2. Evolution What we know, so far…. Many different species alive today
All life shares common characteristics
The Earth is very old
Life is very old
Life has changed over time
The changes have been little changes over long periods of time
Evolution
But how does this work?

4. Arctic Fossils
Arctic Fossils

5. Arctic Fossils

6. Charles Darwin Father of Evolution Proposed a way how evolution works
How did creatures change over time?
by natural selection
Collected a lot of evidence to support his ideas
British naturalist
What did Darwin say?
What evidence supports Evolution by Natural Selection?
What impact did Evolution have on biology?

7. Voyage of the HMS Beagle
Invited to travel around the world
(5 year journey!!)
records many observations of nature and took notes & drew pictures in hundreds of notebooks
After graduation Darwin was recommended to be the conversation companion to Captain Robert FitzRoy, preparing the survey ship Beagle for a voyage around the world.
FitzRoy chose Darwin because of his education, his similar social class, and similar age as the captain.
Darwin noted that the plants and animals of South America were very distinct from those of Europe

8. Voyage of the HMS Beagle
Stopped in Galapagos Islands
500 miles off coast of Ecuador
The origin of the fauna of the Galapagos, 900 km west of the South American coast, especially puzzled Darwin.
On further study after his voyage, Darwin noted that while most of the animal species on the Galapagos lived nowhere else, they resembled species living on the South American mainland.
It seemed that the islands had been colonized by plants and animals from the mainland that had then diversified on the different islands

9. The origin of the fauna (animals) of the Galapagos, 900 km west of the South American coast, especially puzzled Darwin.
Darwin noted that while most of the animal species on the Galapagos lived nowhere else, they resembled species living on the South American mainland.
It seemed that the islands had been colonized by plants and animals from the mainland that had then diversified on the different islands

10. Darwin found… many unique species
Many of Darwin’s observations made him wonder… Why?
Darwin asked:
Why were these creatures found only on the Galapagos Islands?

11. Darwin found… clues in the fossils
present day Armadillos
Darwin found:
Evidence that creatures have changed over time
Darwin asked:
Why should extinct armadillo like organisms & modern armadillos be found on same continent?
ancient Armadillo like organism

12. Darwin found: Different shells on tortoises on different islands
Darwin asked:
Is there a relationship between the environment & what an animal looks like?

13. The finches clinched it for Darwin

14. Darwin’s Finches Darwin’s conclusions: 1. Variations in beaks
differences in beaks in the original flock
adaptations to foods available on islands
2. Natural selection for most fit (survival of the fittest)
over many generations, the beak adaptations allowed survivors to create the population diversity
3. Offspring inherit successful traits
Best adaptations allow offspring to out-compete others and survive to reproduce
4. This creates new species over time

15. Earlier ideas on Evolution
Jean Baptiste LaMarck
evolution by acquired traits
Organisms change their adaptations through use
Give those new adaptations to their offspring
example
in reaching higher leaves giraffes stretch their necks & give the acquired longer neck to offspring
not accepted as valid

16. Darwin’s view of Evolution
giraffes that already have long necks survive better
leave more offspring who inherit their long necks
variation
selection & survival
reproduction & inheritance of more fit traits 

17. What is Natural Selection?
Competition for resources
for food, water, mates, habitat & nesting sites, escape predators
BIOLOGICAL Fitness
having the adaptations to out-compete others for resources
reproduce to produce VIABLE offspring
Survival of the Fittest = organisms with the “best” traits/adaptations survive to reproduce and pass on traits
YOU CANNOT PASS ON YOUR GENES IF YOU ARE DEAD!

18. Descent With Modification
Darwin concluded:
Each species has descended, with changes, from other species over time.
Darwin called this…
Descent With Modification
Today, we call it…
Evolution
(change in a population over time)

19. Evolution explains Unity & Diversity
Evolution shows how organisms can be similar and how organisms can be different

20. Artificial Selection
Humans choosing which organisms reproduce & survive = “Evolution by human selection”
Ex. Designer breeds of dogs

21. Artificial Selection
Two chickens at 8 weeks old: one artificially selected & one naturally selected
Artificially inseminated to produce chicken with more meat mass

22. Data that supports Evolution (population change over time)
Fossil record
Comparative embryology
Artificial selection works
Molecular record
DNA comparisons
Amino acid sequence comparisons
Anatomical record
Homologous structures
Analogous structures
Vestigial organs

23. Speciation - The process of creating new species.
Capable of reproducing with each other
Changes in gene pool produce changes in species
Changes result in speciation = evolution of new species

24. What selective pressures promote speciation?
Geographic isolation: physical separation, like rivers, mountains, or bodies of water.
The Kaibab squirrel (left image) diverged/evolved from the Albert’s squirrel (right image)
Separated by Colorado river in the Grand Canyon

25. What selective pressures promote speciation?
Temporal isolation: different breeding seasons
Both are spiny reptiles, but the upper (bunch grass spiny) breeds only in the spring. The Yarrow’s spiny only breeds in the fall.

26. Darwin’s finches
Speciation from geographic isolation and founder’s effect leading to breeding incompatibility

27. Convergent Evolution (creating analogous structures)
The evolution of useful traits happen independently of each other in different species. They DO NOT come from a common ancestor.

28. Camouflage and Mimicry
Structural adaptations

29. 1. Camouflage
Any color, pattern, shape or behavior that enables an animal to blend in with its surroundings
Short Videos:
Cuttlefish, master of camouflage
Walking stick

30. Tasseled Scorpion Fish

31. Frog

32. Owl

33. Scorpion Fish

34. Leaf-tailed Gecko

35. Crocodile

36. Caterpillar

37. Wolf

38. Mimicry
Appearing or behaving like another species which protects one or both
Coral Snake (venomous)
King Snake (nonvenomous)

39. This tropical lo moth, once a caterpillar with an honest signal now sports eyespots on its hind wings, which it displays when threatened.

40. The red "eyes" and pointed "stinger" are both fake.
Munching on a plant stem in Costa Rica's Monteverde Cloud Forest Reserve, this Xylophanes caterpillar has such tiny eyes that you would need a hand lens to see them.
The red "eyes" and pointed "stinger" are both fake.
Actual eyes

42. Viceroy butterfly (non poisonous) Monarch butterfly (poisonous)

43. In the lowland rain forest of the Peruvian Amazon, a "bird dropping" on a leaf turns out to be a caterpillar.

44. Wasp attempts to mate with hammer orchid which mimics female wasp (click)
This is an example of Mimicry and Co-Evolution
(the orchid and the wasp have evolved over time, together)