of a POPULATION.

  8. Notice the peak of the blue line is over the light phenotype Notice the peak of the red line is over the dark phenotype This shows that the population evolved from light being more common before Industrial revolution to dark after. This type of natural selection is called… Change in Moth Phenotype from 1800’s-1900’s Moth Pop-ulation • Directional selection • Diversifying selection • Stabilizing selection Phenotypes of Moths

  9. Patterns of Evolution 1. Adaptive Radiation • Many species evolve from a common ancestor • Occurs as a result of geographic isolation- organisms are separated by a canyon or physical barrier and can’t breed together- creates new species • Also called divergent evolution • EX: one population that ended up being separated by Grand Canyon, developed into two new species- kaibab squirrel & abert squirrel • EX: Darwin’s finches

  10. Patterns of Evolution 2. Coevolution • Species evolve in close relationships with other species • Mutualism • Ex: flowers & their insect pollinators • Predator-prey • Ex: cheetahs & antelope • Ex: plant chemical defenses & insects

  11. Patterns of Evolution 3. Convergent evolution • Unrelated species evolve similar traits even though they live in different parts of the world. • Similarity in environment has led to evolution of similar traits. • EX: Madagascar aye-aye and New Guinea striped opossum both have elongated middle fingers. Live separately but have same structure

  12. Rates of EvolutionTwo Types: • Gradualism • Small, gradual steps • Traits remain unchanged for millions of years • Punctuated Equilibrium • Abrupt transitions • Seen in fossil record • Rapid spurts of genetic change caused divergence quickly

  13. What are some current trends in evolution? 1. Natural Selection • Bacteria are becoming resistant to antibiotics b/c of the misuse of antibiotics. Bacteria are building resistance. • Insects are also building resistance to pesticides due to overuse & improper use of the chemicals. • Industrial melanism- peppered moths changed due to pollution. • Generally, organisms that are more general in their needs survive. A species that requires a specific food source or habitat will be less able to change. 2. Artificial Selection • Genetically modified foods • Selective breeding in dogs & plants (crops) http://www.pbs.org/wgbh/evolution/educators/lessons/lesson6/act1.html

  14. 3. Genetic Drift • Genetic drift is a change in allele frequency due to a chance event. • EX: Small population of lizards: • 3 WW • 2 Ww • 5 ww • Earthquake kills 3 WW, frequency of “w” allele will increase and frequency of “W” will decrease • Two types of genetic drift…

  15. a. Bottleneck Effect • A change in a population’s allele frequencies due to a large reduction in population size • Population does not rebound as well • Reduced biodiversity may lead to inbreeding • Ex: Cheetahs killed due to disease or b/c they are pests- population so small they are inbreeding making species weaker so population is slow growing. • EX: volcanoes, natural disasters

  16. b. Founders Effect- • A change in a population’s allele frequencies due to colonization by a small number of individuals from a larger population. • Creates a “new” population elsewhere • Allele frequency in “new” population depends on what alleles migrated out. • EX: Small group of 200 Amish people migrated to US from Germany & Switzerland in 1700’s. Do not marry outside religion so interbreed. Many genetic disorders (dwarfism, metabolic disorders) common in their group.

More Related