An ancient, interdependent relationship that contributes to food systems and ecosystem stability across the globe could be changing.
Many flowering plants can self-pollinate (自花传粉), or transfer pollen between their own blossoms for seed generation and reproduction, but most of these plants have relied on pollinators such as butterflies and bees to reproduce. Now — during declines reported in many pollinator populations — a new study on the evolution of one flower species’ mating system has revealed a remarkable change that could worsen the challenges faced by the plants’ insect partners.
The flowers reproductive evolution may be linked to environmental changes such as habitat destruction and rapid ongoing decreases in pollinator biodiversity, according to Samson Acoca-Pidolle, who led the study published December 19 in the journal New Phytologist.
Comparing seeds of wild field pansies (三色堇) collected decades ago in France with the plants’ modern descendants. Acoca-Pidolle and his colleagues discovered that today’s flowers are smaller and produce less nectar (花蜜) as a result of increased self-pollination, which has direct impacts on pollinator behavior.The pansies of the past self-fertilized less and attracted far more pollinators than those of the present, according to the study.
“It seems that it’s only traits (特性) that are involved in plant-pollinator interaction that are evolving, ” said Acoca-Pidolle. The changes could restrict the plants’ ability to adapt to future environmental changes and have implications for “all of floral biodiversity” — potentially decreasing flowering plants’ genetic, species and ecosystem variation.
“This may increase the pollinator decline and cause a negative feedback cycle,” study coauthor Pierre-Olivier Cheptou told CNN.” If plants produce less nectar, there will be less food available to pollinators, which will in turn accelerate the rate at which the animals’ numbers decrease“, he explained.
“The major message is that we are currently seeing the evolutionary breakdown of plant pollinators in the wild,” said Cheptou, an evolutionary ecologist at the French National Centre for Scientific Research and professor at the University of Montpellier.
1. Which of the following may contribute to the flowers’ reproductive evolution?A.Changed behaviour of pollinators. | B.Severe pollution to the habitats. |
C.Continuing decline in pollinator biodiversity. | D.Increased plant-pollinator interaction. |
A.They self-pollinated less. | B.They had a better mating system. |
C.They attracted less pollinators. | D.They were fertilized by themselves. |
A.The flowering plants may have more variations. |
B.The evolution of wild plant pollinators is collapsing. |
C.The numbers of the animals will increase more rapidly. |
D.The plants will adapt to the environmental changes better. |
A.Pollinator Populations: Declining. | B.Flowering Plants: Selfing. |
C.Interdependent Relationship: Maintaining. | D.Floral Diversity: Increasing. |
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【推荐1】Modern agriculture and its ability to feed billions of people may be one of humanity’s greatest achievements. However, it comes with hidden costs. For example, have you ever considered how much water is needed to provide you with a steak or a salad? It may surprise you.
In a recent study published in the journal Nutrients, scientists from the Commonwealth Scientific and Industrial Research Organization (CSIRO), took a close look at the diets of 9,341 adult Australians – specifically, their “water-scarcity (缺少) footprints”.
The water-scarcity footprint is a widely recognized measurement of water consumption(消耗). First, it counts the liters of water you used. Then, it looks at the place where the water was used. Using a liter of water in the desert is not the same as using a liter of water in a tropical (热带的) rainforest. The more scarce water is in your area, the larger your water-scarcity footprint.
The scientists found that the average Australian’s diet had a water-scarcity footprint of 362 liters per day. Snacks and beverages – cookies, cakes, sodas and alcohol – accounted for 25 percent of the water-scarcity footprint. The research also included a glass of wine (41 liters), a single serving of potato chips (23 liters), and a small bar of milk chocolate (21 liters). Not surprisingly, cutting out snacks would be the NO.1 priority if you wanted to lower your own water-scarcity footprint.
Climate change is causing droughts and extreme weather. In 2018, Cape Town, South Africa, nearly ran out of water due to a drought. Its freshwater reservoir(水库) stayed at just above 13.5 percent of full capacity. By 2030, a world of about 8.6 billion people will need 35 percent more water, and 50 percent more food, according to the United States National Intelligence Council.
So, we need to watch what we eat, not just for our personal health but for the health of our societies.
1. What do we know about water-scarcity footprints?A.They are not related to places where we live. |
B.They measure how much water one consumes. |
C.They count the amount of water a family wastes. |
D.They are used to measure water scarcity in the desert. |
A.Stop eating snacks. | B.Go on a diet. |
C.Drink less sodas and alcohol. | D.Eat more cookies or cakes. |
A.To praise the efforts made by Cape Town. |
B.To explain the reasons for water shortages. |
C.To stress the serious situation in Cape Town. |
D.To show the harmful effects of climate change. |
A.It’s easy to feed all the people in the future. |
B.We are facing a greater shortage of water than of food. |
C.Water shortages may bring about many social problems. |
D.Our eating habits could make a difference to water shortages. |
【推荐2】How would you like an easy way to earn $2,500? All you have to do is to sit around and wait for your meals. There’s a catch, however. You have to stay in a chicken cage with a stranger for a whole week. There are no books or television or radio for a whole week. There are no books or television or radio for amusement. You can’t leave until the week is up. And a camera will be recording your every move.
