Another newly described species has brought with it an evolutionary history that refuses to fit into creationism’s abbreviated chronology. This time it is a giant fungus from China’s Yunnan Province, named Dianjunus rex, whose family lineage is estimated to have diverged about 65 million years ago — almost 65 million years before the supposed ‘Creation Week’ of young-Earth creationism. Apparently, this fungus’s ancestors failed to wait for the universe to be created.
Described in a new paper in Frontiers in Fungal Biology, the fungus produces imposing reproductive structures reaching 50 centimetres high and weighing up to 2.2 kilograms. Its anatomy and genetic relationships justified the recognition of not merely a new species and genus, but a new family: Dianjunaceae.
The date needs a little care. The researchers are not claiming that today’s species has remained unchanged for 65 million years. Their evolutionary analysis estimates when its family lineage separated from its closest relatives, with a reported range of approximately 50–80 million years. That uncertainty is scientifically significant, but offers no refuge for biblical literalism: even the youngest end of the range is vastly older than the entire history permitted by a young-Earth reading of Genesis.
There is a further irony here. Genesis offers no recognition of fungi as a distinct group of organisms. Although biblical passages refer to conditions translated as mould or mildew, these are hardly an account of fungal biology or evolutionary relationships. We cannot know that the authors simply assumed mushrooms were plants, but we can say that their creation narrative supplies none of the distinctions needed to understand this discovery. That is unsurprising in an ancient religious text; it becomes a problem only when that text is presented as authoritative natural history.
The scientists, meanwhile, approached their discovery by comparing anatomy, analysing DNA and reconstructing evolutionary relationships. The result is a testable account of where this remarkable organism belongs in the history of life. Once again, evolution provides the framework that makes a discovery intelligible, while creationism is left with millions of years of history for which its preferred mythology has no room.
Fungi are not plants. Mushrooms may grow from the soil and remain rooted to one spot, but appearances can be misleading. Fungi belong to a kingdom of their own, separate from plants and animals. Indeed, evolutionary evidence shows that fungi are more closely related to animals than to plants: fungi and animals share a common ancestor more recently than either shares one with plants. This does not mean that fungi evolved from animals, or vice versa.The paper in Frontiers in Fungal Biology was accompanied by a news release on EurekAlert!:
A different way of obtaining food
Most plants use chlorophyll to capture sunlight and manufacture sugars from carbon dioxide and water through photosynthesis. Fungi lack chlorophyll and cannot photosynthesise. Instead, they obtain organic nutrients from their surroundings.
Many fungi release digestive enzymes into the material on which they grow, breaking complex substances into smaller molecules that they can absorb. In effect, they digest their food outside their bodies. Depending on the species, they may feed on dead material, exploit a living host, or exchange nutrients with a partner organism.
These are broad comparisons, not exception-free rules. Some plants have lost photosynthesis and obtain their carbon from other organisms. Nor does producing spores distinguish fungi from all plants: ferns and mosses produce spores too.
Feature Plants Fungi Nutrition Most manufacture sugars by photosynthesis. Absorb organic nutrients; do not photosynthesise. Cell walls Typically reinforced with cellulose. Usually contain chitin and glucans. Energy reserves Commonly store carbohydrates as starch. Store carbohydrates as glycogen, also used by animals. Body structure Land plants usually have organised tissues; many have roots, stems and leaves. Many consist of branching microscopic threads; yeasts grow mainly as single cells. Reproduction Varies widely; includes seeds in seed plants and spores in mosses and ferns. Often involves sexual or asexual spores; some reproduce by budding or fragmentation.
A mushroom is only part of the fungus
The familiar mushroom is a reproductive structure, rather than the whole organism. Much of a typical mushroom-producing fungus consists of fine threads called hyphae, collectively forming a mycelium. This network grows through soil, wood or other material, absorbing nutrients. The reproductive structures emerge when conditions favour spore production and dispersal.
Not all fungi produce mushrooms. The kingdom also includes yeasts, moulds, rusts, smuts, truffles and many other forms. Their diversity cannot be captured by the familiar image of a stalk topped with a cap.
Partners, recyclers and parasites
Fungi perform several fundamental ecological roles. Decomposers break down dead organic material, returning nutrients to circulation. Others form mycorrhizal associations with plant roots: the fungus typically receives carbon compounds from the plant while helping it acquire mineral nutrients and, in some circumstances, water. Still others are parasites or pathogens of plants, animals or other fungi.
Plants and fungi are therefore distinct evolutionary lineages whose lives are often closely intertwined. Recognising that distinction helps explain both their different biology and the partnerships on which many terrestrial ecosystems depend.
