0
S
Darwin’s Theory of
Evolution
Chapter 16
16.1 Darwin’s Voyage of
Discovery
S Charles Darwin
S Born Feb 12, 1809
S The first person to publish convincing evidence t...
Science Before Darwin
S In Darwin’s time, most people and scientists believed that
each species exists, unchanged as it ha...
S Jean Baptiste Lamarck, in 1809, proposed a
hypothesis of the inheritance of acquired
characteristics.
S This hypothesis ...
Darwin’s Epic Journey
S In 1831, at age 22, Darwin took a position as a naturalist on
a voyage of the HMS Beagle.
S On the...
Observations
S Three patterns of biological diversity:
1. Species vary globally
2. Species vary locally
3. Species vary ov...
Species Vary Globally
S Similar animals live in
separate, but similar
habitats.
Rheas – South America Ostrich - Africa
Species Vary Locally
S Different, yet related species occupied different habitats
in the same area.
Isabella Island Hood I...
Species Vary Over Time
S Fossils of extinct animals are similar to living species.
Putting it Together
S Darwin noticed that the finches on each of the Galápagos
islands had differently shaped beaks, and w...
16.3 Darwin Presents His
Case
S In 1858 Darwin published his ideas in the
book “On the Origin of Species.”
S This book out...
Struggle for Existence
S Though every organism has the potential to produce
many offspring, only a limited number of those...
Variation and Adaptation
S Individuals in a population vary in heritable characteristics
S Adaptations increase an organis...
Survival of the Fittest
S Fitness is how well an organism can survive and
reproduce in its environment.
S Individuals with...
Natural Selection
S These mechanisms allow for natural selection to occur.
S Each generation populations continue to chang...
16.4 Evidence of Evolution
The Age of the Earth and The Fossil Record
S Earth is 4.5 billion years old
S Fossils provide t...
S Although the fossil record is not, and will never, be
complete it presents strong evidence that evolution
has taken plac...
Comparing Anatomy and Embryology
S Homologous Structures
S Similarities in bone structure suggest that all vertebrates sha...
S Vestigial structures also provide evidence for evolution.
S Ex: hind limbs of whales and dolphins
Embryology
S At some time in their development all vertebrate embryos
have a tail, a notochord, and pharyngeal pouches.
S ...
Genetics and Molecular
Evidence
S Similarities in gene sequences can be linked to common
ancestry.
S Today we now know tha...
Examples of Evolution
Natural Selection at Work
S The key lesson scientists have learned about evolution by
natural select...
Notes ch16
Upcoming SlideShare
Loading in...5
×

Notes ch16

442

Published on

Published in: Technology, Education
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
442
On Slideshare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
5
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Transcript of "Notes ch16"

  1. 1. S Darwin’s Theory of Evolution Chapter 16
  2. 2. 16.1 Darwin’s Voyage of Discovery S Charles Darwin S Born Feb 12, 1809 S The first person to publish convincing evidence that species evolve, and propose a reasonable mechanism explaining how evolution occurs. S Modern organisms evolved over long periods of time through decent from common ancestors.
  3. 3. Science Before Darwin S In Darwin’s time, most people and scientists believed that each species exists, unchanged as it has for all time. S However, views were beginning to change dramatically S The Earth had changed along with all living things on Earth S With the discovery of more and more fossils scientists began to propose various mechanisms to explain how these species change over time.
  4. 4. S Jean Baptiste Lamarck, in 1809, proposed a hypothesis of the inheritance of acquired characteristics. S This hypothesis stated that by use or disuse of a body part could cause change in that feature within the lifetime of the organism. S These changes would then be passed on to offspring. S Lamarck’s hypothesis is now known to be incorrect.
  5. 5. Darwin’s Epic Journey S In 1831, at age 22, Darwin took a position as a naturalist on a voyage of the HMS Beagle. S On the Beagle’s 5-year journey it sailed around the world to map the coast of South America. S During the voyage Darwin found evidence that challenged the belief that species are unchanging.
  6. 6. Observations S Three patterns of biological diversity: 1. Species vary globally 2. Species vary locally 3. Species vary over time
  7. 7. Species Vary Globally S Similar animals live in separate, but similar habitats. Rheas – South America Ostrich - Africa
  8. 8. Species Vary Locally S Different, yet related species occupied different habitats in the same area. Isabella Island Hood Island
  9. 9. Species Vary Over Time S Fossils of extinct animals are similar to living species.
  10. 10. Putting it Together S Darwin noticed that the finches on each of the Galápagos islands had differently shaped beaks, and were similar to those in South America. S He spent years researching his ideas after he returned. S He began to wonder if the animals living on the different islands had come from a common ancestor.
  11. 11. 16.3 Darwin Presents His Case S In 1858 Darwin published his ideas in the book “On the Origin of Species.” S This book outlined Darwin’s ideas of evolution based on natural selection focusing on three principles: S The struggle for existence S Variation and Adaptation S Survival of the fittest
  12. 12. Struggle for Existence S Though every organism has the potential to produce many offspring, only a limited number of those survive and reproduce. 1 in 1000 survive to adulthood 50% survive past 1 year
  13. 13. Variation and Adaptation S Individuals in a population vary in heritable characteristics S Adaptations increase an organism’s ability to survive and reproduce. S Camouflage S Mimicry S Behaviors
  14. 14. Survival of the Fittest S Fitness is how well an organism can survive and reproduce in its environment. S Individuals with a high fitness are well suited for their environment and are more likely to survive and reproduce. S Individuals with low fitness are not as well suited to their environment therefore will either die or leave few offspring.
  15. 15. Natural Selection S These mechanisms allow for natural selection to occur. S Each generation populations continue to change as more individuals are born with favorable traits for the environment. S It is important to remember that if environmental conditions change faster than a species can adapt to the changes, the species may become extinct. S Example p. 462
  16. 16. 16.4 Evidence of Evolution The Age of the Earth and The Fossil Record S Earth is 4.5 billion years old S Fossils provide the most direct evidence that evolution takes place. S Fossils are preserved or mineralized remains or imprint of an organism that lived long ago. S Fossils provide an actual record of Earth’s past life forms. S Fossils are used to trace the evolution of modern species from extinct species.
  17. 17. S Although the fossil record is not, and will never, be complete it presents strong evidence that evolution has taken place. S Paleontologists analyze fossils by dating the rocks and minerals around it. S They can arrange the fossils from oldest to youngest, and in this, orderly patterns of evolution can be seen.
  18. 18. Comparing Anatomy and Embryology S Homologous Structures S Similarities in bone structure suggest that all vertebrates share a common ancestor.
  19. 19. S Vestigial structures also provide evidence for evolution. S Ex: hind limbs of whales and dolphins
  20. 20. Embryology S At some time in their development all vertebrate embryos have a tail, a notochord, and pharyngeal pouches. S Suggesting common ancestry
  21. 21. Genetics and Molecular Evidence S Similarities in gene sequences can be linked to common ancestry. S Today we now know that genes are responsible for inherited traits. S Traits become more common in a population because more individuals in the population carry the alleles for those forms. S Mutations and the recombination of alleles that occurs during sexual reproduction provide endless sources of new variations for natural selection to act upon. S Analyzing Data p.470
  22. 22. Examples of Evolution Natural Selection at Work S The key lesson scientists have learned about evolution by natural selection is that the environment dictated the direction and amount of change. S Ex: The polar bear’s white fur enables it to hunt successfully in its snowy environment. In a warmer environment, having white fur would no longer be an advantage. Examples of Natural Selection S Bacteria that cause disease evolve to have resistance to antibiotics. S Ex: TB, Staff
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×