Fossils of the genus Phyllica formed about 100 million years ago; the extant genus Phylidae is extant. Courtesy of Wang Shuo
This is no ordinary flower, it has survived on Earth for about 100 million years, during which time its appearance has not changed.
The main discoverers of this flower are Wang Shuo and Shi Chao, a "post-85" couple professor at Qingdao University of Science and Technology, who have a common research object - amber fossils from 100 million years ago. Recently, Nature Plants reported on the couple's latest research in the form of a cover paper, and they found the oldest intact flower in amber fossils, and found the flower in the Cape region of South Africa 100 million years later.
The face has not changed: from fossil to real flower
Where did the flowers (angiosperms) on Earth come from 100 million years ago? Academics have been arguing about this topic for about 160 years, and there is no solution.
Fossils provide the best answers. In general, the information preserved by plant fossils is limited to some organs. Researchers' studies of the early, mid-to-late Cretaceous period have found few complete fossil angiosperm flowers, and if they have, most of them have been extinct.
Eight years ago, Wang Shuo and Shi Chao joined an international research team to conduct phylogenetic analysis of the surface subtle morphological characteristics and internal three-dimensional structure of 21 amber fossils, and found multi-organ solid fossils such as branches, flowers, fruits, leaves, pollen and other well-preserved branches 100 million years ago, and restored the whole process of growth and development of this plant from infancy to maturity.
Why did this study take 8 years? The researchers initially studied more than 40 amber fossils, but some of them were not well preserved enough to get a clear three-dimensional structure when doing CT scans, and finally identified 21 amber fossil pattern specimens.
In addition, researchers have also taken some detours in the fossil identification process. Previously, these fossils had been misidentified as gymnosperms and algae. Later, the researchers compared the fossils contained in amber with their possible descendants, ruling out the possibility of convergent evolution between different plant groups.
Another unexpected discovery was that the researchers found an extant taxon of plants in the Cape Botanical Region of South Africa that were almost identical to the morphological characteristics of plants in the amber fossils.
Wang Shuo introduced that this taxon comes from the genus Phyllica in the family Phylica, which is an endangered plant that grows in the Cape region. "The genus probably lived and bred in the Cape botanical region of South Africa for about 100 million years, starting with the Mesozoic Era when dinosaurs flourished and has been blooming ever since."
Gymnosperms that originated before the Cenozoic Era, such as ginkgo biloba and Metasequoia, are called "living fossils" by the academic community. "Phylica, 100 million years ago, has hardly changed morphologically, and we have reason to call it a living fossil of angiosperms." Wang Shuo said.
Wildfire Survival: From Ancient times to Modern Times
Meet again in 100 million years, still the flower.
Most of the extant species of Phylica are specifically distributed in the Cape botanical region at the southern tip of Africa, while the amber fossils used in the study were found in northern Myanmar. The two are located on different continental plates.
This phenomenon has attracted great attention from researchers. Further research found that the flora of northern Myanmar is linked to the southernmost flora of the African continent, which is related to the "vicissitudes" caused by plate movements over the past hundreds of millions of years.
Wang Shuo explained that these fossil plants, which are well preserved in amber, formed before the Indian Plate and the Gondwana Paleo-Continental Zone were completely separated, and with the disintegration of the Gondwana Paleolust and the northward shift of the Indian Plate, the ancestors of this biota spread to northern Myanmar through the Indian Plate, but their descendants have been living and reproducing in the Cape Flora of South Africa.
During these 100 million years, the Earth has undergone tremendous changes, climate changes, plate drift, land and sea changes, and the Cretaceous-Tertiary mass extinction (about 65 million years ago), the dinosaurs disappeared, and Phylica's other sister groups gradually became extinct.
In contrast, during the middle Cretaceous period (about 100 million years ago), angiosperms evolved rapidly, a phenomenon and its causes that have been a hot topic for biologists — including Darwin, who once called it "an annoying mystery."
In response to this problem, the international research team has proposed an idea: frequent fires in the middle of the Cretaceous period may be an important driving force for the evolution of angiosperms.
