Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

From Flashcardlet > Human evolution > Flashcards

Human evolution Flashcards

1
Q

When did primates first evolve from mammalian ancestor?

A

85-65 mya. However earliest fossil is 55 mya. This is at the end of the Cretaceous periode (dinosaurs go extinct)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How do we separate the periods?

A

Environmental changes caused most changes in species. For humans (Pleistocene) it is determined by cooler more variable climate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the continents made up of?

A

Plate tectonics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does continental drift explain?

A

The distribution of species and fossils.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is Paleontology?

A

The study of fossilized remains of plants and animals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Paleoanthropology?

A

The study of fossils from the human lineage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How are fossils made?

A

The minerals in the surrounding area replace the materials in the bone making them as strong as their surroundings.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a phylogeny?

A

The organisation of a lineage and the relationships between species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When did angiosperms arise?

A

65 mya offering new food sources

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Who are the Plesiadapiforms?

A

Mammals closely related to primates 65-54 mya in the paleocone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do plesiadapiforms differ from current primates?

A

Lacked nails, opposable toe, postorbital bar, forward facing eyes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How are plesiadapiforms similar to primates?

A

They were arboreal with very diverse diets that were most likely nocturnal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What supports the terminal branch theory while discrediting the visual predation theory?

A

Grasping hands came before forward facing eyes therefor primates were already in trees eating before the eyes developed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

When did the Euprimates appear?

A

85-54 mya during the Eocene. This was during tropics expansion. (considered true primates)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where were the first Euprimates found?

A

North america and europe. Later everywhere else but south america which was isolated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What features do Euprimates have similar to current primates?

A

Postorbital bar, nails, larger brains (to body size), stereoscopic vision and less olfaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Euprimates split into two families. What are their names?

A

Adapidae and Omomyidae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the characteristics of the Adapidae?

A
  • lemur like
  • arboreal quadrupeds
  • slow arboreal climbers
  • smaller orbits (diurnal)
  • general dentition (general diet)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the characteristics of the Omomyidae?

A
  • smaller galago and tarsier like
  • elongated tarsal bones for leaping
  • nocturnal (large orbits)
  • general dentition (general diet)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Who arose during the Eocene but diversified in the Oligocene>

A

Haplorrhines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is special about the Fayum in egypt?

A
  • large fossil deposits

- currently desert but tropical swamp during the oligocene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What do platyrrhines have in common with catarrhines?

A
  • Postorbital closure
  • fused mandible
  • more forward facing eyes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why are some fossils at Fayum be from NWM?

A

They have 2133 dentition.

24
Q

When did apes first appear?

A

27 mya during the oligocene and dominated during the miocene

25
Q

Who are the two apes found?

A

Morotopithecus bishopi 20mya and Proconsul 27-17mya

26
Q

Information about Morotopithecus bishopi.

A
  • Uganda

- suspensory ape like locomotion due to the shape of the scapula

27
Q

Inforamtion about Proconsul.

A
  • East Africa
  • Lacked a tail
  • larger brain
  • not suspensory
  • mostly frugivores
  • arboreal
28
Q

When did hominoids move to Eurasia?

A

15-10 mya as that is when there would have been a land bridge allowing this.

29
Q

What was the key adaptation in apes?

A

Thicker enamel on molars which allowed them to eat tougher food during hard times

30
Q

Many major groups of hominoids evolved during the middle miocene. Name them and where

A

Afropithecus and Kenyapithecus - Africa

Dryopithecus, Ouranopithecus, Oreopithecus and Pliopithecus - Europe

Sivapithecus and Lufengpithecus - asia

31
Q

Why was there a decline in ape diversity?

A

Climate became drier and large competition with the cercopithecoid monkeys.

32
Q

When did hominins first appear?

A

7-5 mya

33
Q

What are the possible distingusihing traits between humans and apes?

A
  • Brain capabilities
    -Bipedalism
    (bipedalism came before increase in brain size and complexity)
34
Q

Who were the first fossils found in the hominin lineage?

A

Homo erectus in asia and neandrathals in europe.

35
Q

What changed did we see in dentition?

A
  • parabolic dental arcade
  • thick enamel
  • reduced canines
  • larger molars
36
Q

What anatomical changed would need to occur to allow hominins to be fully bipedal?

A
  • center of gravity was lowered
  • limb size increased
  • lumbar curve to allow the top of the body to be in line with pelvis
  • pelvis became wide and short
  • foramen magnum is central in humans but sideways in apes
  • locking of the knees
  • angle of femur
  • foot is made to support weight
37
Q

Changes in the foot to support bipedalism?

A
  • Large heel absorbs shock
  • arch for distributing forces
  • big toe in line with other toes
38
Q

How can we tell early hominins were still partially arboreal?

A
  • longer arms
  • curved fingers and toes
  • big toe relatively abducted
39
Q

What is the most likely cause of the change from arboreal to bipedal?

A

Climate change. Became colder and drier also forest was replaced by flora.

40
Q

Why might bipedalism be considered an exaptation?

A

Bipedal may have originally been for acquiring food or for displays.

41
Q

Bipedal was not great at first. Same energy cost as quadrupedal monkeys. Why else might it have been better?

A
  • reducing heat stress

- freeing hand for carrying objects

42
Q

What is a diastema?

A

Free area between teeth to allow the mouth to close with large canines.

43
Q

What does the diastema allow?

A
  • prevents lateral jaw movement when jaw is closed

- will sharpen the canines

44
Q

What are the characteristics of hominid canines?

A
  • non-projecting
  • small
  • no diastema
45
Q

What are the three pre-australopithecines (early hominins)? (6-4.4 mya)

A
  1. Sahelanthropus tchadensis
  2. Orrorin tugenensis
  3. Ardipithecus ramidus and A. kadabba
46
Q

What are the features of pre-australopithecines?

A
  • bipedal however also arboreal or debatable
  • teeth were primative
  • peri-honing of the molars
  • ape size brains
47
Q

What are the three hominins 4-2 mya?

A
  1. Australopithecus (gracile australopithecines)
  2. Paranthropus (robust australopithecines)
  3. Kenyanthropus platyops
48
Q

When and where was Australopithecus anamensis found?

A

4.2-3.8 mya in Kenya and Ethiopia.

49
Q

What are the derived traits of A. anamensis?

A

Thick enamel and knee and ankle for bipedalism

50
Q

What primitive traits do A. anamensis have?

A 
U-shaped jaw
small diastema
large canines
receding chin
upper limbs still for arboreality
ape like back of skull
small brains (430cc)
- sexually dimorphic
51
Q

Who was special with A. anamensis?

A

Lucy found by Don Johanson in 1974. 3.2 mya, 3’8”

Selam 3 year old 3.5-3.1 mya found in chad.

52
Q

Who found the Laetoli footprints. When and where?

A

Mary Leakey. Tanzania in 1976

53
Q

When was Australopithecus africanus discoved and where?

A

1924 in southern Africa by Dart. 3-2.2mya

54
Q

How does A. africanus compare to A. afarensis?

A
  • slightly larger brain
  • larger body size
  • still sexually dimorphic
55
Q

How does A. africanus compare to humans?

A
  • larger molars

- rapid maturation

56
Q

When was Australopithecus garhi found and where?

A

Ethiopia. Dated back to 2.5mya

57
Q

What are defining characteristics of A. garhi?

A
  • black skull
  • prognathic face
  • sagittal crest
  • brain 450 cc
  • larger teeth than other autralopithecus
  • possible first stone tool producer

From Flashcardlet (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions