1 / 42

EVOLUTION

EVOLUTION. EVOLUTION. The process of change through time. Evidences of Evolution Fossils-the remains of a once living organism Types of fossilization: Petrification Imprint Tar/Ice/Amber. FOSSILS. Fossils always form in sedimentary rock with the older organisms in the deeper layers.

mlancaster
Télécharger la présentation

EVOLUTION

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

  2. EVOLUTION • The process of change through time. • Evidences of Evolution • Fossils-the remains of a once living organism • Types of fossilization: • Petrification • Imprint • Tar/Ice/Amber

  3. FOSSILS • Fossils always form in sedimentary rock with the older organisms in the deeper layers.

  4. FOSSIL LAYERS

  5. PETRIFIED FOSSIL

  6. PETRIFIED WOOD

  7. TAR

  8. AMBER

  9. IMPRINT

  10. COMPARATIVE STUDIES • Evidence for evolution is also found by comparing: • Embryology • Biochemistry • Cytology • Anatomy

  11. COMPARATIVE EMBRYOLOGY

  12. COMPARATIVE EMBRYOLOGY • Animals go through similar stages of embryological development. • This may show that they are related and may share common ancestry

  13. COMPARATIVE BIOCHEMISTRY • Organisms have similar chemicals, which may show common ancestry. • Ex. • Hormones are similar in many species. • Everything contains DNA. • Similar protein structure and construction. • Use ATP • ….

  14. COMPARATIVE CYTOLOGY • The study of cells is CYTOLOGY. • All living things are made of cells, therefore, they may share a common ancestor.

  15. COMPARATIVE ANATOMY • Comparing the structures of different animals to find similarities. • Homologous Structures • Analogous Structures • Vestigial Structures

  16. HOMOLOGOUS STRUCTURES • Structures having a similar origin, but are adapted for different purposes. • Ex. Human arm and whale flipper • Same structure-Different function

  17. HOMOLOGOUS STRUCTURES

  18. ANALOGOUS STRUCTURES • Structures are different but have the same basic function. • Ex. Bee wing and Bird wing • Different structure-Same function

  19. VESTIGIAL STRUCTURES • Structures that presently have no known function, but may once have been needed. • Ex. Tonsils, appendix, whale, snake

  20. THEORIES OF EVOLUTION • Jean-Baptiste Lamarck (early 1800’s) • Theory of use and disuse • He said that characteristics which are acquired are inherited. • Ex. Giraffes & Human Muscles

  21. THEORIES OF EVOLUTION • August Weismann (late 1800’s) • Disproved Lamarck’s theory • He said that acquired characteristics are NOT inherited. • Studied mice

  22. THEORIES OF EVOLUTION • Hugo de Vries (late 1800’s) • One of the first geneticists • Developed mutation theory • Said mutations are a result of genes segregating, then recombining

  23. THEORIES OF EVOLUTION • Charles Darwin • “Father of Evolution” • Observed variation in species on the Galapagos Islands • Famous for his study of finches, among others.

  24. DARWIN’S THEORIES • Natural Selection • Organisms with favorable adaptations tend to survive and reproduce. • The 4 principles of Natural Selection: • 1. Overproduction-populations overproduce • 2. Competition-struggle for existence • 3. Variation-leads to new generations that are better adapted to environment • 4. Survival of the Fittest - the ones best adapted, survive.

  25. VARIATION • A bell curve shows variation within a population.

  26. VARIATION OF HEIGHT

  27. GEOGRAPHIC ISOLATION • Species that are separated from one another by natural barriers (mountains, ocean, desert) can cause new species to develop. • Ex. Emu, Ostrich, Rhea

  28. GEOGRAPHIC ISOLATION

  29. SPECIATION • Speciation • Over time, new species will develop due to their isolation. • Ex. Emu and Ostrich cannot interbreed

  30. ADAPTATIONS • An adaptation is a characteristic of an organism that helps it to function in it’s environment.

  31. ADAPTIVE RADIATION • The process by which a single species evolves into several different forms that live in different ways. • Causes diversity amongst the group of organisms.

  32. ADAPTIVE RADIATION

  33. GRADUALISM • Slow steady change over time (gradually)

  34. PUNCTUATED EQUILIBRIUM • Stable population makes a sudden and rapid change into something new.

  35. Punctuated equilibrium vs. gradualism

  36. ORIGIN OF LIFE • In the beginning… • ______________, which happened about _____________ years ago. • Then… • Molten earth cooled, forming a ___________. • Then… • Volcanoes erupted, spewing gases, forming the ____________.

  37. ORIGIN OF LIFE • The first gases in the primitive environment were: • NH4- Methane • CO2-Carbon Dioxide • NH3-Ammonia • H2S-Hydrogen Sulfide • These gases combined to form primordial soup

  38. ORIGIN OF LIFE • Early Earth was being bombarded by lightning and comets. • Lightning caused molecules in the primordial soup to reassemble into CHON. • Therefore, an organic molecule is born!

  39. ORIGIN OF LIFE • Simple organic molecules began to combine to form more complex molecules. • Ex. Simple proteins, carbohydrates, lipids and nucleic acids. • This occurred around 3 billion years ago.

  40. ORIGIN OF LIFE • Simple archaebacteria are formed about 2.5 billion years ago. • Archaebacteria evolved and adapted to the environment, forming simple monera, which then evolved into____________, which then evolved into____________.

  41. Miller and Urey Experiment • In the 1950’s, the scientists conducted an experiment to re create the formation of life.

  42. Experiment

More Related