Hominins - The Fossil Record.

Question 1

How is genetics used to provide evidence of evolutionary relationships between different populations?

Answer 1

By comparing DNA.

Question 2

How can we determine when a species or population became isolated?

Answer 2

By comparing rates of mutation. Molecular clock.

Question 3

What is the molecular clock?

Answer 3

Mutations occur at a constant rate which allows one to determine the time between a split and the common ancestor.

Question 4

Complications when determining a species based on a fossil.

Answer 4

There may be a single piece of fossil evidence of this species, Distinctions are made on partial skeletons - could it be part of an already known species?

Question 5

How do Africans share genome with Neanderthals?

Answer 5

Arid conditions caused humans to migrate out of Africa. Once they did, they began to interbreed with Neanderthals. They then migrated back to Africa.

Question 6

What is the earliest know hominin?

Answer 6

Sahelanthropus tchadensis: found 6 -7 mya.

Question 7

What is the earliest known bipedal hominin?

Answer 7

Orrorin tugenesis - 5 -6 mya

Question 8

Age Ardipithecus ramidus. What further development is this hominin’s skeleton evidence of?

Answer 8

4.5 - 4.3mya, this hominin had a toe that was still opposable but not adapted for knuckle walking.

Question 9

Who were the fully bipedal hominins? Why are they so special?

Answer 9

The Australopithecines. There were several species found in Africa, and some are believed to be in the human line.

Question 10

What species showed the first use of stone tools? How long ago?

Answer 10

Australopethicus afarensis - 3.3mya - Cut marks in antelope show they used stone to access marrow.

Question 11

Which hominin species has more human species than afarensis?

Answer 11

Astralopethicus africanus - dated 3.3 - 2.1mya - supports theory humans evolved in Africa.

Question 12

What is the genus that is close to Australopithecus?

Answer 12

Paranthropus.

Question 13

What similarities did Paranthropus bosei have with australopethicus? What were their differences?

Answer 13

Similarities: Sexual dimorphism,
Differences: Robust skull and build, large molars bosei, herbavorous diet in bosei.

Question 14

The first of the homo genus to evolve? Date? Describe tools found with these fossils.

Answer 14

Homo habilis. 2.4 - 1.6mya. Tools associated with this genus were much more advanced than Australopithecus tools, with evidence of flint knapping.

Question 15

What is the second homo genus to evolve? Describe body, possible descendant, and tools.

Answer 15

Homo ergaster 1.9 - 1.5mya. Possible ancestor to homo erectus. Bone structure is finer. Hand axes more defined, and this technique was used for a million years.

Question 16

What could have evolved alongside stone tool making? How?

Answer 16

Speaking/language - because stone tool making uses the same brian patterns as speaking.

Question 17

What suggests neuroplasticity?

Answer 17

Differences in brain activity of different skill levels.

Question 18

Which hominin genus was the first to be identified outside of Africa?

Answer 18

Homo erectus.

Question 19

Date homo erectus, state fossils found that suggest sophisticated behaviour, Where they were found, and stature.

Answer 19

1.8 - 0.3mya, more sophisticated tools and presence of symbolic or aesthetic artefacts, they were widespread, they had fully modern bipedalism.

Question 20

How do we know homo genus didnt settle or evolve in asian countries?

Answer 20

Asian sites lack hand axes.

Question 21

Which homo genus is considered the archaic homo?

Answer 21

Homo heidelbergensis

Question 22

Facts about the heidelbergensis:
Date
Tools
Fossil location
Phylogenetic link
Diet

Answer 22

600,000 - 450,000 ya
Finely made hand axes and spears
Africa and Europe - link between neanderthals and humans.
Large animals - skilled large animal hunter.