1. Chapter 16
Primate Evolution

2. What is a primate ?

3. A primate is…
Humans Apes Monkeys Lemurs
Group of Mammals characterized by having nails on their hands and feet, a short snout, and a large brain.

4. What are some characteristics of primates?

5. characteristics of primates..
Flexible hands and feet
High level of dexterity ( This allows them to be able to grasp onto objects and move them around in their hands)
Well developed eyesight
Long mobile arms
Large brains (with this comes reasoning)

6. Why is an opposable first digit important?
* Opposable digits are what gives primates the ability to grasp objects and move them in their hands.
The hands and feet of all primates have…
5 digits
Flat nails
Sensitive areas on the end their digits
The first digit of the hand or feet are opposable.
Thumb or Toe
Set apart from other digits
Can cross palm and touch other side

7. How do forward looking eyes benefit primates?
Primates rely more on their vision then any other sense
They have from facing eyes
This creates a overlapping field of vision (binocular vision)
Forward facing eyes allows for better
Depth perception - Judgment of object placement and movement.
*Along with these changes came smaller snouts, Flattened faces (binocular vision) , and unspecialized teeth.
Diurnal
Active during the day
Color vision
Nocturnal
Active at night
Black and white vision

8. How do primates move? Primates rely on their hind limbs for movement
On the ground all primates except for humans walk on all four limbs
Some primates live in trees
Along with their flexible limbs (shoulders) they are able to move from branch to branch.

9. What are some characteristics of a primate brain?
Primates have large brains with large areas devoted to..
vision / few to smell
Memory
Arm to leg movement
Because of their brain size they are able to..
Solve problems
Engage in social behavior
Communicate through complex ways (facial expressions)
What is the reproductive rate of primates?
Female primates have a long pregnancies
Give birth to one offspring at a time
Infant is very dependent on mother for years ( Social skills )

10. Classified into two subgroups
Primate groups
Most primates are Arboreal (ar BOHR ee uhl) or tree-dwelling
Live in tropical and subtropical rain forest
Classified into two subgroups
Strepsirrhines
HAPLORHINES
“Wet nosed” primates
Earliest and most basic primates
Lemurs (most members)
“Dry nosed” primates
Human like primates
Tarsier ( unique primate)

11. Strepsirrhines Strepsirrhines group Lemurs Aye-ayes Lorises Galagos
Rely mostly on smell for hunting and social interactions
Have large eyes and ears
Live in tropical Africa and Asia ( Madagascar and islands)
Scientist believe that these animals evolved in isolation when the island of Madagascar drifted from the content of Africa.
Strepsirrhines group
Lemurs
Aye-ayes
Lorises
Galagos
Active period
Large-diurnal
Small-nocturnal
Nocturnal
Mostly nocturnal
Range
Madagascar
Africa and southeast Asia
Africa
Features
Vertical leaper
Uses tail for balance
Herbivores and omnivores
Tap bark, listen, fish on grubs with long third finger.
Small, slow climbers; solitude
Lack tail
Some have toxic

12. Haplorhines Tarsiers Monkeys Apes Live in Borneo and the Philippines
Nocturnal
Large eyes
Lives in trees
*can turn its head 180 degrees
Gibbons
Orangutans
Gorillas
Chimpanzees
humans
Tarsiers

13. Anthropoids Old world monkeys New world monkeys
larger than Strepsirrhines
larger brains for their body size
Diurnal- color vision
Complex social interactions
Anthropoids
New world monkeys
Old world monkeys
Africa
Asia
Europe
The Americas

14. What traits do new world monkeys share?
Live in the tropical forests of Mexico, Central America, and South America
Include
Marmosets
Tamerins
*No nails or opposable digits
*Some squirrels and spider monkeys have opposable digits
Diurnal
Live in social bands
Have prehensile tails (work as a fifth limb)
Can grasp trees and support entire weight.

