The document compares the theories of evolution of Lamarck and Darwin. Lamarck believed that organisms evolve because they need to and can pass on acquired traits to offspring. His theories were later disproven. Darwin proposed the theory of natural selection, where individuals with traits most suited to the environment survive and pass on those traits, leading to the evolution of species over time as favorable adaptations accumulate and unfavorable ones disappear.

1. THEORIES OF
EVOLUTION
LAMARCK VERSUS DARWIN

2. LAMARCK’S THEORIES OF EVOLUTION
JEAN BAPTISTE LAMARCK
• DEVELOPED ONE OF THE FIRST
THEORIES ON HOW SPECIES
CHANGED.
• CONCLUDED THAT ORGANISMS OF
HIGHER COMPLEXITY HAD EVOLVED
FROM PRE-EXISTING, LESS COMPLEX
ORGANISMS.

3. 1. THEORY OF
NEED
2. THEORY OF
USE AND
DISUSE
3. THEORY OF
ACQUIRED
CHARACTERISTICS

4. LAMARCK’S THEORIES OF EVOLUTION
1. THEORY OF
NEED
ORGANISMS CHANGE BECAUSE
THEY NEED TO.
FOR AN ORGANISM TO EVOLVE A
STRUCTURE, IT MUST NEED THE
STRUCTURE.

5. LAMARCK’S THEORIES OF EVOLUTION

6. LAMARCK’S THEORIES OF EVOLUTION
2. THEORY OF USE
AND DISUSE
• IF YOU DON’T USE IT, YOU LOSE
IT!
• ORGANISMS DEVELOP
SPECIALIZED CHARACTERISTICS
BY THE USE OF DISUSE OF
ORGANS.

7. LAMARCK’S THEORIES OF EVOLUTION
3. THEORY OF ACQUIRED
CHARACTERISTICS
• IF A PARENT ACQUIRES A BODY
STRUCTURE DURING ITS
LIFETIME, IT COULD PASS ON
THAT CHARACTERISTIC
STRUCTURE TO ITS OFFSPRING.

8. DISPROVING LAMARCK’S
THEORIES
1. PETALS OF FLOWERS
2. CORSETS
3. FREQUENT EXERCISE
4. TAILS OF MICE

9. DARWIN’S THEORY OF NATURAL SELECTION
CHARLES DARWIN
• PROPOSED AN ENTIRELY DIFFERENT
MECHANISM TO ACCOUNT FOR THE
EVOLUTION OF SPECIES.
• HIS THEORY OF EVOLUTION BY
NATURAL SELECTION BECAME THE
FOUNDATION OF MODERN
EVOLUTIONARY STUDIES.

12. DARWIN’S FINCHES
CHARLES DARWIN WAS ABLE
TO SEE 14 VARIETIES OF
FINCHES, WHICH VARIED IN
SIZE AND SHAPE OF BEAKS
FROM ISLAND TO ISLAND.
TOOK HIM 20 YEARS TO
ORGANIZE HIS DATA.
DARWIN’S THEORY OF NATURAL SELECTION

14. NATURAL
SELECTION
INDIVIDUALS WITHIN A
POPULATION WITH THE
MOST FAVORABLE TRAITS
FOR AN ENVIRONMENT
SURVIVE AND PASS ON
THOSE TRAITS.

15. NATURAL SELECTION: 6 MAIN
POINTS
1. SPECIES
OVERPRODUCTION
ORGANISMS TEND TO OVER
REPRODUCE.

16. NATURAL SELECTION: 6 MAIN
POINTS
2. COMPETITION
• THERE IS A STRUGGLE OF
EXISTENCE AND THE
SURVIVAL OF THE FITTEST.
• LIVING SPACE AND FOOD
ARE LIMITED.

17. NATURAL SELECTION: 6 MAIN
POINTS
3. VARIATION
• NO TWO INDIVIDUALS ARE
THE SAME.
• PLANTS AND ANIMALS OF
THE SAME SPECIES DIFFER
IN SIZE, STRENGTH AND
ADAPTIVE STRUCTURES.

18. NATURAL SELECTION: 6 MAIN
POINTS
4. ADAPTATION
• IT IS A PROCESS OF
BECOMING BETTER SUITED
TO THE ENVIRONMENT.
• IT IMPROVES AN
ORGANISM’S CHANCE OF
SURVIVAL.

19. NATURAL SELECTION: 6 MAIN
POINTS
5. NATURAL SELECTION
• ENVIRONMENT SELECT
ORGANISMS THAT SURVIVE
TO BE THE PARENTS OF
SUCCEEDING
GENERATIONS.

20. NATURAL SELECTION: 6 MAIN
POINTS
6. SPECIATION
• FAVORABLE ADAPTATION
GRADUALLY ACCUMULATE
IN THE SPECIES AND
UNFAVORABLE ONES
DISAPPEAR.

21. LAMARCK’S THEORY

22. DARWIN’S THEORY