Plants are stabbing, the answer to "tie hands" is actually in China

Author:Look at the think tank Time:2022.07.29

The "beautiful" of the plant world is often accompanied by "damage". Rose, succulent, cactus ... These assassin plants have maintained the relationship between animals and humans.

Why do plants grow? When is the earliest stabbing? How did it evolve? Scientists have always lacked in -depth research on these interesting issues.

Over the past few years, the ancient ecological research group of the Xishuangbanna Tropical Botanical Garden (hereinafter referred to as the Picna Botanical Garden) of the Chinese Academy of Sciences and the Chinese Academy of Sciences and the ancient Human Research Institute jointly formed a Qinghai -Tibet Plateau Plateau Antiques Anthropology Team, found a fossil plant group in the central part of the Qinghai -Tibet Plateau. It has the most well -known shape in the world.

The scientist's pumping cocoon finally found out the direct evidence of the history and cause of the evolution of the thorny plant. The results of this research have recently been published in "Nature -Communication".

Wen | Hu Yanqi Teng Wenyu

This article is reproduced from the WeChat public account "China Science Journal" (ID: China_sci). The original first published on July 27, 2022. The original title was "Why is the plant thorns? This "tie" answer is actually in China. "

Stone of the "Relaxing"

Beginning in 2016, the paleontological examination team has even conducted paleontological science investigations on the new generation of sedimentary basins in the Banong Lake -Nu River sewing band in the central part of the Qinghai -Tibet Plateau. A large amount of plant thorns.

There are 44 stones from the Lunpo Basin and the Nima Basin. According to the characteristics of shape, size, and growth methods, they are divided into leather and branches, with a total of 7 types. This is also the fossil plant group with the largest number of thorns worldwide in the world.

In North America and European fossils, there have been some thorns' records, and the number is not large, and scientists have not conducted in -depth research on them alone. Although the batch of thorns on the Qinghai -Tibet Plateau was taken to the laboratory of the Picna Botanical Garden, it was also "neglected" for nearly three years.

"Although these batch of thorns and fossils have different numbers and different forms, due to the lack of details, it is almost impossible to further determine these fossils into the species, or even subjects." Zhejiang Kun could not help but feel this feeling when they first saw them.

In 2019, these fossils were handed over to the hands of Zhang Xinwen, a doctoral student of the ancient ecological research group of the Penta Botanical Garden. In addition to the classification information description, how to trouble her can tell a new scientific story about thorns.

"Seeing the current stabbing plants, it is easy for us to think of their important environmental instructions in the ecosystem." Zhang Xinwen, the first author of the paper, told reporters.

She explained that thorns are a special organs of plants, which may come from specialized leaves, stems or epidermis. Because the surface area of the thorns is very small, it can reduce the steaming effect, thereby helping plants to adapt to some relatively dry environments. At the same time, thorns are also a defensive structure of plants, which can effectively reduce the frequency of eating foods. Therefore, the most typical living environment of assassination plants is tropical rare tree grassland.

"We have a full understanding of the current spiny plants. Ancient creatures are a discipline of ancient times, and we boldly speculate that the reason why the thorn appears is related to these environmental factors." Zhang Xinwen said Start research by ecological significance.

Why do bangs "outbreak"

So far, scientists have not found fossil records of the earliest thorny quilt plants, but according to the results of molecular system development analysis, they first appeared in the Late White Period. At that time, with the major outbreak of the quilt plants, the stabbing plants began to appear.

In this study, the research team combined with the analysis of the molecular system development, and rebuilt the cumulative curve of the new -generation Eurasia's taulted plant group. It was found that the stabbing plants began to differentiate from the beginning of the new generation. After the beginning of the new generation, the diversity of species showed multiple growth, which was in line with the geological age of the Tibetan Plateau's thorny fossils.

"This also confirms one of our thoughts -the types of stones found are very diverse, which means that the stabbing plants have been rapidly differentiated from the beginning of the New World." Zhang Xinwen said.

But what exactly caused the diversity of thorny plants at the time to increase rapidly? Is it related to the ecological environment?

In the same level, in addition to finding a large number of thorns, researchers also collected rich herbal plant fossils, totaling 315 copies, accounting for 38%of the number of all plant specimens at the same level. They also analyzed the micro -fossils of the same set of stratums layer by layer, and found a large number of silicon -implants produced by herbaceous plants, such as short -saddle -shaped silicon -type silicon -type silicon and precocious thyroid silicon implants And Zhiya's fan -shaped silicon. "These herbal plants want to thrive, which means that the environment at that time was an open habitat, not loses forest." Zhang Xinwen explained.

In order to further verify the guessing of this type of environment, the research team used the atmosphere of the University of Bristol in the United Kingdom to simulate the climate and ancient vegetation at that time, combined with the ancient environment of the fossil plant group. With the retreat of New Tyzy's in ancient times, the central valley of the central valley sutured in Bangong Lake -Nu River showed a tendency to drought. In addition, the global climate became cold, and the vegetation there was from the beginning of the new generation. The forest (about 47 million years ago) has transformed into a broad forest land, with tall trees, medium -altogenic shrubs, and low herbaceous plants. Interestingly, the researchers found that 658 animal fossils in the Qinghai -Tibet Plateau and its surrounding areas found that the diversity of large -scale implant mammals in the environment at that time began to increase.

"Due to the existence of open forest land, large -scale planting mammals enjoys richer food sources, which will inevitably lead to an increase in animal feeding pressure on plants, and then promote the evolution of the open forest plant thorns on the central valley of the Qinghai -Tibet Plateau." Zhang Xinwenwen It emphasizes that this is about 24 million years earlier than Africa.

"This research story illustrates the importance of fossils in understanding the evolution of plant functional traits." Zhang Xinwen said that research has proved the drought of the Central Qinghai -Tibet Plateau Central Valley and the feeding pressure of large -scale implant mammals. The rapid evolution of this functional character.

This also illustrates that the environmental changes in the Qinghai -Tibet Plateau in the geological history period not only have a profound impact on the diversity of plant diversity in Asia and even wider regions, but also shaped the functional traits of the region in the area.

Zhou Zhekun believes that the highlight of this study is also combining various methods and means such as large fossils, micro -fossils, system development analysis and model simulation. Learning and ecological cross -integration products.