Question 1

When Rebecca Cann decided to conduct research on the evolution of humans, she chose to study mitochondrial DNA. Which of the following explains why she chose this type of DNA?

Accepted Answer

Mitochondrial DNA is more abundant in cells compared to nuclear DNA, making it easier to extract for research purposes. This abundance is particularly useful in studies of ancient DNA, where sample quality may be compromised.

Question 2

Comparison of mtDNA sequences revealed that all humans shared a common mtDNA ancestor around 200,000 years ago. What was the predicted date of the common ancestor under the multiregional hypothesis of modern human origins?

Accepted Answer

The multiregional hypothesis of modern human origins posits that modern humans evolved from earlier human species starting around 2,000,000 years ago, with continuous gene flow between geographically separated populations. This contrasts with the "Out of Africa" model, which suggests a more recent common ancestor.

Question 3

Based on Figure 24.10, which of the following statements is TRUE?

Accepted Answer

The answer of Based on Figure 24.10, which of the...

Question 4

All evidence suggests that the Neanderthals did not interbreed with our ancestors.

Accepted Answer

Recent studies have found that modern humans share 1-4% of their DNA with Neanderthals, indicating that there was interbreeding between the two species.

Question 5

Interbreeding between Neanderthals and modern H. sapiens likely took place in _____ around _____ years ago, before H. sapiens spread around the world.

Accepted Answer

Interbreeding between Neanderthals and modern H. sapiens likely occurred in the Middle East around 60,000 years ago, before H. sapiens spread globally. This is supported by genetic evidence showing Neanderthal DNA in people outside Africa.

Question 6

Many researchers hypothesize that modern humans have derived from the Homo ergaster populations that spread around the world starting about 2 million years ago. This hypothesis is known as the:

Accepted Answer

The answer of Many researchers hypothesize that modern humans have...

Question 7

Approximately what percentage of non-African human nuclear DNA genomes are Neanderthal derived?

Accepted Answer

The correct answer is B) 1-4%. Studies have shown that about 1-4% of the DNA of non-African modern humans is derived from Neanderthals, indicating interbreeding between Neanderthals and early modern humans outside of Africa.

Question 8

Approximately what percentage of modern human mtDNA is Neanderthal derived?

Accepted Answer

There is currently no evidence that Neanderthal mtDNA has been integrated into modern human mtDNA.

Question 9

The mitochondrial DNA study indicated that there was no genetic input from Neanderthals in modern humans, but the whole-genome study suggests that in fact there was. One suggestion to explain this discrepancy is that the Neanderthal input into modern human populations was from males only. Which of the following strategies could be employed to test this hypothesis?

Accepted Answer

Looking at the Y chromosome would be the best choice because it is paternally inherited, meaning it is only passed down from fathers to sons. Therefore, if there was Neanderthal genetic input from males only, it would be detectable on the Y chromosome.

Question 10

Genetic sequence data from mitochondrial and Y chromosome DNA agree that the human family is _____ and it arose _____.

Accepted Answer

Genetic evidence from mitochondrial DNA, which is passed from mother to child, and Y chromosome DNA, passed from father to son, supports the idea that the human family is relatively young in evolutionary terms and that it originated in Africa.

Question 11

Mitochondrial DNA studies were used to determine that Homo sapiens evolved in Africa and only later did they become established elsewhere.

Accepted Answer

Mitochondrial DNA studies have shown that all non-African populations derive from a subset of African individuals who migrated out of Africa around 60,000-70,000 years ago. This supports the theory that Homo sapiens evolved in Africa before spreading to other parts of the world.

Question 12

If the out-of-Africa hypothesis of human origins is correct, which of the following BEST describes the pattern of hominin migration from Africa?

Accepted Answer

The out-of-Africa hypothesis suggests that Homo ergaster (an early human ancestor) migrated out of Africa around 2 million years ago, and Homo sapiens (modern humans) migrated out of Africa around 60,000 years ago. This pattern reflects a significant gap in time between the migrations of these two species, supporting the idea of multiple waves of hominin migration out of Africa.

Question 13

Why do we only see Neanderthal input in non-African genomes?

Accepted Answer

Neanderthals and Homo sapiens interbred outside of Africa, after Homo sapiens migrated out of Africa. Neanderthals primarily inhabited Europe and parts of Asia, so their genetic input is found in the genomes of non-African populations due to interbreeding in these regions.

Question 14

Which of the following properties of mitochondrial DNA (mtDNA) is NOT helpful in using mtDNA to infer the geographic origin and timing of the evolution of modern humans?

Accepted Answer

All of the other properties listed are helpful in using mtDNA to infer the geographic origin and timing of the evolution of modern humans. Uniparental inheritance of mtDNA from the mother allows for tracing maternal lineages, mutations that occur at a constant rate over time allow for estimating the time since divergence from a common ancestor, lack of recombination allows for tracing mtDNA lineages through time, and the large number of mitochondria in a typical cell makes mtDNA sequencing easier. However, the presence of more than one mitochondrial genotype in rare cases can complicate the interpretation of mtDNA data.

Question 15

According to the multiregional hypothesis of human origins, modern H. sapiens evolved by _____ from _____ of H. ergaster.

Accepted Answer

The multiregional hypothesis suggests that modern Homo sapiens evolved from Homo ergaster through a process of convergent evolution in multiple Old World populations, rather than originating from a single African population.

Question 16

According to genetic analyses, approximately _____% of the genome of every non-African is derived from Neanderthals.

Accepted Answer

Genetic analyses indicate that approximately 1-4% of the genome of every non-African is derived from Neanderthals. This indicates that interbreeding between Neanderthals and modern humans did occur, and that some of the DNA from Neanderthals has been passed down to modern humans.

