Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million...
-
Upload
melvyn-anthony -
Category
Documents
-
view
215 -
download
0
Transcript of Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million...
![Page 1: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/1.jpg)
Chapter 32 Theories of Evolution
![Page 2: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/2.jpg)
Introduction• Biologists have classified more than 1.5 million
species of organisms for far.• Many scientists estimate that there may be 10
million species of organisms living on earth.***Review Classification• What does a Scientific name consist of?
1. Kingdom order2. Class species3. Phylum Genus4. Genus species
![Page 3: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/3.jpg)
Classification Review
• What is the correct way of writing the scientific name for a Lion?
1.panthera leo
2.Panthera leo
3.Panthera leo
4.panthera Leo
![Page 4: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/4.jpg)
Introduction cont.• As we know there are differences between
organisms of different species.• In addition, there are also differences among
organisms of the same species (variations).
![Page 5: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/5.jpg)
Why are there so many variations among organisms?
• Evolution is responsible for this great diversity!• Evolution: the process by which organisms
change over time.
![Page 6: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/6.jpg)
Evolution• Until the 19th century, most scientists believed that organisms existed as they had first appeared on earth.
• However, by the 1800’s geologists were finding and studying many fossils.
• What do you think these fossils showed?
• Scientists began wondering how and why living things may have changed?
![Page 7: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/7.jpg)
Evolution cont.During this time 2 biologists proposed a theory on evolution:
![Page 8: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/8.jpg)
Lamarck's Theory• Proposed his theories in 1809• 1st hypothesis:–Organisms develop traits, or characteristics by
the use or disuse of body parts.• Ex: If the body part is used, it becomes
larger and stronger. If the body part is not used, it becomes smaller and weaker.
![Page 9: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/9.jpg)
Lamarck's Theory cont.
• 2nd hypothesis:–Acquired characteristics, or the traits that
organisms develop during their lifetimes, are passed from parents to their offspring• Ex: Giraffe
• He didn’t have any observations or evidence to support his theory.
• Therefore most scientists did not support his theory.
![Page 10: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/10.jpg)
Lamarck's Theory cont.
![Page 11: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/11.jpg)
Investigations of Charles Darwin• British Naturalist born in 1809.• At the age of 22 Darwin voyaged on the HMS
Beagle.• HMS Beagle went on a mapping and collecting
expedition to South America and the South Pacific.
![Page 12: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/12.jpg)
What did Darwin observe during his 5 year voyage?
• How earthquakes and other geological processes change the land.
• He observed thousands of species of plants and animals
• Collected fossils• Notes on all his observations
![Page 13: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/13.jpg)
Darwin’s Finches
![Page 14: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/14.jpg)
Darwin’s Theory of Evolution• 20 years after his voyage, he published a book
called On the Origin of Species by Means of Natural Selection.
• What are Darwin’s main ideas about evolution?1.Overproduction2.Competition3.Variations4.Survival of the Fit
![Page 15: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/15.jpg)
Darwin’s Theory of Evolution cont.1. Overproduction: Each species produces many
more organisms than can survive and reproduce.
• Ex: Crabs, codfish, salmon, sea turtles
![Page 16: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/16.jpg)
Darwin’s Theory of Evolution cont.
2. Competition: due to overproduction of offspring, organisms must compete for limited resources (food, water, & a place to live)
![Page 17: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/17.jpg)
Darwin’s Theory of Evolution cont.3. Variation: differences among traits, occur
among members of the same species.
![Page 18: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/18.jpg)
Darwin’s Theory of Evolution cont.
4. Survival of the Fit: Organisms with traits that make them well adapted to their environment have a better chance to surviving and reproducing (natural selection).
![Page 19: Chapter 32 Theories of Evolution. Introduction Biologists have classified more than 1.5 million species of organisms for far. Many scientists estimate.](https://reader030.fdocuments.us/reader030/viewer/2022032722/56649f455503460f94c6706e/html5/thumbnails/19.jpg)
Darwin’s Theory of Evolution cont.
• Organisms that survive and reproduce pass on their traits to their offspring.
• As the process of natural selection continues through many generations, species change and become better adapted to their environment.
• As a result, evolution occurs by natural selection.