Two people actually took the job. The idea came from Rob Thompson, a video artist. He wanted to make a film about the way animals are treated. His goal was to raise people’s awareness of the living conditions of animals that are raised for food. He decided to pay $5,000 out of his own savings to two people who were willing to live like chickens for a week.
To Rob’s surprise, quite a few people answered his advertisement. He had interviews and selected Eric, a 24-year-old restaurant worker, and Pam, a 27-year-old chemist. The plan was for them to spend seven days together in a chicken cage that was six feet long and three feet wide. A camera would record their experience, which would take place in an art museum.
The week was long and difficult. They slept on a hard wooden floor. They couldn’t stand up without banging their heads. They ate mash(a kind of food for animals) and drink water from a garden hose-pipe(软管). Their only privacy was a toilet surrounded by a curtain. There were no sinks, mirrors, or toothbrushes in the cage. Their only inspiration was the two framed checks that hung on the wall outside the cage. Visitors who came here were warned, “Do not feed the humans.”
Finally it was over, and Pam and Eric came out of the cage. They had survived the week, and they each had a $2,500 check in their hands. When Rob Thompson opened the cage, Eric came out, changed into clean clothes, and ate a chocolate bar right away. “It’s great for me to be able to stand up.” he said. Pam just changed her clothes and left. After a week of visitors and reporters watching her, she didn’t want to talk to anyone.
1. The underlined word “catch”(in Paragraph 1) probably means _______.A.unsolved problem | B.surprising wonder |
C.unbelievable condition | D.hidden difficulty |
A.That they had nothing for amusement. |
B.That they couldn’t lie down to sleep in the cage. |
C.That they didn’t have meat to eat. |
D.That they had to do almost everything in public. |
A.Make a film about humans and animals |
B.Advertise for his experiment about animals |
C.Show how terribly some animals are treated |
D.Experiment on how long a human can live in a cage |
A.An Easy Way to Earn $2,500 | B.Do Not Feed Humans |
C.Living Like a Chicken | D.Getting Along Well Anyway |
【推荐3】Ellen Kalish runs a center for rescued wild animals in New York. When a woman asked if she could treat an owl, she was happy to help. Then, the caller told her exactly where the tiny owl was hiding out. It was the Christmas tree in Rockefeller Center in New York City! Kalish said she has been helping wild animals for 20 years, but she has never heard a story like that. The rescued owl has been nicknamed “Rockefeller”.
When workers were unwrapping the tree which just arrived, one of them spotted the creature. It was buried in the base of the tree, Kalish said. At first the worker thought the owl might be injured. It would not let go of the tree’s base. One of the workers called his wife, telling her he was bringing the owl home. He asked if she could find a place that helps wildlife animals. She called Kalish.
The owl is the smallest of its kind living in the Northeast. So how did Rockefeller end up stuck in the tree in the first place? Kalish offered a few ideas. He could have gone to the tree to hide and got trapped later, she said. Maybe once the tree was loaded onto a truck, the branches squished (挤压) him into the trunk. He might have been too scared to move.
Kalish met the woman who first called her at a gas station. The woman handed her a cardboard box with the owl inside. “He looked up at me, and I was relieved to see that he was looking in relatively good shape,” Kalish said of their first meeting. She was impressed that he didn’t look worse.
Kalish brought Rockefeller back to the wildlife center. She said she gave him plenty of water and left two mice in the plastic pet carrier. They were gone by the next morning. Rockefeller spent most of his time at the wildlife center eating or sleeping. On Monday, he went to the vet (兽医) to get some X-rays taken. He has no broken bones, Kalish added.
Rockefeller will not spend much time at the center, she said. She is preparing to release him soon. He will fly away at dusk. That’s the time when owls normally wake up. The release will be quick and quiet, she said, and she will bring a camera to take pictures of him flying away.
“I will wish him a very long and happy life,” Kalish said. “For me, it’s the Christmas miracle of 2020.”
1. What can we learn about Ellen Kalish in Paragraph 1?A.She is a vet in a wildlife center. |
B.She is an employee in a nature reserve. |
C.She was surprised hearing the owl’s story. |
D.She had little experience in treating animals. |
A.It appeared suddenly as the tree was loaded onto a truck. |
B.It might have been too scared to move when trapped. |
C.It settled into the tree branches as home. |
D.It was locked into the trunk of a car. |
A.She rescued him from a damaged Christmas tree. |
B.She drove him back to his home in the Northeast. |
C.She gave him water and food at her wildlife center. |
D.She performed X-rays on the owl before releasing him. |
A.Unpleasant. | B.Comfortable. |
C.Stressful. | D.Disappointing. |
【推荐1】How to Celebrate Thanksgiving
Celebrated yearly on the fourth Thursday in November, the holiday of Thanksgiving was first observed (庆祝) in 1621 and continues to be an American tradition today.
