Human Evolution

studied byStudied by 0 people
0.0(0)
Get a hint
Hint

What is the classification of apes?

1 / 73

encourage image

There's no tags or description

Looks like no one added any tags here yet for you.

74 Terms

1

What is the classification of apes?

Apes are divided into Lesser Apes (e.g., Gibbons) and Great Apes, which include Orangutans, Gorillas, Chimpanzees, and Bonobos.

New cards
2

What are the shared derived characteristics of apes?

Apes have relatively large brains, no tails, more erect posture, increased flexibility in hips, ankles, wrists, and thumbs, and adaptations in arm and shoulder structure.

New cards
3

What evidence supports the common ancestry between humans and apes?

Morphological evidence (shared derived traits) and molecular analyses provide strong support for the evolutionary relationship.

New cards
4

What is the key evidence for the phylogenetic relationship between humans and great apes?

Cladistic analyses of both morphological and molecular data highlight the close relationship, especially between humans and African great apes.

New cards
5

What are some unique derived morphological traits of humans compared to other apes?

Humans have elongated skulls, enlarged brow ridges, shortened canines, changes in upper jaw, wrist bone fusion, and reduced hairiness.

New cards
6

What is the genetic difference in karyotypes between humans and African great apes?

Humans have 23 pairs of chromosomes, while African great apes have 24 pairs

New cards
7

How genetically similar are humans and chimpanzees?

The average genetic similarity is 98.77% similarity, with 35 million base pair differences and around 5 million insertion/deletion differences.

New cards
8

What genetic changes are associated with human-specific traits like bipedalism and language?

the FOXP2 gene

New cards
9

What is the significance of HAR1 in human evolution?

HAR1 is involved in brain development, particularly in the cerebral cortex, and has evolved rapidly in humans compared to other primates.

New cards
10

What is the estimated time of divergence between humans and chimpanzees?

5.4 million years ago

New cards
11

What are hominids?

Hominids refer to any species more closely related to humans than to chimpanzees.

New cards
12

Have any chimpanzee fossils been found?

No chimpanzee fossils have ever been found.

New cards
13

What is significant about the Sahelanthropus tchadensis fossil?

It is a single fossil skull dating back 6-7 million years, discovered before the divergence of hominids and chimpanzees.

New cards
14

Where and when was Sahelanthropus tchadensis discovered?

Found in the Djurab Desert of Chad in July 2001.

New cards
15

What is notable about the braincase size of Sahelanthropus tchadensis?

It has a small braincase, smaller than any known hominid and comparable to a chimpanzee.

New cards
16

What was initially thought about the facial structure of Sahelanthropus tchadensis?

Initially thought to have a relatively flat face, later found to be distorted during fossilization

New cards
17

What do most scientists currently consider Sahelanthropus tchadensis to be?

An ape, not a hominid, reflecting advancements in human paleoanthropology

New cards
18

What is a common misconception about human evolution?

That humans are descended from apes; in reality, hominids and modern apes share a common ancestor.

New cards
19

What major trend is observed in cranial capacity over time?

There is a clear trend of increasing cranial capacity, indicating larger brain sizes.

New cards
20

What ongoing disagreement exists among scientists regarding hominids?

The number of distinct genera and species of hominids and their relationships to one another due to a sparse fossil record.

New cards
21

What challenges do taxonomists face when classifying hominid fossils?

Limited sample sizes make it difficult to determine whether variations represent different species or just variations within a single species.

New cards
22

Why are analyses of hominid fossils often focused on skull and tooth characters?

They have a more complete fossil record compared to other skeletal parts

New cards
23

What was the objective of Collard and Wood's analysis?

To reconstruct the phylogeny of living apes using cladistic analysis based on skull and tooth characters.

New cards
24

How many hominid species are recognized, and how are they classified?

Approximately 20 hominid species are recognized, classified into six genera, including Homo (modern humans).

New cards
25

Where is the origin of hominids believed to be?

Hominids are widely accepted to have originated in Africa, with recognized fossils found exclusively there.

New cards
26

What is Orrorin tugenensis?

The only species in the genus Orrorin, known from fossils of at least five individuals.

New cards
27

Where were Orrorin fossils discovered and how old are they?

Discovered in the Tugen Hills of Kenya, dated between 6.1 and 5.8 million years ago.

