Genomic studies have revealed a new branch of fungal evolution

A team led by the University of Alberta says about 600 distinctly different looking fungi have a common ancestor that never found a proper place
in the fungal family tree.
The team used genome sequencing to provide their own taxonomists
for these exotic organisms.

"They don't have any specific features that can be seen with the naked eye, so you can't say they belong to the same group
.
" But when you study the genome, all of a sudden, that's happening," said
Toby Spribille, the project's principal investigator and associate professor in the Department of Biological Sciences.

"I like to think of them as platypus and echidnas
in the fungal world.
"

Primbilly, chair of Canadian symbiosis research, was referring to Australia's famous monoporous animals that violate Linnaeus' classification system — they produce milk, have nipples, but lay eggs — a source of
debate about whether they actually exist.

"Although no one thinks our fungi are fake, they are similar because they look completely different
.
"

Using DNA-based dating techniques, the team discovered that the new fungus, called Lichinomycetes, originated 300 million years ago, a single source
240 million years before the dinosaurs went extinct.

David Díaz-Escandón, who conducted the study in his doctoral thesis, explains that these "eccentric" fungi were previously scattered across 7 different categories – among animals, a high-level classification, equivalent to the category
known as mammals or reptiles.

He worked with a team of researchers from 7 countries to extract material from fungi, sequenced 30 genomes, and found that all but one of the fungi came from the same origin
.

"They were classified, but they were classified into different parts of the fungal aspect of the tree of life, so much so that it was never suspected that they were related
to each other," says Díaz-Escandón.

These fungi include a variety of forms, such as the ground tongue (a weird tongue-like fungus that erupts vertically from the ground), beetle gut microbes, and a fungus
found in the sap of northern Alberta.
They also include some unusual lichens that survive in extreme habitats such as the Atacama Desert in South America, the driest non-polar desert
in the world.

"What's really fascinating is that even though these fungi look so different, they have a lot in common at the genomic level
," Splitbilly said.
"No one expected this
.
"

Based on their genomes, their genomes are small compared to other fungi, and the team predicts that the life of this group of fungi depends on other organisms
.

"Their small genome means that these fungi lose much of their ability to
integrate some complex carbohydrates," Splitbilly said.
"When we went back and looked at each fungus, all of a sudden we found that they were all in a symbiotic state
.
"

He noted that the new study will be important for broader research on fungal evolution, particularly how fungi inherit important biotechnology features, such as enzymes
that break down plant matter.

This new finding could also be a new source of
information about past fungal extinctions.

"We think the diversity we see today is likely just the tip
of the iceberg that has survived.
" We don't have so many examples
of this kind of thing in fungi.
”