Lecture 12.1

Question 1

Why do the gluteal muscles in apes have an extensor role rather than an abductor role in apes?

Answer 1

Head and neck of the femur are smaller in apes than humans meaning bicondylar angle is also smaller and as a result the gluteal muscles perform a different action on the femur.

Question 2

What is the difference in femoral condyle shape between humans and apes?

Answer 2

Femoral condyles in humans are longer and more elliptical. This allows greater articular contact between femur and tibia making this joint more stable.

Question 3

Why do apes have a rounded femoral condyle?

Answer 3

Rounded condyle allows apes to have a more unstable but mobile knee.

Question 4

What is the difference between the tibia and fibula in apes and humans?

Answer 4

Humans have a robust tibia and not as robust fibula. In apes tibia is not as robust but fibula is more robust and mobile.

Question 5

What is the difference in femoral condyle size between humans and apes?

Answer 5

lateral tibial condyle is smaller than the medial condyle in both humans and apes. In apes the difference is bigger than in humans this allows them to do more rotation

Question 6

What is different about foot structure between humans and apes?

Answer 6

Human foot has strong heel and well developed arches. Apes have no arch and feet are used to grab onto branches.

Question 7

What is the function of psoas minor in apes?

Answer 7

Psoas minor inserts oonto pelvis and this helps in maintaining hip flexion (apes always have a flexed hip and flexed knee in their gait)

Question 8

What is the difference between gluteus maximus between humans and apes?

Answer 8

Gluteus maximus has a wider area of insertion compared to humans.

Question 9

What is the origin and insertion of the gluteus maximus in apes?

Answer 9

Gluteus maximus originates at ilium, sacrotuberous and sacrospinous ligaments, and at the sacrum and inserts onto the shaft of the femur.

Question 10

Do apes have a quadratus plantae?

Answer 10

Yes, but in apes the quadratus plantae is frequently absent

Question 11

What is the function of gluteal muscles in apes?

Answer 11

Gluteals are extensors of the thigh in apes.

Question 12

What does fossil evidence indicate about the habitat of homo neanderthalensis?

Answer 12

Homo neanderthalensis were adapted to cold weather

Question 13

What is facial prognathism?

Answer 13

facial prognathism is the projection of the snout

Question 14

How were the size and shape of the rib cage and pelvis different in australopithecus afarensis compared to apes?

Answer 14

australopithecus afarensus had a cone shaped rib cage combined with a pelvis that’s shorter.

Question 15

When did homo species evolve?

Answer 15

2 million years ago the more modern human features began to appear. (first homo species began to exist)

Question 16

How are the cervical vertebrae different in australopithecus afaresnsis different to modern humans?

Answer 16

Australopithecus afarensis have long- non bifid spinous processes.

Question 17

What curvature could be seen in Australopithecus’ spines?

Answer 17

australopithecus afarensis had thoracic kyphosis.

Question 18

In what way is the spine in A. africanus similar to apes?

Answer 18

A. africanus had 6 lumbar vertebrae

Question 19

Did humans or neanderthals have a larger lumbar lordosis?

Answer 19

Lumbar lordosis in neanderthals was larger than in humans

Question 20

How was the intermembral ratio different in homo and australopithecus species different?

Answer 20

intermembral ratio in early homo species is very similar to homosapiens and A. species are closer to apes

Question 21

What structure do australopiths share with knuckle walkers?

Answer 21

Early australopiths have remnant (perhaps vestigial) ridges on their posterior radius

Question 22

Were neanderthals able to perform precision and power grips?

Answer 22

Saddle joint in neanderthals is not as efficient as modern humans. Precision grip was not possible but power grip was.

Question 23

Why can it be hypthesized that A. afarensis gave assisted births?

Answer 23

A. afarensis has a narrow pelvic inlet.

Question 24

What features did the neanderthal pelvis compared to humans?

Answer 24

A more anterior sacrum

A wider pelvis

A long pubis

Question 25

Did humans or neanderthals have a bigger cranial capacity?

Answer 25

Neanderthals had a bigger cranial capacity