Researchers in Australia and the US are starting a multi-million dollar project to bring the Tasmanian tiger, nicknamed thylacine(袋狼), back from extinction. The last known one died in 1939.
The team say it can be recreated using stem cells(干细胞)and gene-editing(基因编辑)technology, and the first thylacine could be reintroduced to the wild in 10 years’ time. They plan to take stem cells from a living species with similar DNA, and then use gene-editing technology to ”bring back“ the extinct species - or an extremely close one of it.
It would be a great achievement for the researchers attempting it, and require a number of scientific breakthroughs.
The population of Tasmanian tigers dropped when humans arrived in Australia tens of thousands of years ago, and again when dingoes - a species of wild dog - appeared.Eventually, the species only lived free on the island of Tasmania, and was finally hunted to extinction.
If scientists were to succeed, it would mark the first “de-extinction“ event in history, but many outside experts doubt it, and believe that the project is more about media attention for the scientists and less about doing serious science.
The idea of bringing back the extinct has been around for more than 20 years. In 1999, the Australian Museum started to pursue a project to clone the Tasmanian tiger, and various attempts have been made ever since to get or rebuild DNA from samples. The US firm made headlines last year with its plans to use similar gene editing technology to bring the woolly mammoth back to life - a technological achievement yet to be made.
1.Which of the following might be the major reason for thylacine’s extinction?A.Habitat loss. | B.Climate change. |
C.Human activities. | D.Wild dog protection. |
A.It will make history. |
B.It is particularly difficult. |
C.It deserves greater attention. |
D.It is more of a piece of eye-catching news. |
A.Future for bringing back the extinct. |
B.Benefits of bringing back the extinct. |
C.Previous efforts to bring back the extinct. |
D.Technology needed to bring back the extinct. |
A.Science and Technology. | B.History and Traditions. |
C.Nature and Environment. | D.Culture and Society. |
We can shop alone, go to the gym, and-obviously-do all the daily activities like going to work alone.
People shared their lonely feelings on the Internet and listed the top 10 international lonely situations, such as having hotpot alone or undergoing an operation alone.
But actually, it depends on you.
In addition, when you start to enjoy being alone, you’ll come to find that you also enjoy your relationships with other people even more.
No matter how you feel about being alone, keeping yourself comfortable and happy is the most important thing in the world.
A.Some people don’t mind being alone. |
B.“Being alone” doesn’t mean you’re unwanted. |
C.Being alone gives you the perfect opportunity for self-reflection. |
D.However, maybe it is improper for people to do something special alone. |
E.It really sounds terrible because many people consider “being alone” bad. |
F.And that’s because the time spent alone gives you a greater appreciation for yourself. |
G.But for some reason, there are particular things people just find too strange to do alone. |
Green Thumb
All I did was show my little sister how to grow plants. Dig a hole. Put in a seed. Cover it with dirt. Water it. Wait. “See, Laynie,” I explained, “a whole plant will grow from this tiny seed. All we have to do is water it.”
Laynie had her own watering can so she could “help” me in the garden. One day, after everything was watered, she ran to the fence and started sprinkling water on another spot. I walked over and saw a fresh patch of dirt near the fence.
“Did you plant something there?” I asked.
“Yes,” she said. “I’m growing a pencil. My purple pencil got too small, so I planted it.”
“What? But, Laynie—”
I should have explained things right then, but I just muttered, “Uh…I never grew one before.”
Later I got what seemed like a great idea. I dug up Laynie’s pencil and “planted” a brand-new purple pencil. Laynie was really excited when she saw it. “My pencil grew!” she shouted.
A few days later, Laynie was watering on the same spot. Two days later, new crayons sticking their pointy little heads out, thanks to me. Laynie jumped up and down and yelled, “They look like flowers!” She “picked” them and ran into the house.
Next, Laynie grew an adult bear doll from a tiny one, a soup spoon from a teaspoon, and a hand mirror from a piece of glass. When she claimed that she had grown these things, I just kept my mouth shut! Actually, it was fun trying to think of what should grow from Laynie’s seeds. And it was cool to see her get excited.
One day I saw her patting down some dirt near the fence again, so I knew she’d just planted something. My heart dropped to my feet when she asked, “How long does it take to grow a goldfish, Brad?” I couldn’t speak.
“Not long, I bet!” said Laynie. She knelt down to whisper “Grow, Molly. Grow!” before she skipped back to the house.
I sat down with my back to the fence and thought for a long time.
Later I found Laynie sitting by the spot where Molly was buried.