Scientists discover ‘D-rex’, a giant fungus from Chinese forests whose unique lineage dates back 65 million years
‘Fungal giant’ with one of the tallest fruiting bodies known represents new family which arose soon after extinction of the dinosaurs
Deep in the forests of Yunnan, China, scientists have discovered a ‘fungal giant’ that challenges our understanding of how large fungi can become. The newly described species, Dianjunus rex, produces vertical fruiting bodies up to 50 cm high and weighing up to 2.2 kg – the largest known within the phylum Ascomycota.
This remarkable species represents a new fungal family, Dianjunaceae, and provides a rare window into the evolution of extreme fungal body forms. The discovery illustrates how much fungus biodiversity remains to be discovered in East Asian forests.
Associate Professor Dr Indunil C Senanayake, co-author Germplasm Bank of Wild Species
Kunming Institute of Botany
Chinese Academy of Sciences
Kunming, Yunnan, China.
During fieldwork in temperate coniferous forests near Damaidi and Yipinglang and in tropical rainforest near Nanbang, scientists from the Kunming Institute of Botany found large whitish fruiting bodies (‘stromata’) clearly belonging to an unknown ascomycete fungus. These grew on woody roots of Chinese cork oak, emerging from the rhizosphere. Ascomycetes, with more than 64,000 species the largest group of fungi, don’t grow true mushrooms but instead release spores from tiny, sac-like structures inside or on the surface of such fruiting bodies.
The scientists collected the fruiting bodies and deposited voucher specimens in the collections of the Kunming Institute of Botany. They grew spores on media to study the morphology of the fungus, and also sequenced its genome, including the ensemble of protein-coding genes.
A king among fungi
Genetic results confirmed by a detailed study of its morphology revealed that the fungus represented a new species, a new genus and even a new family (Dianjunaceae) within the order Xylariales. The authors named it Dianjunus rex, for its regal size and the ancient Dian kingdom. The closest known relative to ‘D-rex’ is Graphostroma platystoma, which grows on dead hardwood across the northern hemisphere and by itself forms the family Graphostromataceae.
Xylariales are famous for their production of secondary compounds as well as enzymes which can degrade complex plant molecules. Such enzymes might likewise help ‘D-rex’ to digest dead wood.
Evolutionary origin shortly after dinosaur Armageddon
From a ‘molecular clock’ analysis of the new species’ DNA, while comparing it to the genome of hundreds of fungi with known evolutionary age, the authors were able to estimate that the Dianjunaceae arose around 65 million years ago. Strikingly, this is only one million years after the Cretaceous-Paleogene mass extinction event – famous for wiping out the dinosaurs besides countless other animals and plants.
This timing raises an intriguing possibility. After the mass extinction, forests experienced dramatic changes, including the sudden availability of large amounts of dead plant material. For wood-associated decomposing fungi, such environmental disruption may have created new ecological opportunities.
Associate Professor Dr Indunil C Senanayake.
Why does ‘D-rex’ grow so uncommonly big? Until now, the record-holders among ascomycete fruiting bodies measured 20 to 30 cm tall.
A fruiting body which towers above surrounding vegetation and debris could have better dispersal of spores by wind in dense forests. However, such a large structure requires substantial energy investment, suggesting that this strategy likely evolved only where the ecological benefits outweighed the costs.
Associate Professor Dr Indunil C Senanayake.
The researchers predicted that more discoveries of fungi from subtropical China lie in store.This region combines exceptional habitat heterogeneity, climatic stability, and complex biotic interactions that promote fungal diversification. Historically, however, fungal diversity in these ecosystems has been underestimated due to logistical difficulties in field sampling, the seasonal and cryptic nature of fungal fruiting, and a historical emphasis on economically important fungi.
Associate Professor Dr Indunil C Senanayake.
Publication:
For young-Earth creationism, the difficulty is straightforward: this newly recognised fungal family has an evolutionary history estimated to extend back some 65 million years. The uncertainty surrounding that estimate does not bring it remotely within the few thousand years allowed by a literalist reading of Genesis. Nor does the discovery of a previously undescribed species represent a recent act of creation. It represents a recent addition to human knowledge of a lineage that was already ancient long before humans existed.
Equally revealing is how the researchers established what they had found. Anatomy, DNA comparisons and evolutionary relationships supplied the evidence needed to recognise a new species, genus and family. The theory of evolution was integral to interpreting the discovery, providing a framework within which the organism’s similarities, differences and ancestry made sense. There was no explanatory gap that required an intelligent designer, and no indication that evolutionary biology had reached the limits of its usefulness.
The contrast with biblical literalism could hardly be clearer. Science can recognise that familiar appearances conceal unexpected relationships, revise classifications and uncover branches of life’s history that had escaped notice. An ancient creation narrative cannot acquire that explanatory power merely by being declared infallible. Dianjunus rex is another reminder that the natural world has a history of its own — one we discover by examining the evidence, not by requiring nature to conform to mythology.
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