A study says the origin (起源) of humans is in Bostwana. Researchers said they used DNA to find out where modern humans came from. They believe all our roots are in a region (地区) of northern Bostswana. Humans were there 200,000 years ago. They lived there for at least 70,000 years and then migrated around the African continent. They then started moving to Europe and Asia. Researcher Professor Vanessa Hayes, from the University of Sydney, said, “We’ve known for a long time that modern humans originated in Africa about 200,000 years ago.”

The researchers made sure of an area called Okavango as where we came from. There used to be a big lake but it is now salt flats. People had water, hunting and farmland. Scientists studied DNA from 200 people who live near the area today. They are from the Khoisan people, who live in modern-day South Africa and Namibia. They had a lot of DNA called L0. Professor Hayes explained why L0 is important. She said, “Every time a new migration happens, that migration event is recorded in our L0 and DNA as a time-stamp... Everyone walking around today comes from this region.”

During the COVID-19 pandemic, many people under lockdown feel lonely and bored. “There is a loneliness epidemic,” said John Dattilo from Pennsylvania State University, US.

So he, together with an international team of researchers, studied how to reduce loneliness and increase positive feelings during the pandemic.

According to their new study, reduced loneliness has something to do with doing enjoyable activities that require both concentration (注意力) and skill.

“When people are absorbed in (全神贯注于) what they are doing, they enter a state (状态) called ‘flow’.” Dattilo explained. “Flow can be achieved by doing activities that we value and that require us to concentrate fully to use our skills.”

To achieve a state of flow, there must be a balance between the challenge of the task and your skill level. For example, if you’re trying to create a complex (复杂的) computer program but your skill level is low, then you’re likely to feel stressed instead of achieving “flow”. On the contrary (相反地), if the task is too easy, then boredom will set in and “flow” will not appear, either.

If you have artistic skills, for example, playing the piano or painting can lead to flow. So can things like skiing, writing and storytelling, depending on who you are.

“When we enter a state of flow, we become absorbed and focused, and we experience momentary (片刻的) enjoyment,” Dattilo said. “When we leave a state of flow, we are often surprised by how much time has passed.”

However, watching television usually doesn’t help people enter flow, according to Dattilo, because there aren’t any challenges.

“People tend to thrive (茁壮成长) on healthy activities and challenge,” said Dattilo. “We hope this research will help people live fuller, happier, healthier lives.”

Do you walk slowly? If so, you may not want to hear the findings of this study.

Scientists at Duke University found that the slower a person walks, the less（较少的）capable his or her brain is.

Scientists studied the walking speeds（速度）of 904 middle—aged people from New Zealand starting from when they were just 3 years old. Over 42 years, scientists tested their walking speed many times.

They found that the speed had something to do with the brain. If the subjects （实验对象）had lower IQ scores and worse language skills as children, they were likely to become slow walkers as they reached middle age. At the age of 45, the average gap in IQ between the slowest and the fastest walkers was 16 points.

Scientists said that genes （基因） might be the reason for this. However, smarter people may be more likely to do physical activity, which means they may walk faster later in life.

Can slower walkers make their brains work better? Maybe. Scientists looked at the brain scans of 926 people. They asked them to walk as fast as they can for two minutes. Scientists checked the distance they walked and then asked them to take some tests. Those who walked further and faster did better on the tests.