Questions for ‘Globe’s non-Africans all descend from a single move out of Africa’

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All people across the globe inherited their DNA from people who evolved into Homo sapiens on a single continent. From there, descendants of those earliest humans spread out in waves to settle the rest of the world.

P.B. DEMENOCAL AND C. STRINGER/NATURE 2016

SCIENCE

Before Reading:

1. In what country were your parents born? And their parents? Trace back your family as far as you can and name all of the countries in your ancestry.

2. What do you know about the ultimate birthplace of all humanity? In which part of the world is it found?

During Reading:

1. The main premise of this story is that all people alive initially came from where? And roughly when did the ancestors of most people on the planet first leave there?

2. What type of evidence did three new teams of researchers use to come to this conclusion?

3. According to the story, about 2 percent of the DNA in modern-day Papuans came from bands of people who left Africa how long ago?

4. Eske Willerslev’s team offered data suggesting that the ancestors of people who today are Europeans and Asians initially spent thousands of years where (after leaving Africa)?

5. What was different about most of the initial trek of people who would become ancestors of people today in Australia and Papua New Guinea?

6. Axel Timmermann and Tobias Friedrich come to a different date than the other groups for the initial migrations from humanity’s homeland. What time period  do Timmermann and Friedrich propose for the migration, and what have they based it on?

7. What role would climate have played, if they are right?

8. Explain their argument for why the date of that initial migration might be obscured?

After Reading:

1. What is the major debate being described in this story and what role do genetics play in answering it? What role do climate data play?

2. The new studies cannot all agree on the timing for the initial long-range migrations of the earliest peoples. Does that mean one or more of the groups are wrong? Explain how you came to your assessment.

3. Explain how the new data might inform how we think of the “relatedness” or “unrelatedness” of different ethnic groups.

4. Sometimes scientists come to different conclusions using the same data — or related sets of data. Explain several reasons why that may be.

5. Often scientists need to reach conclusions from incomplete data. What data, if any, would make the arguments raised in this story more compelling?