Early hominids

Question 1

Hominids

Answer 1

The family of primates that includes humans and our ancestors since we diverged from our last common ancestor with chimpanzees- About 6 million years ago.

Question 2

Hominins

Answer 2

Classification based on molecular evidence.

Question 3

Human dental composition

Answer 3

The modern human dental arcade is more rounded in a parabolic arch unlike an apes, reflecting the smaller anterior teeth (canines and incisors) and posterior (premolars and molars).

Question 4

Ape dentition

Answer 4

In apes the dental arcade us more U- shaped and the teeth behind the canines forming two parallel lines. This is a result of the large canines that apes possesses.

Question 5

Early hominids dentition

Answer 5

Early hominids have a relatively U- shaped dental arcade but their anterior teeth are somewhat smaller than those of apes.

Question 6

Facial prognathism

Answer 6

The size and shape of the anterior teeth have a large impact on the shape of the face. The facial prognathism is the degree to which the face projects outward from the braincase. Large anterior teeth contribute to greater facial proganthism, the face of early hominids have a rather projecting face like that of apes.

Question 7

Homodont

Answer 7

Teeth that all look alike and have the same function- grabbing and boring down on food. Common in lower vertebrates such as fish and lizards.

Question 8

Heterodont

Answer 8

Mammals have this kind of dentition. There are different kinds of tooth that each have a specific function.

Question 9

CP3

Answer 9

This composition in the teeth can be used to differentiate between fossil apes and fossil hominids. In monkey and apes the canines in the maxilla must fit in to the tooth row in the mandible. Due to this they slide past the 3rd premolar- although in apes its the front premolar as the 1st and 2nd were lost during evolution. The canine is sharpened by the blade like P3. As the canine shortens during evolution, the blade of the P3 disappears and the canine changes from having 1 cusp to 2.

Question 10

Enamel

Answer 10

African apes have thin enamel where ours is thick. Early hominids have thicker enamel than apes. This can be useful as an identifier of fossilised hominids- Although thick enamel may’ve come around several times during primate evolution as an adaptation to the food groups being eaten. Therefore, thick enamel is not a guarantee that it’s an hominid tooth.

Question 11

Brain size and cranial proportions

Answer 11

Although early hominids have ape-sized brains, throughout hominid evolution brain size has been increasing while face size decreased- in part due to a reduction in the anterior teeth and masticatory system with an added emphasis on brain size and intelligence.