According to the "News Hyperlink" of the Voice of China of the Central Radio and Television Corporation, Metasequoia, the only extant species of the Genus Metasequoia of the Fir family, was listed as a rare species of China's national first-class protected plants, and is known as a "living fossil" in the plant kingdom. This issue of Life Stories will focus on this ancient and precious plant.
Metasequoia is a deciduous tree with symmetrical growth of small twigs and leaves, drooping, preferring moist growth environments and strong adaptability. In the Mesozoic Cretaceous and Cenozoic, there were about 6 to 7 species in the metasequoia genus, but in the past it was thought to have long been extinct until it was rediscovered in Sichuan, China in 1941.
How was Metasequoia rediscovered? Why is it called a "living fossil"? Who else but Metasequoia is a "living fossil" plant? How is the distinction between high and low levels between organisms?
Metasequoia tree (Image source: Wuhan Botanical Garden)
How was Metasequoia rediscovered?
Metasequoia is the only species that discovers fossils first and living plants later. In the last century, Japanese botanists took the lead in discovering this plant in the fossil layer that was not seen by the scientific community at that time and named it. At that time, the scientific community generally believed that Metasequoia had been extinct on the earth for many years, and the time of extinction was even calculated in millions of years or tens of millions of years. Until 1941, the Chinese botanist Gan Duo first discovered a living Metasequoia tree in Modaoxi Town, Wanxian County, Sichuan Province (now part of Lichuan City, Hubei Province); in 1943, Wang Zhan officially collected Metasequoia specimens; in 1948, Hu Xianhua and Zheng Wanjun jointly published a paper and officially named Metasequoia. The story of Chinese scholars discovering Metasequoia also became a legend in the field of plant biology.
Metasequoia leaves (Image source: Wuhan Botanical Garden)
Ginkgo biloba, another plant "living fossil"
In addition to Metasequoia, China also has many "living fossil" plants, such as water pine, goosefoot catalpa, silver fir, ginkgo biloba, etc., of which ginkgo biloba is the most common and famous.
Ginkgo biloba, a rare tree species left over from the Mesozoic Era, is a specialty of China, originated 245 million years ago, and has survived after experiencing the turbulent changes of the global climate and environment during the geological and historical period and the interference of human historical activities, and has been widely cultivated.
Living Ginkgo biloba is the only survivor of the ancient Ginkgo family. Jiang Zikun, a senior engineer at the Chinese Academy of Geological Sciences, once compared the fossil layer of ginkgo biloba 200 million years ago with the living ginkgo biloba, and found that there was basically no difference in the "appearance" of the two eras of ginkgo biloba: there was a long stalk, the leaves were fan-shaped, the top edge had 2 lobes to multiple fissures and concave teeth, and the color was light green in spring and summer, and it became golden in autumn. In this regard, Shi Jun, a member of the Science Communication Working Committee of the Botanical Society of China and a popular science author, pointed out that "living fossil" plants such as ginkgo biloba may have special survival skills that have survived for hundreds of millions of years, and are very powerful species in order to cope with changes.
Left: Female leaves Right: Male leaves (Image source: Xi'an Botanical Garden)
Is the name "living fossil" of plants accurate?
Why call ancient, rare plant species "living fossils"? Shi Jun believes that the core reason is that these species have existed on the earth for a very long time, from ancient times to the present, to a large extent, the history of the entire earth's geological environment changes has been recorded. But Shi Jun also pointed out that "living fossils" is not a strict definition, "fossils are fossils, plants living on the earth, themselves are part of the ecosystem, the concept of 'living fossils' is not appropriate, not suitable for general use and promotion." ”
Who decides the high and low levels between the creatures?
Metasequoia and ginkgo biloba have responded to countless changes in the process of survival for hundreds of millions of years, and even "sent" dinosaurs and survived, are such species powerful? Who is the "king" of the earth compared to human beings? Who is more advanced?
Shi Jun pointed out that the high-level and low-level, complex and simple of species are actually an unusually relative concept. Humans often consider themselves to be the highest species, with trillions of cells, complex body makeup and the creation of human civilizations and multiple cultures. But compared to other creatures, the time of human appearance on Earth is actually very short, even if the ancestors of the genus of humans in the primates are included, the time of human appearance is only 6 million years. In contrast, other organisms, such as cyanobacteria in water, have existed for hundreds of millions or even billions of years, although they have only one cell, and can humans, known as "advanced, complex" species, really survive on Earth for that long? Who should decide the criteria for judging the high and low levels of biology? These are all questions worth thinking about.
Fossil specimen of ginkgo biloba about 160 million years old (Source: China Science Daily)
"Every life on Earth is a reasonable existence, and we should better learn how to live in harmony with them, learn and understand the history of the earth from different species and the survival wisdom that these beings have in these histories and apply it to the future development of mankind." Shi Jun said.
Producer: Bai Zhonghua
Reporter: Fu Zhao, Liu Fei
Editors: He Jia, Yang Yang, Peng Yuji