（带文稿）0314V美华裔教授在我国这个城市发现了地球最古老植物化石【文末小测】

张老邪叨哔叨：

其实华人在生物科学领域一直都还是挺厉害的。比如基因编辑的创始人&麻省理工华人科学家张锋，还有之前提到过的普林斯顿大学教授及美国科学院院士颜宁（大）姐姐，获得联合国教科文组织杰出女科学家奖的张弥曼女士，还有北大的诺奖得主屠呦呦及其伯乐——北大终身教授饶毅。emmm 不过呢生物基本处在理工科就业市场鄙视链下游（经常被称为天坑专业），且因为生物时效性经常需要做实验到凌晨两三点（不然实验细胞就死啦），真的是清苦的学科~~

In this January 30, 2020 photo, Virginia Tech geobiology professor Shuhai Xiao, right, poses for a picture with his postdoctorate colleague Qing Tang inside Virginia Tech's Derring Hall. (Virginia Tech)

Transcript

        Scientists have discovered what may be the oldest fossils of a green plant ever found.

      The fossils were found in rocks from northern China. The plant is thought to be a piece of seaweed that grew on Earth’s seafloor about 1 billion years ago. That would make this seaweed an ancestor of all green plants alive today.

        Researchers in the United States reported on the discovery in the publication Nature Ecology & Evolution. The researchers are with the Virginia Polytechnic Institute and State University in Blacksburg, Virginia.

In the background of this digital recreation, ancient microscopic green seaweed is seen living in the ocean 1 billion years ago. In the foreground is the same seaweed in the process of being fossilized far later. (Photo Credit: by Dinghua Yang)

        The seaweed is a form of green algae called Proterocladus antiquus. It was very small, about the size of a single piece of rice. Researchers say the plant was connected to the seafloor with a root-like structure. At the time, the plant was one of the largest life forms in the sea, which contained mostly bacteria and other microorganisms.

     The researchers say Proterocladus was able to perform photosynthesis, taking energy from the sun to produce life-supporting carbon and oxygen. They believe the plant also provided food and shelter for many different kinds of sea life.

        Shuhai Xiao serves as a Professor of Geobiology at Virginia Tech. He said the fossils were found in rock taken from an area of dry land - formerly ocean - near the city of Dalian in China’s Liaoning Province. Qing Tang, another Virginia Tech researcher, discovered the micro-fossils in the rock using an electronic microscope in a laboratory.

        Xiao said the fossils represent the oldest green seaweed ever found. The next oldest fossil of green seaweed was found in rock thought to be about 800 million years old.

        The scientists say the seaweed once lived in an ocean that was not very deep. Once the plants died, they became “cooked” under thick sediment, which created fossils in the shape of the seaweed. Many millions of years later, the dirt was lifted out of the ocean and became the dry land where the examples were collected.

       “These new fossils suggest that green seaweeds were important players in the ocean long before their land-plant descendants moved and took control of dry land,” Xiao said.

        He added that Earth’s biosphere depends heavily on plants for food and oxygen. But the first land plants, believed to be ancestors of green seaweeds, did not appear until about 450 million years ago.

        The Virginia Tech researchers believe that land plants – including trees, grasses food crops and others – all developed from green seaweeds that lived in the ocean. Then, over millions of years, the seaweed plants moved out of the water and adapted to life on land.

In this April 9, 2016 photo, young sea lettuce grows on a rock in Mountain Point, Alaska. (Taylor Balkom/Ketchikan Daily News via AP)

        The history of how green plants developed is a subject of debate. “Some scientists think that green plants started in rivers and lakes, and then conquered the ocean and land later,” Xiao said.

        Proterocladus is believed to be closely related to a modern seaweed, widely eaten by humans today. It is called sea lettuce.

        I’m Bryan Lynn.

QUIZ【答案见下方词汇表后】

How does the article say the study relates to the present day?

A.The exact seaweed found in the fossils exists in many areas of the ocean today.

B.The seaweed in the fossils could be an ancestor of all green plants alive today.

C.The seaweed fossils are believed to have no relation to any green plants living today.

D.The discovered seaweed fossils only have living green plant ancestors in China.

How does the article describe photosynthesis?

A. When sunlight is used to produce oxygen from carbon

B. When oxygen is used to produce energy for ocean plants

C. When energy from the sun produces carbon and oxygen

D. When energy from the sun reaches plants on the seafloor

In what area was the rock found that contained the fossils?

A. On the seafloor

B. Under a lake

C. In a river

D. On dry land

How do some scientists disagree with from the theory of the Virginia Tech researchers?

A. The disagreeing scientists believe green plants started growing in the world’s oceans before moving to land.

B. The disagreeing scientists believe the seaweed discovered could not survive in an ocean environment.

C. The disagreeing scientists believe green plants started in rivers and lakes before moving to the ocean.

D. The disagreeing scientists believe the seaweed discovered was one of many green plants in the ocean.

Words in This Story

fossil – n. remains of an animal or plant from the past that are found in rock

algae – n. a simple plant that grows in or near water

sediment – n. a solid substance that forms a later at the bottom of a liquid

descendant – n. someone related to someone who lived a long time ago

biosphere – n. the part of the Earth’s environment where life exists

adapt – v. to change for a new purpose or use

conquer – v. to defeat or take control of something

【BCDC】