搜索
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. |
同类型试题
y = sin x， x∈R， y∈[–1，1]，周期为2π，函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x， x∈[–1，1]， y∈[–π/2，π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x， x∈R， y∈[–1，1]，周期为2π，函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x， x∈[–1，1]， y∈[–π/2，π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