Question 17

Sequences in mtDNA and the Y chromosome provide an interesting perspective on the early migratory routes of H. sapiens. Both mtDNA and Y chromosome data are useful because these molecules do not undergo recombination. Which of the following statements also provides support for their utility in estimating origins of various groups within H. sapiens?

Accepted Answer

mtDNA and the Y chromosome can indeed provide insights into interbreeding events between different Homo species due to their mode of inheritance—mtDNA is maternally inherited and the Y chromosome is paternally inherited. This allows for the tracing of lineage and interbreeding events across generations.

Question 18

Of the taxa listed below, which of the following nonmodern humans was the LAST to go extinct?

Accepted Answer

Homo floresiensis is believed to have gone extinct around 50,000 years ago, which is more recent than the extinction of Neanderthals (around 40,000 years ago) and much later than Homo habilis and Cro-Magnon.

Question 19

Which of the following statements is NOT correct regarding the multiregional and out-of-Africa hypotheses for the origin of modern humans?

Accepted Answer

The multiregional hypothesis does not predict that African samples would form a monophyletic group; instead, it suggests continuous gene flow among populations in different regions, which would not result in a clear monophyletic grouping of African samples.

Question 20

Cro-Magnon is the name of the group of the first Neanderthals found in Europe.

Accepted Answer

Cro-Magnon is not the name of the group of the first Neanderthals found in Europe. Cro-Magnon refers to the early modern humans who lived in Europe approximately 40,000-10,000 years ago.

Quiz 24: Human Origins and Evolution

When Rebecca Cann decided to conduct research on the evolution of humans, she chose to study mitochondrial DNA. Which of the following explains why she chose this type of DNA?

Comparison of mtDNA sequences revealed that all humans shared a common mtDNA ancestor around 200,000 years ago. What was the predicted date of the common ancestor under the multiregional hypothesis of modern human origins?

Based on Figure 24.10, which of the following statements is TRUE?

All evidence suggests that the Neanderthals did not interbreed with our ancestors.

Interbreeding between Neanderthals and modern H. sapiens likely took place in _ around _ years ago, before H. sapiens spread around the world.

Many researchers hypothesize that modern humans have derived from the Homo ergaster populations that spread around the world starting about 2 million years ago. This hypothesis is known as the:

Approximately what percentage of non-African human nuclear DNA genomes are Neanderthal derived?

Approximately what percentage of modern human mtDNA is Neanderthal derived?

Genetic sequence data from mitochondrial and Y chromosome DNA agree that the human family is _ and it arose _.

Mitochondrial DNA studies were used to determine that Homo sapiens evolved in Africa and only later did they become established elsewhere.

If the out-of-Africa hypothesis of human origins is correct, which of the following BEST describes the pattern of hominin migration from Africa?

Why do we only see Neanderthal input in non-African genomes?

Which of the following properties of mitochondrial DNA (mtDNA) is NOT helpful in using mtDNA to infer the geographic origin and timing of the evolution of modern humans?

According to the multiregional hypothesis of human origins, modern H. sapiens evolved by _ from _ of H. ergaster.

According to genetic analyses, approximately _____% of the genome of every non-African is derived from Neanderthals.

Of the taxa listed below, which of the following nonmodern humans was the LAST to go extinct?

Which of the following statements is NOT correct regarding the multiregional and out-of-Africa hypotheses for the origin of modern humans?

Cro-Magnon is the name of the group of the first Neanderthals found in Europe.

Quiz 24: Human Origins and Evolution

When Rebecca Cann decided to conduct research on the evolution of humans, she chose to study mitochondrial DNA. Which of the following explains why she chose this type of DNA?

Comparison of mtDNA sequences revealed that all humans shared a common mtDNA ancestor around 200,000 years ago. What was the predicted date of the common ancestor under the multiregional hypothesis of modern human origins?

Based on Figure 24.10, which of the following statements is TRUE?

All evidence suggests that the Neanderthals did not interbreed with our ancestors.

Interbreeding between Neanderthals and modern H. sapiens likely took place in _____ around _____ years ago, before H. sapiens spread around the world.

Many researchers hypothesize that modern humans have derived from the Homo ergaster populations that spread around the world starting about 2 million years ago. This hypothesis is known as the:

Approximately what percentage of non-African human nuclear DNA genomes are Neanderthal derived?

Approximately what percentage of modern human mtDNA is Neanderthal derived?

Genetic sequence data from mitochondrial and Y chromosome DNA agree that the human family is _____ and it arose _____.

Mitochondrial DNA studies were used to determine that Homo sapiens evolved in Africa and only later did they become established elsewhere.

If the out-of-Africa hypothesis of human origins is correct, which of the following BEST describes the pattern of hominin migration from Africa?

Why do we only see Neanderthal input in non-African genomes?

Which of the following properties of mitochondrial DNA (mtDNA) is NOT helpful in using mtDNA to infer the geographic origin and timing of the evolution of modern humans?

According to the multiregional hypothesis of human origins, modern H. sapiens evolved by _____ from _____ of H. ergaster.

According to genetic analyses, approximately _____% of the genome of every non-African is derived from Neanderthals.

Of the taxa listed below, which of the following nonmodern humans was the LAST to go extinct?

Which of the following statements is NOT correct regarding the multiregional and out-of-Africa hypotheses for the origin of modern humans?

Cro-Magnon is the name of the group of the first Neanderthals found in Europe.

Interbreeding between Neanderthals and modern H. sapiens likely took place in _ around _ years ago, before H. sapiens spread around the world.

Genetic sequence data from mitochondrial and Y chromosome DNA agree that the human family is _ and it arose _.

According to the multiregional hypothesis of human origins, modern H. sapiens evolved by _ from _ of H. ergaster.