1. Gradual change in a species through adaptations over time.
Theory of Evolution
Gradual change in a species through adaptations over time.

2. Natural Selection (“Survival of the Fittest”)
Artificial Selection.
Darwin noted that farmers and animal breeders bred for certain variations in plants and animals to improve crops and livestock.
They would select for breeding only the largest hogs, the fastest horses, or the cows that produced the most milk.
Natural Selection (“Survival of the Fittest”)
Favorable variations over time that increase the organism’s ability to survive contribute to an organism's fitness in its environment. These changes are passed along to offspring
Natural selection also takes place without human control or direction.

3. Struggle for Existence
Members of each species compete regularly to obtain food, living space, and other necessities of life.
Fitness
Ability of an individual to survive and reproduce in its specific environment . Fitness is the result of adaptations over time
Adaptation
Any inherited characteristic that increases an organism's chance of survival

4. Evolution of Brains:

5. Charles Darwin “Survival of fittest” Fittest live to reproduce
Natural Selection:
“Survival of fittest”
Fittest live to reproduce
Competition for resources
Best adapted species survive

6. HMS Beagle Voyage 1835
Darwin left on a around the world voyage on the HMS Beagle in 1835.

7. HMS Beagle Voyage 1835
One of the places that Darwin visited was the Galapagos islands
Because of their remoteness Darwin studied the animals he found there
Darwin studied the changes in the beaks of Finches

8. Darwin’s key ideas: REPRODUCTION: VARIATION SURVIVAL OF THE FIT
Organisms produce more offspring than can survive
VARIATION
Variety in traits exist
SURVIVAL OF THE FIT
Some traits allow survival & are passed on
Over time certain variations make up most of a population & they may be different from their ancestors

9. Evolution Evidence: 1. Adaptations 2. Fossils 3. Comparative anatomy
4. Comparative embryology
5. Comparative Biochemistry
6. Plate Tectonics

10. Adaptations
Adaptations: features suited to a particular environment that allow organisms to survive
Inuit people, who live in the extreme cold of the Arctic, have short, stout bodies that conserve heat.

11. Adaptations
The Masai people, who live in the arid lands of eastern Africa, have tall, lean bodies that disperse heat well.

12. Camouflage Enables a species to blend with their surroundings to avoid detection by predators

13. Mimicry Enables one species to resemble another species; may provide protection from predators or other advantages
The smaller Viceroy butterfly that is tasty to birds mimics the larger Monarch which tastes bitter.
Leaf Insect on the right is almost indistinguishable from a actual leaf on the left

14. Bird Beak Adaptations:

15. Plant Adaptations: Venus Fly Trap Captures Animals Acquires Minerals
For Photosynthesis

16. Leaf Adaptations:
Succulents
Thick
Store Water
Prevent Drying out

17. Leaf Adaptations: Pine Needles Shed snow Less water loss
Reduced surface area
Tolerate wind

18. Flower Adaptations: Fly pollination: Hair along petals Putrid smell
Bee pollination:
Smooth petal
Sweet smell

19. Fossil Evidence: Once living remains of organisms Limited:
Type of material preserved (bone, shell, impressions, amber)
Incomplete record
Easily disrupted

20. Plant Fossil Evidence:

21. Comparative Anatomy: Structural similarities link related species

22. Comparative Anatomy Structures:
Homologous:
Same ancestor
“homo”=same
Same underlying structures
Different Functions
Different Environments
Analogous:
Different ancestors
“analogy”=like
Different underlying structures
Same Function
Similar Environments

23. Bird Wing Fly wing Analogous Structures
Different underlying structures (different ancestors)
Same function, similar environments
Bird Wing
Fly wing

24. Homologous Structures:
Same underlying structures, different functions, different environments & common ancestor

25. Vestigial Structures Structures in a present-day organism that no longer serve its natural purpose, but was probably useful to an ancestor, provides evidence for evolution
Mole Rat has skin covering it’s eyes making them a vestigial organ
Whale has pelvis bone

26. Comparative embryology:
Similar embryo development in closely related species
Chicken
Turtle
Rat

27. Comparative Biochemistry
Similar DNA sequences and similar gene segments of the DNA= Code for similar traits in closely related species

28. How do you define a Species? Same Species Must:
Show similar characteristics
Successfully
interbreed
Produce fertile offspring
Donkey + Horse =
Mule (infertile)

29. Movement of Tectonic Plates
In Darwin’s time, it was proposed that layers of rock, such as those that make up the distinct layers of sandstone, form very slowly.
The Earth was moved up by forces beneath Earth's surface creating changes to the sea floor and to form mountain ranges.
The resulting rocks, mountains, and valleys are then shaped by a variety of natural forces—including rain, wind, heat, and cold temperatures.
Most of these geological processes operate extremely slowly, often over millions of years. 29

30. Summary of Darwin's Theory
Individual organisms differ, and some of this variation is heritable.
Organisms produce more offspring than can survive, and many that do survive do not reproduce.
Because more organisms are produced than can survive, they compete for limited resources.
Each unique organism has different advantages and disadvantages in the struggle for existence. Individuals best suited to their environment survive and reproduce most successfully. These organisms pass their heritable traits to their offspring. Other individuals die or leave fewer offspring. This process of natural selection causes species to change over time.
Species alive today are descended with modification from ancestral species that lived in the distant past. 30

31. The Six Evidences of Evolution Foldable
Front
Back
The Six Evidences of Evolution
Fossils
Comparative Biochemistry
Embryology
Adaptations
Comparative Anatomy
Plate Tectonics
Picture
Definition:
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