human evolution

Question 1

Approximately how long ago did modern humans (Homo sapiens) first appear in Africa?

Answer 1

Around 300,000 years ago.

Question 2

Early dispersals of modern humans around 200,000 years ago may have reached which two locations before these populations died out?

Answer 2

Greece and possibly China.

Question 3

The main dispersal (left africa) event that gave rise to all modern non-African populations occurred approximately how long ago?

Answer 3

Around 70,000 years ago.

Question 4

The gradual movement of early humans out of Africa is estimated to have progressed at what average rate per year?

Answer 4

Approximately 1 kilometre per year.

Question 5

Early human movement out of Africa is described as simply walking, not as a _____, _____, or _____.

Answer 5

colonisation, trek, or expedition

Question 6

What major environmental factor is thought to have driven many of the early human dispersals?

Answer 6

Climate change.

Question 7

How does genetic variation (heterozygosity) in modern populations change with increasing walking distance from East Africa?

Answer 7

It decreases.

Question 8

The pattern of decreasing genetic variation with distance from East Africa reinforces which key concept about human origins?

Answer 8

That all modern humans originate from Africa (“We are all Africans”).

Question 9

Genetic measurements suggest the human population experienced a bottleneck, reducing it to what approximate effective size?

Answer 9

Around 12,000 people.

Question 10

Which archaic humans, such as Neanderthals, left Africa before Homo sapiens?

Answer 10

Earlier hominins.

Question 11

What is the relationship of Neanderthals to modern humans?

Answer 11

They are considered cousins, not ancestors.

Question 12

Neanderthals existed between 400,000 and 30,000 years ago, overlapping with modern humans for up to how many years?

Answer 12

Up to 5,000 years.

Question 13

Evidence from a cave in the Altai mountains suggests what about Neanderthal social structure regarding sex-based dispersal?

Answer 13

Males tended to stay in their birth groups, while females may have moved between groups.

Question 14

The severely worn front teeth of a 50,000 year old male Neanderthal skull suggest they were used for what purpose?

Answer 14

As a ‘third hand’, possibly in the preparation of animal hides

Question 15

Beyond using animal hides, Neanderthals demonstrated sophisticated cultural behaviours such as diving for shells and making what?

Answer 15

string

Question 16

What form of personal adornment, dated to 50,000 years ago, shows evidence of Neanderthal culture?

Answer 16

A shell necklace.

Question 17

Cave art in Gibraltar, dated to 65,000 years ago, predates the arrival of Homo sapiens and is attributed to which archaic human group?

Answer 17

Neanderthals.

Question 18

What practice related to the deceased is considered a cultural trait of Neanderthals?

Answer 18

They buried their dead.

Question 19

What was the estimated total population of Neanderthals across Europe, considered a ‘dangerously small’ number?

Answer 19

Potentially only about four thousand individuals.

Question 20

The discovery of interbreeding between non-Africans and Neanderthals implies they were not separate _____ by biological definition.

Answer 20

species

Question 21

Approximately what percentage of DNA in modern non-African populations is of Neanderthal origin?

Answer 21

Around 3%.

Question 22

A European individual alive 40,000 years ago had an amount of Neanderthal DNA equivalent to that from which recent ancestor?

Answer 22

A great-great-grandparent.

Question 23

Genetic analysis reveals how many amino acid differences between the proteomes of modern humans and Neanderthals?

Answer 23

Only 96.

Question 24

Besides protein-coding changes, how many differences have been identified in regulatory regions between human and Neanderthal genomes?

Answer 24

There are 3117 differences in regulatory regions.

Question 25

Neanderthal genes inherited by modern humans are known to be involved in which two biological traits?

Answer 25

Skin colour and immune response.

Question 26

What was the first physical evidence of Denisovans, discovered in a Siberian cave in 2008?

Answer 26

A 40,000-year-old tooth.

Question 27

Why are the hominins discovered in Denisova cave simply called 'Denisovans'?

Answer 27

Because they hold an unknown taxonomic position.

Question 28

Modern populations in which continent have been found to possess Denisovan genes?

Answer 28

Asia.

Question 29

The presence of Denisovan genes east of Wallace's Line suggests they must have used what form of advanced travel?

Answer 29

Boats, to cross deep sea channels that were never dry.

Question 30

What is the name of the skull found in China, dating from 138,000 to 309,000 years old, that new research suggests could be Denisovan?

Answer 30

The 'Dragon man' skull.

Question 31

The most recent introgression event involving Denisovans may have occurred as recently as how many years ago?

Answer 31

Around 15,000 years ago.

Question 32

Introgression

Answer 32

The transfer of genetic material from one lineage into another through repeated backcrossing after an initial hybridisation event.

Question 33

Which specific allele, associated with high-altitude adaptation, did Tibetans acquire through introgression from Denisovans?

Answer 33

The EPAS1 allele.

Question 34

Besides Neanderthals and Denisovans, genetic evidence suggests that Asian and African populations also interbred with what?

Answer 34

Unknown archaic forms.

Question 35

Due to two single base changes in their DNA, Neanderthals and Denisovans would have had a strong aversion to the smell of what compound?

Answer 35

Androstenone.

Question 36

Genetic analysis of smell receptors suggests Neanderthals were specifically more sensitive to what category of smells?

Answer 36

Sulphurous smells.

Question 37

Genetic analysis of smell receptors suggests Denisovans were more sensitive to smells associated with what substance?

Answer 37

Honey.

Question 38

Genetic analysis shows no sign of introgression in Southeast Asian DNA from any archaic group other than _____.

Answer 38

Denisovans

Question 39

What is the significance of the 2010 sequencing of the Neanderthal genome?

Answer 39

It revealed that non-Africans had interbred with Neanderthals.

Question 40

What is the key characteristic of the 40,000-year-old Denisovan tooth compared to those of modern humans or Neanderthals?

Answer 40

It does not resemble the teeth of either modern humans or Neanderthals.

Question 41

Where is the richest genetic variation (heterozygosity) in human populations found?

Answer 41

In ancestral areas, specifically East Africa.

Question 42

The announcement of the Denisovan _____ in 2011 was described as a 'bombshell' in the field of human evolution.

Answer 42

DNA sequence

Question 43

In Neanderthal family groups from the Altai mountains, what evidence was found alongside the father-daughter DNA?

Answer 43

DNA from prey items.

Question 44

How many single base changes are there between the genomes of modern humans and Neanderthals?

Answer 44

31,389.

Question 45

What key human behaviour is exemplified by the 100,000-year-old ochre 'factory' found in South Africa?

Answer 45

Making art.

Question 46

The Indonesian cave art, dated to 39,900 years old, provides evidence for what key human behaviour?

Answer 46

The creation of art.

Question 47

How does introgression provide an analogy to a 'transfer of technology' in human evolution?

Answer 47

Modern humans inherited pre-tested genetic adaptations from archaic groups, accelerating their ability to thrive in new environments.

Question 48

What did the genomes of 14 Neanderthals from a cave in the Altai mountains reveal about their social structure?

Answer 48

They revealed close relationships, including a father and daughter, suggesting they lived in family groups.

Question 49

What was the estimated total population of Neanderthals across the whole of Europe?

Answer 49

It was dangerously small, possibly around four thousand individuals in total.

Question 50

Based on the biological species concept, were humans and Neanderthals separate species?

Answer 50

No, because they interbred to produce fertile offspring.