New cards
28

What suggests Orrorin tugenensis may have walked upright?

The structure of its femur bone indicates a probable bipedal habit.

New cards
29

What are the dental characteristics of Orrorin tugenensis?

Small molars with rounded cusps and small canines, typical of hominids.

New cards
30

What type of environment did Orrorin tugenensis inhabit?

A dry evergreen forest environment, contrasting with previous beliefs about bipedalism evolution.

New cards
31

What genus do the next oldest fossil hominids belong to?

Ardipithecus, with two recognized species.

New cards
32

What key fossil was discovered for Ardipithecus ramidus?

A relatively complete fossil nicknamed "Ardi," discovered in Ethiopia.

New cards
33

When did A. ramidus live, and what does it indicate about locomotion?

Lived about 4.4 million years ago; showed facultative bipedalism, walking on the ground and climbing in trees

New cards
34

What dietary implications are suggested by the teeth of A. ramidus?

An omnivorous diet, more generalized than that of modern apes.

New cards
35

What is Australopithecus?

An early hominid genus that appears later in the fossil record and shows advanced characteristics compared to earlier hominids.

New cards
36

How many species of Australopithecus are recognized?

7 species

New cards
37

Where have all recognized Australopithecus species been found?

Exclusively in Africa.

New cards
38

What is the most famous fossil of Australopithecus?

The almost complete skeleton of Australopithecus afarensis, nicknamed Lucy.

New cards
39

What are some primitive traits of Australopithecus afarensis?

Lower facial projection, relatively large canines, long arms compared to legs, and a smaller brain size.

New cards
40

What bipedal adaptations are observed in Australopithecus afarensis?

Pelvis and leg structure indicating bipedal locomotion and curved finger and toe bones for climbing.

New cards
41

What significant evolutionary split occurred after Australopithecus afarensis?

The split led to two lineages: Slender Australopithecines (leading to modern humans) and Robust Australopithecines (leading to Paranthropus).

New cards
42

Which species are considered intermediates between Australopithecus and Homo?

Homo ergaster, Homo rudolfensis, and Homo habilis.

New cards
43

What are the key anatomical features of early modern humans (Homo sapiens)?

Larger brain size, thinner skull walls, flat forehead, reduced brow ridges, and smaller teeth.

New cards
44

What important behavioral developments occurred in Homo heidelbergensis?

Use of fire, hunting tools, and shelter construction.

New cards
45

When did early modern humans migrate out of Africa?

By 115,000 years ago to South Africa and by 180,000 years ago to Israel.

New cards
46

What significant fossil represents early modern humans?

A 195,000-year-old fossil from Ethiopia showing early changes in skull structure - Omo 1

New cards
47

When did the evolutionary split between Neanderthals and Homo sapiens occur?

Between 400,000 and 500,000 years ago.

New cards
48

What skeletal features are notable in Neanderthals?

They had denser bones, thicker skulls with projecting brow ridges, a distinct bump on the back of the skull, and overall physical similarities to modern humans.

New cards
49

Were Neanderthals and Homo sapiens capable of interbreeding?

Yes, they were anatomically similar enough to interbreed, though it was not frequent.

New cards
50

How long did Homo sapiens coexist with Neanderthals?

For several thousand years in parts of Europe.

New cards
51

When did Neanderthals go extinct?

Approximately 30,000 years ago.

New cards
52

When and where were the fossils of H. floresiensis discovered?

In 2003 in a cave on the island of Flores, Indonesia.

New cards
53

What is unique about the stature of H. floresiensis?

It measured about 3 feet 6 inches in height and had a very small brain, earning it the nickname "the hobbit.

New cards
54

What distinctive physical features set H. floresiensis apart?

A receding forehead, lack of a chin, and distinctive wrist bones.

New cards
55

What is the current understanding of the phylogenetic placement of H. floresiensis?

It remains uncertain, but it may have descended from Homo erectus.

New cards
56

What does local folklore on Flores speak of?

An ancient small human-like creature called Ebu gogo, thought to still exist in the 17th century.

New cards
57

How did brain size evolve in the hominid lineage?

It did not occur uniformly; some periods saw rapid changes in brain size.

New cards
58

What selective pressures may have driven the evolution of bipedalism?

To free the arms for carrying food back to social units, especially to mates and offspring.