(1) Make the table merry.
(2)
(3) Spend a little time thinking the meaning of Thanksgiving. Thanksgiving is a chance for many families to spend time together after being apart for much of the year.
(4)
A.Take a long nap after the meal if you’re feeling sleepy |
B.Consider helping the less fortunate during Thanksgiving |
C.Enjoy some traditional activities in Thanksgiving holiday |
D.It is a good time to think the love that you have for one another |
E.If you want to know how to celebrate Thanksgiving, just follow these steps |
F.Here are some things you’ll have to do to prepare the food for your holiday |
G.Arrange the table decorations the day before Thanksgiving if you have a separate dining table |
【推荐2】See the world and make a difference
Are you passionate about wildlife, earth science or the environment? If so, why not join a citizen science tour? These study trips allow you to participate in scientific research through observation and data collection.
Earthwatch
The environmental charity Earthwatch has been sending volunteers on research trips for nearly fifty years. The firm's latest tour takes citizen scientists to Peru on a weeklong journey to photograph, measure and collect genetic samples of fish to help stop overfishing.
Lindblad Expeditions-National Geographic
Lindbiad Expeditions-National Geographic was successful in launching last year's pilot program, Citizen Science BioBlitz. Trips starting this year will follow whales in Alaska, sharks in the South Pacific and study microplastics in the Antarctic.
Shinta Mani Wild
Shinta Mani Wild, a new tented camp in Cambodia's Cardamom Mountains, has partnered with the Cambodian government to safeguard an 800-acre river valley from poaching (偷猎) and mining “Our guests get real excitement from hopping on the back of a motorbike to save local wildlife, said Sangjay Choegyal, the general manager. NOTE: A minimum three-night stay is required and participants must be at least 13 years old.
Biosphere Expeditions
The international nonprofit Biosphere Expeditions has launched a series of new trips including monitoring the “Big Five” in Kenya. "Hard data forms the core of all scientific arguments, and we encourage people to collect useful data to help preserve the planet,said Matthias Hammer, executive director of Biosphere Expeditions.
1. Which of the following may best suit those concerned about oceanic pollution?A.Earthwatch. | B.Shinta Mani Wild. |
C.Biosphere Expeditions. | D.Lindblad Expeditions-National Geographic. |
A.It aims to stop overfishing. |
B.It welcomes young children. |
C.Its participants spend nights in the wild. |
D.Its participants get the chance to go hunting. |
A.The harm poaching has done to wildlife. |
B.The urgency of saving endangered animals. |
C.The role scientific argument play in education. |
D.The importance of data to environmental protection. |
【推荐3】Scientists have discovered a new behaviour among bumblebees that tricks plants into flowering early.
When lack of pollen, bumblebees will bite little by little on the leaves of flower-less plants. The damage seems to fool the plant into flowering, sometimes up to 30 days earlier than normal.
With their hairy appearance and special sounds, bumblebees are hard to miss in gardens all over the world. Their hairy bodies make them excellent pollinators for crops like tomatoes and blueberries. They are among the first bees to appear each year and work a long season.
But despite their key role, bumblebees, like many other pollinators have seen their numbers decline suddenly in recent decades. One recent study pointed to climate change, reporting that an increasing number of hot days in Europe and North America was raising local bumblebees extinction rates.
But researchers have now made a discovery about bumblebees that could have something to do with their long term survival. Scientists in Switzerland found that when the bumblebees were out of pollen, they started to bite on the leaves of plants that hadn't yet flowered. They used their mouths to cut clearly-shaped holes in the leaves. But the creatures didn't eat the material or use it in their nests.
The damaged plants responded by flowering earlier than normal- -in some cases up to 30 days ahead of schedule. Researchers also found that the bee damaged plants flowered 30 days earlier than undamaged plants and 25 days earlier than ones damaged by the scientists.
“I think everything that we've found is consistent with the idea that the bumblebees are damaging the plants and that that's an adaptation that brings flowers earlier and that benefits the bees,” said Dr Mark Mescher, one of the authors from ETH Zurich.
1. How do bumblebees fool plants into flowering earlier?A.By making use of the hot weather. | B.By putting the false flowers on the leaves. |
C.By attacking the leaves of flowerless plants. | D.By taking away the pollen from the other flowers. |
A.Making plants flower early. | B.Spreading pollen to flowers and plants. |
C.Sending information about weather change. | D.Finding out whether the plant has flowers. |
A.They are becoming homesick. | B.They are not as friendly as before. |
C.There is a sharp decrease in number. | D.They have been busy year by year. |
A.Uncaring. | B.Skeptical. | C.Tolerant. | D.Objective. |