15. What features distinguish old world monkeys?
Live in a wide variety of habitats throughout Asia and Africa
Two subgroups
Macaques and baboons
Colobus and proboscus
Diurnal
Live in social groups
Narrow noses
Larger bodies
Spend more time on the ground
Some do not have tails
Most have opposable digits

16. How do apes differ from monkeys?
Classified into two groups:
1. Lesser apes ( gibbons and siamangs)
2. Greater apes (orangutans, gorillas,chimpanzees, and humans)
Larger brains
Arms are longer than legs
Barrel-shapped chests
No tails
Flexible wrists
Highly sociable
Make complex sounds

17. How do lesser apes travel through the trees?
Brachiation – using a hand-over-hand swinging motion

18. How do great apes walk? Gorillas Chimpanzees and bonobos Orangutans
Largest arboreal primates
Large males spend more time on the ground
Live exclusivity In Asia
Gorillas
Largest primates
Spends most of its time on ground
Walk on all four limbs
Chimpanzees and bonobos
Knuckle walkers
Well-developed communication and social systems
More like human in physical structure and behavior than other primates

19. To what category do humans belong to ?
Humans are part of the greater apes family
Classified as hominins
Hominins are human like primates that appear to be closely related to present day humans than they are to present-day chimpanzees and bonobos
Humans are the only species of hominins that exist today, others extinct

20. Primate evolution
As we discussed in earlier slides most primates today have some common traits
Are arboreal
Have prehensile tails
Long limbs
Binocular vision
Brachiation
Opposable toes and thumbs
* with these traits primates are better adapted to live in trees

21. How might have primates become arboreal?
Scientist suggest that primates have evolved from land-living animals that gathered their food from the top branches of various shrubbery.
This suggest that the opposable thumbs and flexible hands of primates may have evolved to catch food rather than to hold onto tree branches.
Other scientist suggest that the rise of flowering plants provided new niches for primes to evolve to.
Arboreal adaptations enabled primates to gather fruits and flowering trees.
*A niche refers to the way in which an organism fits into an ecological community or ecosystem. Through the process of natural selection, a niche is the evolutionary result of a species' morphological (morphology refers to an organism's physical structure), physiological, and behavioral adaptations to its surroundings.

22. When did the first primates appear?
It is believed that the first primates lives alongside the dinosaurs about 85 mya.
One of the earliest fossil primates, called Altiatlasius (al tee aht lah SEE us), was a small, nocturnal animal that used its hands and feet for grasping.
About 50 mya, anthropoids branched off from tarsiers. At the end of the Eocene, 35 to 30 mya, anthropoids had evolved widely.

23. When did different lines of monkeys diverge?
Monkeys first appeared at the end of the Eocene between 35 and 25 mya.
By this time, Africa and South America had separated into two continents.
Some scientist believe that New world monkeys evolved from a group of old world monkeys that drifted to S.America on rafts of vegetation.
Other scientists believe that new world monkeys branched from anthropoids that traveled to S.America earlier when sea levels were low.

24. What animal might have given rise to apes?
Many anthropoids fossils have been found in the fayum basin in Egypt.
Aegyptopithecus (ee gypt oh PIH thuh kus) or the dawn ape, is the largest (size of house cat)
Some scientist believe that this animal was part of the anthropoid line that splits from old world monkeys.
This line led to orangutans, gorillas, chimps, and humans.

25. Hominoids to hominins

26. *Include all nonmonkey anthropoids:
gibbons
Orangutans
Chimps
Gorillas
Humans.
Hominoids
By comparing DNA of living hominoids species, researchers conclude that gibbons likely branched from anthropoids first.
Next to the branch were orangutans, gorillas, chimps, and bonobos, and finally humans.
*chimps and bonobos are the closest living relatives to humans.

27. What characteristics to hominoids share ?
Largest primates
Largest brains for body size
Broad pelvis
Long fingers
No tail
Flexible arm and shoulder joints
Upright posture
All but hominins have longer arms and legs
Less specialized teeth ( can eat a variety of food)

28. Hominins Include humans and all their extinct relatives.
Split from other African apes between 8 and 5 mya.
Larger than those of other hominoids and have more capacity for high- level thought.
Faces are thinner and flatter
Teeth are smaller
Longer thumbs and more flexible wrists (inc. manual dexterity)

29. What structures support upright walking?
Bipedal- Walk upright on two legs
* notice the shape of the spine , arms, pelvis, and legs.
Why did hominins become bipedal?
Scientist suggest this was an adaptation to the new savanna environment. Individuals now could hold thing in their arms and travel longer distances and reach food better.

30. Human ancestry

31. The homo genus The genus Homo includes all humans living and extinct
Members of this genus first appeared in Africa between 3 and 2.5 mya.
Scientist think they evolved from an australopithecine ancestor.
Homo species had bigger brains than australopithecines along with
bigger skeletons
Flatter faces
smaller teeth.
Homo was the first genus to
Control fire
Use stone tools
Develop language and culture.

