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EVOLUTION…Part 1

Darwin. Natural Selection. EVOLUTION…Part 1. Chapter 16. Lamarck. Evidence. Charles Darwin. Born Feb. 12, 1809 in England 1831-1836 Served as a naturalist aboard the HMS Beagle 1835 The Beagle arrived in the Galapagos Islands (off the coast of South America)

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EVOLUTION…Part 1

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  1. Darwin Natural Selection EVOLUTION…Part 1 Chapter 16 Lamarck Evidence

  2. Charles Darwin • Born Feb. 12, 1809 in England • 1831-1836 Served as a naturalist aboard the HMS Beagle • 1835 The Beagle arrived in the Galapagos Islands (off the coast of South America) • 1859 Published Origin of Species • 1882 He died and was buried at Westminster Abbey near Isaac Newton

  3. Darwin’s Contribution to Science Developed a scientific theory of biological evolution that explains how modern organisms evolved over long periods of time through descent from common ancestors

  4. Darwin’s Observations #1- Different, but ecologically similar, animal species inhabited separated, but ecologically similar, habitats around the globe.

  5. Example of #1 • Rheas in South American grasslands are similar to ostriches in Africa. Both are similar to emus in Australia

  6. RHEA OSTRICH EMU

  7. Darwin’s Observations #2- Different, yet related, animal species often occupied different habitats within a local area.

  8. Example of #2 Giant Land Tortoises in the Galapagos Isabela Island (high peaks, rainy, vegetation close to the ground)- dome shaped shell and short neck Hood Island (flat, dry, sparse vegetation)- long neck and shell that is open around the neck and legs to allow stretching to reach food

  9. tortoises

  10. Darwin’s Observations #3- Noticed that some fossils of extinct animals were similar to living species

  11. Example of #3 Darwin unearthed fossils of the extinct glyptodont, a giant armored animal similar to an armadillo.

  12. Lamarck’s Ideas • 1809- hypothesized that organisms could change during their lifetimes by selectively using or not using various parts of their bodies.

  13. Lamarck’s Ideas • Also suggested that once an organism had changed, the acquired trait could be passed to offspring. Her babies will not be born with purple hair

  14. Lamarck was incorrect, but… • He was one of the first naturalists to suggest that species can change • Tried to explain the change scientifically using natural processes • Recognized a link between environment and body structures

  15. Artificial Selection vs. Natural Selection • Darwin knew all about how humans could use hybridization and inbreeding to get desirable traits in organisms (artificial selection) • Natural Selection involves the favorable traits being “chosen” by nature

  16. Darwin’s thoughts on Natural Selection explained a lot about evolution, but he couldn’t explain HOW traits change over time. The field of genetics explains this…MUTATIONS (they are not always bad).

  17. DARWIN AND HIS THEORY OF EVOLUTION Most organisms give birth to more offspring than can survive. OVERPRODUCTION Living things must struggle to exist. COMPETITION The individuals in a species are somewhat different from one another. VARIATION

  18. Organisms with traits best suited to the environment have a better chance of survival. ADAPTATION Those organisms best suited to their environment will pass their traits along to offspring. NATURAL SELECTION New species will develop. SPECIATION

  19. Now, who wants to play a game? I wanna play! Click on the guy to play

  20. What is evolution? Slow, gradual change over time Just in the last few million years, hundreds of species have become extinct- while hundreds of others have developed “Slow” means thousands to millions of years

  21. Evidence of Evolution • Fossil Evidence • Anatomical Structures • Embryological Development • Molecular Similarities

  22. FOSSILS (Dead Things) The remains of a plant or animal that lived long ago may be used to compare how the organism has changed over time or even evolutionary relationships.

  23. ANATOMICAL SIMILARITIES (Body Parts of Living or Dead Things) Structural similarities and differences can indicate evolutionary relationships.

  24. 3 Types of Anatomical Structures • Homologous- similar internal structure & development of embryos, but different form and function. • Whale flipper & human arm • Analogous- similar external form & function, but different internal structure. • Butterfly wing & bird wing

  25. Homologous Structures

  26. Insect & Bird are analogous structures Bat & Bird are Homologous structures

  27. The last type of anatomical evidence • Vestigial- structures that are remnants of structures that were functional in ancestral forms (reduced in size and serve little or no purpose). Whales have tiny structures that are vestigial pelvis and femur bones.

  28. Embryological Development(Living Things Before Birth) Comparing embryos at various stages of development may show similarities not present after birth. Fish Salamander Tortoise Chicken Rabbit Human

  29. MOLECULAR SIMILARITIES(Tiny Parts Inside Living or Dead Things) • DNA sequencing… comparing DNA or proteins of various species.

  30. This is the end of Ch. 16 notes • Review the vocab terms • Be sure you know about Darwin’s theories • Be able to explain how Lamarck’s and Darwin’s ideas are different • Be able to list and explain the different types of evidence for evolution…including the three types of anatomical similarities

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