1 . In 1879, an 8-year-old girl made a discovery that would rock our understanding of human history. On the walls of Altamira cave in northern Spain, she spotted amazing drawings of wild cows, painted in vivid red and black. More striking even than the images was their age: they were made thousands of years ago by modern humans’ supposedly primitive ancestors. Today, nearly 400 caves across Europe have been found decorated with hand stencils (模板), strange symbols and beautiful images of animals created by these skillful artists.
The discoveries led to the view that artistic talent arose after modern humans arrived in the region some 40,000 years ago, as part of a “cultural explosion” reflecting a flowering of the human mind. But more recent evidence has blown this idea out of the water. For a start, modern humans might not have been the first artists in Europe. What’s more, a collection of cave paintings emerging in Indonesia has dismissed the idea that Europe was the centre of creativity.
Local people have long known that the caves of the island of Sulawesi, Indonesia, contain many painted images. Modern humans are thought to have reached the region some 65,000 years ago, but nobody imagined the art could be very old because ancient paintings seem unlikely to survive in the environment of high temperatures. A team of researchers led by Maxime Aubert, now at Griffith University in Australia, upended this idea using a technique that is shifting our understanding of cave art. Using this technique in seven caves, they found a hand stencil was at least 39,900 years old, making it the oldest known hand stencil at that time.
This opened a floodgate to new discoveries in Indonesia. These included a hunting scene created at least 43,900 years ago, and by far the oldest descriptive artwork. “When we found that image, we were absolutely delighted, but when it turned out to be that old, we were almost jumping with joy,” says Adam Brumm, also at Griffith University.
1. What did the girl find in the cave?| A．Wild animals. | B．Ancient images. |
| C．Painting techniques. | D．Recording artists. |
| A．It can be traced back to Europe. |
| B．It reflected the flowering of human minds. |
| C．Modern humans led to its rise in Indonesia. |
| D．Modern humans might not have been real artists. |
| A．Proved. | B．Strengthened. | C．Overturned. | D．Overemphasized. |
| A．The amazing discoveries. | B．The researchers’ expectations. |
| C．The benefits of the technique. | D．The description of the cave art. |
2 . While DNA from animal bones or teeth can cast light on an individual species, environmental DNA enabled scientists to build a picture of a whole ecosystem.
A core of ice age sediment (沉积物) from northern Greenland has yielded the world’s oldest sequences of DNA. The 2 million-year-old DNA samples revealed the now largely lifeless polar region was once home to rich plant and animal life — including elephant-like mammals known as mastodons (乳齿象), reindeer, hares, lemmings, geese, birch trees and poplars, according to new research published in the journal Nature on Wednesday.
The finding is the work of scientists in Denmark who were able to detect and restore environmental DNA — genetic material drop into the environment by all living organisms — in tiny amounts of sediment taken from the Copenhagen Formation, in the mouth of a strait in the Arctic Ocean in Greenland’s northernmost point, during a 2006 expedition.
They then compared the DNA pieces with libraries of DNA collected from both extinct and living animals, plants and microorganisms. The genetic material revealed dozens of other plants and creatures that had not been previously detected at the site based on what’s known from fossils and pollen records.
“The first thing that blew our mind when we’re looking at this data is obviously this mastodon and the presence of it that far north, which is quite far north of what we knew as its natural range,” said study co-author Mikkel Pedersen.
The mix of temperate (温带) and Arctic trees and animals suggested a previously unknown type of ecosystem that has no modern equivalent — one that could act as a genetic road map for how different species might adapt to a warmer climate, the researchers found.
Love Dalen, a professor at the Centre for Palaeogenetics at Stockholm University, said the finding “pushed the envelope” for the field of ancient DNA. “Also, the findings that several temperate species (such as relatives of spruce and mastodon) lived at such high latitudes are exceptionally interesting,” he added.
Further study of environmental DNA from this time period could help scientists understand how various organisms might adapt to climate change. “It’s a climate that we expect to face on Earth due to global warming and it gives us some idea of how nature will respond to increasing temperatures,” he explained.
1. What can we know about environmental DNA from the passage?| A．It makes it easier to understand individual species. |
| B．It is a collection of DNA from all kinds of living things. |
| C．It includes DNA of mammals living 2 million years ago. |
| D．It was first discovered in sediment from northern Greenland. |
| A．By looking at the data of mastodon. |
| B．By detecting DNA samples at the site. |
| C．By analyzing fossils and pollen records. |
| D．By comparing the newly-found DNA with existing ones. |
| A．broke the limit | B．laid a foundation |
| C．raised a new question | D．attracted wide attention |
| A．Northern Greenland faces species extinction |
| B．Oldest DNA reveals a solution to global warming |
| C．Northern Greenland faces increasing temperatures |
| D．Oldest DNA reveals a 2 million-year-old ecosystem |
