Term 3 - 05 Evolution.pdf

EVOLUTION CHARLES DARWIN THEORY OF EVOLUTION This means that if an environment changes, the traits that enhance survival in that environment will also gradually change, or evolve. Natural selection was such a powerful idea in explaining...

EVOLUTION CHARLES DARWIN THEORY OF EVOLUTION This means that if an environment changes, the traits that enhance survival in that environment will also gradually change, or evolve. Natural selection was such a powerful idea in explaining the evolution of life that it became established as a scientific theory. THEORY OF EVOLUTION Darwin defined evolution as "descent with modification," the idea that species change over time, give rise to new species, and share a common ancestor. The mechanism that Darwin proposed for evolution is natural selection. THEORY OF EVOLUTION “It is not the strongest of the species that survives, nor the most intelligent, but the one most responsive to change.” - Charles Darwin, 1809 VOYAGE OF THE BEAGLE  VOYAGE OF THE BEAGLE Charles Darwin – born in England on February 12, 1809 (same birthday of Abraham Lincoln) He joined H.M.S. Beagle (name of the ship) in 1831. How old was he then?  VOYAGE OF THE BEAGLE Wherever the ship anchored, Darwin went ashore to COLLECT specimens. Whenever Darwin gets bored in his travel, he will read, write and draw in his notebooks. Charles Darwin’s curiosity and analytical nature helped his success in Science. He was able to explain the diversity of life on Earth.  VOYAGE OF THE BEAGLE Brazilian Forest – Darwin collected 68 different beetle species.  VOYAGE OF THE BEAGLE Charles Darwin discovered that not all places with the same habitat has same species  VOYAGE OF THE BEAGLE Darwin saw the differences among the giant land tortoises that inhabit the islands and learned from the islands’ governor that the tortoises’ shells varied in the predictable ways from one island to another The shape of the tortoises’ shells corresponds to different habitats EVOLUTIONARY THEORIES ORIGIN OF EVOLUTIONARY THOUGHTS James Hutton Thomas Malthus Jean-Baptiste Lamarck Charles Lyell Alfred Wallace  JAMES HUTTON “What more can we require? Nothing but time.” Hutton’s Theory of Geological Change Geological forces shaped the Earth (rain, heat, climate, etc.) Very slow formation of rocks, mountains, valleys, sea floor, etc. Earth’s age is more than a few thousand years old  THOMAS MALTHUS “The world’s population will multiply more rapidly than the available food supply.” Malthus’ Principle of Population Human population will grow faster There will be wars on food, space boundaries and resources  CHARLES LYELL “Each species may have had its origin in a single pair, or individual, where an individual was sufficient, and species may have been created in succession at such times and in such places as to enable them to multiply and endure for an appointed period, and occupy an appointed space on the globe.” Lyell’s Principle of Geology Explains past events in terms of processes that continue in the present Volcanoes release lava and gas, just as it did in the past Erosion continues to carve out canyons, just as it did in the past  CHARLES LYELL & CHARLES DARWIN Darwin and Lyell are very close to each other. Darwin trusts Lyell. Darwin even discussed his observations to Lyell. Darwin was amazed to find seashells on top of the mountains Darwin then thought that earthquakes could have lifted a stretch of rocky shoreline more than 3 meters above its previous position. Darwin understood that geological forces raised the sea floor rocks to a mountaintop.  JEAN-BAPTISTE LAMARCK “The form follows the function.” Lamarck’s Theory of Use and Disuse Organism’s organ when used always, will be enhanced. Organism’s organ when not used, will shrink or disappear. If the species don’t use it, they will lose it.  LAMARCK vs. DARWIN Darwin believe that 2 types of giraffes existed, but the short neck giraffes died off because they could not reach their food source. Only the long neck giraffes were able to survive and reproduce successfully.  LAMARCK vs. DARWIN Lamarck believe that the giraffes continued to attempt to reach for the tree leaves and in time their necks increased in length creating the giraffes that we see today.  ALFRED WALLACE “Why do some die and some live? The answer was clearly, that on the whole the best fitted live. From the effect of the disease the most healthy escaped; from the enemies, the strongest, swifest, or the most cunning, from famine, the best hunters or those with the best digestion; and so on. Then it suddenly flashed upon me that this self-acting process would necessarily improve the race, because in every generation the inferior would inevitably be killed off and the superior would remain-that is, the fittest would survive.”  WALLACE vs. DARWIN Darwin and Wallace develop similar theory Darwin began formulating his theory of natural selection in the late 1830s but he went on working quietly on it for twenty years. He wanted to amass a wealth of evidence before publicly presenting his idea. During those years he corresponded briefly with Wallace, who was exploring the wildlife of South America and Asia.  WALLACE vs. DARWIN Wallace supplied Darwin with birds for his studies and decided to seek Darwin's help in publishing his own ideas on evolution. He sent Darwin his theory in 1858, which, to Darwin's shock, nearly replicated Darwin's own.  WALLACE vs. DARWIN WHAT WALLACE DARWIN TIMELINE 1823-1913 1809-1882 NATIONALITY Welsh British (He claimed himself British) SOCIAL CLASS Born and died poor Born and died affluent EDUCATIONAL Hartford Grammar School Edinburg (Medicine, flopped) BACKGROUND (Completed 3rd Grade) Cambridge (BA in Theology) VOCATION Trapper and writer Naturalist and writer RELIGION No Religion Unitarian (abandoned later on)  WALLACE vs. DARWIN Both Darwin and Wallace are important contributors to biology and knowledge. In a finer scale, Wallace’s theory is more advanced than that of Darwin’s but Darwin had been more influential in making the theory acceptable to the intelligentsia.  WALLACE vs. DARWIN 1. If you’re Alfred Wallace, not that educated and not that rich, will you fight for your discovery? 2. What life lesson did you realize from Darwin-Wallace’s controversy? NEXT TOPIC: BIOTECHNOLOGY