1 / 15

The Revolutionary Ideas of Charles Darwin: Life, Voyage, and Natural Selection

Charles Darwin, born in 1809, lived in England and developed a passion for nature. Initially studying to be a physician, he dropped out and became a clergyman. His groundbreaking journey on the HMS Beagle (1831-1836) led him to observe diverse ecosystems, documenting his findings in "The Voyage of the Beagle." This laid the groundwork for his seminal work, "On the Origin of Species" (1859), where he articulated his theory of evolution through natural selection. His observations highlighted the struggle for existence and the significance of inherited traits in populations, revolutionizing biology.

haviva-black
Télécharger la présentation

The Revolutionary Ideas of Charles Darwin: Life, Voyage, 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. Darwin ExplainsNatural Selection Ch 22.2

  2. Darwin’s Life • 1809-1831 • Lived in England & fascinated with nature • Went to school to became a physician • Dropped out (disgusted by surgery) • Became a clergyman • 1831-1836 • Invited on the HMS Beagle • Hydrographic survey of South America

  3. Darwin Observes • Documented • Kept a Journal: The Voyage of the Beagle • Collected • Thousands of plants, animals, & fossils

  4. On the Origin of Species • 1836-1859 • Thinks about the voyage, animal/plant collection, fossils, geology… • Begins to describe the most revolutionary idea in biology • Receives a letter from colleague Alfred Wallace with same idea • They publish their idea together • Then Darwin finishes his book

  5. We change organisms • Artificial Selection: • humans modify species over many generations by selecting and breeding individuals with desired traits

  6. Cabbage Brussels sprouts Kale Cauliflower Broccoli Wild mustard Kohlrabi We change organisms

  7. Artificial Selection Today • http://www.hhmi.org/biointeractive/evolution/dog_breeding.html • https://www.youtube.com/watch?v=0jFGNQScRNY

  8. Observations from the voyage • Galapagos islands, while close to each other, contained: • Various ecosystems • Organisms similar to, but different from each other • Each had adaptations to fit the environment

  9. Observations • For any species, population sizes would increase exponentially if all individuals born reproduce successfully • Populations tend to be stable in size, except for seasonal fluctuations • Resources are limited

  10. Inference #1 • Production of more individuals than the environment can support leads to a struggle for existence among individuals of a population, with only a fraction of their offspring surviving

  11. Observations • Members of a population vary extensively in their characteristics • Much of this variation is heritable

  12. Inference #2 • Survival depends in part on inherited traits; individuals whose inherited traits give them a high probability of surviving and reproducing are likely to leave more offspring than other individuals

  13. Inference #3 • This unequal ability of individuals to survive and reproduce will lead to a gradual change in a population, with favorable characteristics accumulating over generations

  14. Summary of Evolution by Natural Selection • Organisms better suited to the environment are more likely to survive & reproduce than organisms less suited to the environment Mutation  Variation  Selection Individuals do NOT change; populations change

  15. Evolution by natural selection There is a grandeur in this view of life…

More Related