New cards
59

How did teeth evolve in response to diet?

Smaller teeth of a more even size evolved due to changes in diet.

New cards
60

What is the Geographic Distribution of Early Hominoids?

All hominoid species up to Homo erectus were primarily restricted to Africa, with diversity centered in the African Rift Valley (Ethiopia, Kenya, Tanzania).

New cards
61

What were environmental conditions for Early Hominoids?

The African Rift Valley was wetter during the time of early hominoids, likely featuring greater forest cover and diverse habitats.

New cards
62

What is the significance of Homo erectus?

Homo erectus represents a significant evolutionary advancement and was the first Homo species to appear outside Africa.

New cards
63

What is the fossil distribution of Homo erectus?

Oldest Homo erectus fossils found almost simultaneously in Africa, Europe, and Asia, dating to approximately 1.9 to 1.6 million years ago.

New cards
64

What is the evolutionary lineage of Homo erectus to Homo sapiens?

Homo erectus is a direct ancestor of Homo sapiens. Homo heidelbergensis and Homo neanderthalensis may represent stages in this lineage or side branches.

New cards
65

Where was the first Homo sapiens fossils found?

Earliest fossils date back to approximately 130,000 years ago in Africa, with migrations outside Africa evidenced in Israel around 100,000 years ago.

New cards
66

What is controversy in the Origin of Homo sapiens?

Various hypotheses exist regarding the transition from Homo erectus to Homo sapiens, including the Out of Africa and Multiregional models.

New cards
67

What is the Out of Africa Model?

Proposes anatomically modern humans originated in Africa around 200,000-130,000 years ago, migrating out around 60,000 years ago, replacing other Homo species.

New cards
68

What is the Multiregional Hypothesis?

Suggests Homo sapiens emerged from four lineages of Homo erectus in Africa, Europe, Asia, and Australia, with hybridization maintaining a single species.

New cards
69

What is evidence that supports the African Replacement model?

Current human genetic diversity is greater in Africa, and genetic differences among populations outside Africa suggest colonization by a small number of individuals.

New cards
70

When is the last common ancestor dated?

The last common ancestor of African and non-African populations is dated to approximately 52,000 years ago, supporting the African Replacement Model.

New cards
71

Interbreeding of Homo sapeins and Neandethals caused what genome % to be found in non-Africans?

1-4%

New cards
72

What are some insights into Neanderthal Appearance?

Genomic analysis suggests Neanderthals likely had pale skin and red hair, advantageous for vitamin D synthesis in low sunlight regions.

New cards
73

What were the migration pathways of early humans?

Early humans migrated out of Africa via two main routes; colonization of the Americas occurred from Siberia across the Bering Strait during the last ice age.

New cards
74

What is the molecular evidence that suggests the African Replacement model?

DNA evidence shows that people within Africa have the highest degree of genetic diversity and the farther one travels from the continent, the less genetically diverse the population.

<p><span>DNA evidence shows that people within Africa have the highest degree of genetic diversity and the farther one travels from the continent, the less genetically diverse the population. </span></p>
New cards

Explore top notes

note Note
studied byStudied by 15 people
... ago
5.0(1)
note Note
studied byStudied by 1956 people
... ago
4.9(7)
note Note
studied byStudied by 1 person
... ago
5.0(1)
note Note
studied byStudied by 11 people
... ago
5.0(1)
note Note
studied byStudied by 9 people
... ago
5.0(1)
note Note
studied byStudied by 48 people
... ago
5.0(1)
note Note
studied byStudied by 1128 people
... ago
5.0(2)

Explore top flashcards

flashcards Flashcard (46)
studied byStudied by 19 people
... ago
5.0(1)
flashcards Flashcard (54)
studied byStudied by 9 people
... ago
5.0(1)
flashcards Flashcard (40)
studied byStudied by 6 people
... ago
5.0(1)
flashcards Flashcard (78)
studied byStudied by 6 people
... ago
5.0(2)
flashcards Flashcard (648)
studied byStudied by 24 people
... ago
5.0(1)
flashcards Flashcard (319)
studied byStudied by 15 people
... ago
5.0(1)
flashcards Flashcard (31)
studied byStudied by 28 people
... ago
5.0(1)
flashcards Flashcard (34)
studied byStudied by 33 people
... ago
5.0(1)
robot