African populations have been revealed to share Neanderthal ancestry for the first time, in findings that add a new twist to the tale of ancient humans and our closest known relatives.
Previously it was believed that only non-African populations carried Neanderthal genes due to interbreeding that took place after a major human migration out of Africa and across the globe about 60,000 years ago. The latest findings suggest human and Neanderthal lineages are more closely intertwined than once thought and point to far earlier interbreeding events, about 200,000 years ago.
“Our results show this history was much more interesting and there were many waves of dispersal out of Africa, some of which led to admixture between modern humans and Neanderthals that we see in the genomes of all living individuals today,” said Joshua Akey, an evolutionary biologist at Princeton University and senior author of the research.
The study suggests living Europeans and Asians carry about 1 percent Neanderthal DNA, compared with on average 0.3 percent for those of African ancestry. Akey and colleagues believe that this Neanderthal DNA arrived in Africa with ancient Europeans whose ancestors — over many generations — had left Africa, met and mated with Neanderthals and then returned to Africa and mixed with local populations.
“An important aspect of our study is that it highlights humans, and hominins, were moving in and out of Africa for hundreds of thousands of years and occasionally admixing,” said Akey. “These back-to-Africa migrations, largely from ancestors of contemporary Europeans, carried Neanderthal sequences with them, and through admixture, contributed to the Neanderthal ancestry we detect in African individuals today.”
The increasingly fine-grained details of our ancestors’ migration patterns and intimate encounters with other types of human are coming into focus thanks to the advent of sophisticated computational genetics techniques. These statistical methods allow scientists to line up the Neanderthal genome side by side with that of ancient modern humans and DNA from different living populations and figure out whether the different lineages have been steadily diverging or whether there are blips where large chunks of DNA were exchanged at certain time points.
The latest comparison highlights previously unnoticed ancient human genes in the Neanderthal genome, apparently acquired from interbreeding events dating to about 200,000 years ago. This suggests an early group of humans travelled from Africa to Europe or Asia, where they encountered Neanderthal populations and left a faint imprint on their genome that could still be detected more than 100,000 years later.
The paper also highlights the relative lack of genetics research in African populations, despite modern humans having first emerged on the continent and despite African populations today being more diverse genetically than the inhabitants of the rest of the world combined. “To more fully understand human genomic variation and human evolutionary history, it is imperative to comprehensively sample individuals from all regions of the world, and Africa remains one of the most understudied regions,” said Akey.
It is not known whether all African populations, some of whose roots stretch into the deep past, share this Neanderthal heritage. KhoeSan (bushmen) and Mbuti (central African pygmy) populations, for instance, appear to have split off from other groups more than 100,000 years ago. The findings are published in the journal Cell.
A: The Lantern Festival — the 15th day of the first lunar month — will be this Sunday. B: Where’s the Taiwan Lantern Festival being held this year? A: It’s taking place in Tainan and will run until March 10. B: It’s the Year of the Dragon: there must be a lot of dragon-shaped lanterns. How about the Taipei Lantern Festival? A: The event has moved back to Ximending and will run until March 3. A: 農曆1月15日元宵節，今年將會落在本週日。 B: 今年「台灣燈會」在哪裡？ A: 在台南，活動持續到3月10日。 B: 今年是龍年，應該會有許多以龍為造型的花燈。那「台北燈節」呢？ A: 這次燈節將會搬回西門町，活動持續到3月3日。 （By Eddy Chang, Taipei Times／台北時報張聖恩）
A: Tomorrow is the Lantern Festival. In addition to looking at lanterns, people also celebrate the day by eating glutinous rice balls. B: Although the fillings have become diverse in recent years, sesame- and peanut-flavored rice balls are the most popular. A: And every year, diehard fans of the two fillings always argue about which flavor is better. B: No wonder a company is selling sesame-peanut rice balls with two fillings, but they are a little pricey. A: Really? Then I have to try them. A: 明天是元宵節，大家除了要賞花燈還要吃湯圓。 B: 近年來湯圓的口味越來越多，不過最受歡迎的還是芝麻和花生湯圓。 A: 兩種口味各有擁護者，每年都引發一場湯圓大戰。 B: 所以有廠商推出了芝麻花生雙餡湯圓，不過也比較貴。 A: 真的嗎？我也想試試看。 （By Eddy Chang, Taipei Times／台北時報張聖恩）
According to legends, Cheng Cheng-kung (also known as Koxinga) is said to be associated with another Taiwanese food — milkfish. When Cheng was fighting the Dutch who were stationed at their fort named Fort Zeelandia, they lacked supplies and food, and couldn’t catch any fish to eat. As he worried about running out of food, one night, the sea goddess Matsu appeared in his dream and said, “Don’t say no fish. (Mo-shuo-mo-yu) There are fish in the sea near where your navy is at anchor.” 據說鄭成功還與另一道台灣美食有關—虱目魚。當鄭成功與堅守在熱蘭遮堡的荷蘭人交戰時，軍隊缺乏補給，無糧可食，也捕不到魚可吃。正當為食物發愁時，一天夜裡媽祖在他夢中指點：「莫說無魚。你的水師駐紮的海邊就有魚。」 station (v.) 駐紮 Fort Zeelandia (n.) 熱蘭遮堡，遺址位於現今的安平古堡內。 goddess (n.) 女神 The next day, Cheng
When people talk about eating as a communal activity, they generally refer to the feeling of friendship and togetherness that comes from sitting down and sharing a meal with others. Yet, there is another way in which eating can be seen as a group experience: eating contests. Competitive eating contests challenge a person’s eating speed or overall food consumption. Such events draw huge crowds and have become more and more popular with the streaming capabilities of the Internet. While no one knows for sure how long food competitions have been around, there is a 13th-century Norse myth that features an eating