32. How did homo habilis differ from its ancestors?
Another species Homo Rudolfensis, might have lived at the same time.
*however few fossils of this species exist
and they are uncertain how this species is related to the homo line.
Was the first homo species for which fossils exist.
Means “handy man”
They used stone tools.
Homo traits of H.habilis included
Larger brains
Smaller brow and jaw
Flatter face
Human like teeth
Like its australopithecine ancestors it was small, had long arms, and could climb trees.

33. Why is homo ergaster important?
*This species only existed briefly in the fossil record.
Why is homo ergaster important?
Tools
H.Ergaster made hand axes and other tools
Might have been a hunter or a scavenger
*Tools might have been used to scrape meat off bones.
Migration
H.Ergaster appeared to be the first African Homo species to migrate to Asia and Europe ( maybe following migrating animals)
Forms of H.Ergaster in Erope and Asia are called Homo Erectus.
It had a large brain than H. Habilis and was
Taller
Lighter
had longer legs and shorter arms
Scientist believe that H. Ergaster had the first human like nose (nostrils facing downward)

34. What skills did homo erectus have?
*In Europe and Asia this species evolved from H.Ergaster.
This species included “Java Man” discovered in Indonesia, and “Peking Man” discovered in China.
This species adapted to many environments.
Erectus as taller than habilis
Had a bigger brain and more human like teeth
Featured a longer skull, low forehead, and a thick brow ridge.
Made advanced tools, used fire, and lived in caves.
Java man
Peking man

35. What is the significance of homo floresiensis?
Scientist believe that H. Erectus went extinct about 400,000 years ago.
* fossils discovered in Indonesia suggest otherwise. (2004)
This species, called H. floresiensis (flor eh see En sus) descended from H. erectus or another hominin.
Existed till about 12,000 years ago.
Nicknamed “ the hobbit” H.Floresiensis was only about 1m tall.
*basic stone tools was found with its fossils

36. What traits did homo heidelbergensis display?
Transition from H. ergaster to modern humans occurred gradually.
Some fossils display a mix of traits of H.ergaster and modern day humans.
* scienctist classify these as Homo Heidelbergensis , others place them in a broad category called Homo sapiens.
These humans had larger brains and thinner bones than H. ergaster, but still had think brow ridges and small chins.

37. Are Neanderthals our ancestors?
*Neanderthals (H. Neanderthalensis) were a species that only evolved in Europe and Asia.
Likey evolved from H.erectus or a homo species of the transitional period.
Lived about 30,000 years ago.
They were larger than humans and had large brains
Had thick skulls and brow ridges, large noses, and heavy muscles attached to their thick bones.
Lived near the end of the Pleistocene ice age.
Hunted, used fire, and made complex shelters for themselves.
Evidence shows that they cared for their sick and buried their dead.
Some evidence suggest that Neanderthals overlapped with modern humans.
DNA tests on fossil bones show that Neanderthals were not part of the human gene pool. They actually were not part of the human gene pool at all and were an entirely different species.

38. Emergence of modern humans

39. Homo Sapiens
Characteristics:
Thinner skeletons ( more slender appearance)
Rounder skulls
Smaller faces (w/ obvious chin)
First appeared in what is now Ethiopia about 195,000 millions of years ago.
Early members of this species chips stones to make hand axes and other tools.

40. What is the “out of Africa” hypothesis ?
Many hominin species overlapped until about 30,000 years ago. Then, only modern humans remained.
The out of Africa hypothesis suggest that humans evolved only once, in Africa, and then migrated to all the parts of the world, replacing other hominins.

41. How did dna support this hypothesis ?
*Mitochondrial DNA changes very little over time.
Mitochondrial DNA analysis of today’s humans supported this hypothesis.
As a result, scientist reasoned that populations with the most variation in this DNA must have exists the longest time.
The widest variation was found among Africans.
Mitochondrial DNA is only inherited from the mother.
Therefore, this analysis suggest that H. Sapiens emerged in Africa about 200,000 years ago from a hypothetical “mitochondrial eve”

42. What evidence of human culture appeared ?
Unlike Neanderthals, modern humans expressed themselves using symbols and art.
They drew on cave walls and decorated objects
Developed complex tools and weapons.
They were the first to fish, make clothes, and raise animals.
These expressions marked the first fully modern humans.
*some people consider Cro-Magnons to be the first hunter-gatherers.