Wildfires play an important role in the adaptation of sclerophyll shrubs and succulents to arid and hot environments in the Cape Botanical Region of South Africa. Studies have found that many plants distributed in the Cape region to date are fire-adaptable.
Similarly, the plant fossils found in the study also showed a high degree of adaptability to frequent wildfires, such as slender and tightly packed leaves, flowers tightly wrapped by leaves, and dense surfaces.
Among these amber fossils, the researchers also found a large number of plant remains suspected of having been burned by fire, which also corroborated the frequent fires that occurred in the middle of the Cretaceous Period. These indications suggest that the strong adaptability of angiosperms to the environment may be a reason for their rapid radiation evolution.
Who would have thought that behind the blossoming of wealth there is a history of survival in adversity. The descendants of Phyllica, who have experienced the baptism of time, have survived and multiplied in the southernmost part of Africa to this day, and have become an important taxon of the Fynbos (sclerophyllous shrubs and slurred vegetation endemic to the Cape Botanical Region) in the Cape Botanical Region of South Africa today.
Submission Storm: From Rejection to Cover
It is understood that the weight of the research results is enough to appear in journals such as Science and Nature, but it has been rejected in the process of submission. The reason is that some scientific research groups led by the Vertebrate Society of North America (SVP) have joined forces with numerous international journals to question the ethical problems of mainland researchers' research on amber fossils in northern Myanmar.
Amber is formed by the underground burial and mineralization of resins secreted by plants such as conifers for tens of millions of years to 100 million years, and is a precious fossil resource that is second to none in the study of biological origin and evolution.
Blood Perth is one of the best. Also known as blood amber, red amber, red or crimson in color, it is mainly produced in northern Myanmar, formed in the Cretaceous Period about 110 million years ago to 99 million years ago, and is one of the oldest ambers in the world. Ordinary amber is mostly pale yellow to dark brown, and the reason why blood is red is because the oxidation that occurs on the surface of amber spreads into the interior of amber over time, forming a "red as blood" blood perlation.
In addition to Myanmar, Mexico, the Dominican Republic, the Baltic Sea and other regions also produce very small amounts of blood persper. However, the natural blood perch color is gray and dark and has more impurities, so the pure and beautiful blood perk on the market is artificially roasted and changed color.
As an important variety of amber, blood permea not only has a high market value, but also has its significance in scientific research. Mainland researchers have achieved a series of results in this research object, such as the discovery of important biological groups such as extinct insects, plants and even dinosaurs for the first time.
However, the SVP maliciously misinterpreted the meaning of the word "blood" to describe the color, imposed the stigma of "dyeing the blood of the workers" on "blood amber", and jointly blocked the relevant research papers of mainland researchers in a number of journals, making the mainland once difficult in the field of amber fossil research, and also hitting the wall everywhere.
In order to protest the stigmatization of mainland amber fossil research by foreign groups, researchers from Qingdao University of Science and Technology, Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences, Institute of Botany of the Chinese Academy of Sciences, Institute of Zoology of the Chinese Academy of Sciences, Kunming Institute of Botany of the Chinese Academy of Sciences, South China Botanical Garden of the Chinese Academy of Sciences, China Agricultural University, Minzu University of China, Shandong Normal University, Shanghai World Expo Museum, Open University of the United Kingdom, university of Kansas and other institutions jointly published "Balancing Scientific and Ethical Concerns: Perspective" in Nature-Ecology and Evolution The Subtle Perspective of "Blood Amber"" article.
This article not only reveals the real formation process of "blood amber", but also clarifies the position of mainland scientists, hoping that relevant international groups, especially scientific groups, can face up to this problem, do not continue to denigrate China's amber fossil scientific research work, and promote the normal development of amber fossil research.
Eventually, the latest research was on the cover of Nature-Plants. (Reporter Shen Chunlei)
Related paper information:
https://doi.org/10.1038/s41477-021-01091-w
Source: China Science Daily