Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Evidence of 600-million-year old fungi-algae symbiosis discovered in marine fossils


Is there an evolutionary relationship to land-based lichens?

Researchers from China and the United States have found evidence of lichen-like symbiosis in 600-million-year-old fossils from South China. The previous earliest evidence of lichen was 400 million years old, discovered in Scotland. The discovery also adds to the scarce fossil record of fungi and raises new questions about lichen evolution.

Xunlai Yuan, a paleontologist with the Nanjing Institute of Geology and Palaeontology; Shuhai Xiao, assistant professor of geosciences at Virginia Tech; and Thomas N. Taylor, professor of ecology and evolutionary biology at the University of Kansas, report their finding in the May 13 issue of Science ("Lichen-Like Symbiosis 600 Million Years Ago").

Yuan, Xiao, and their collaborators have been exploring the Doushantuo Formation in South China for a decade and have co-authored numerous reports of fossil discoveries, including algae and animal embryos. Taylor, a member of the National Academy of Sciences, is a paleobotanist who has reported on fossil lichens in Scotland.

Lichen is a consortium of two organisms that collaborate to survive in a harsh environment, such as exposed rock. One partner, a cyanobacterium or a photosynthetic alga, or both, are able to form food from carbon dioxide, while the other partner, a fungus, provides moisture, nutrients, and protection for the consortium.

"When and where did they first learn the tricks to form this collaboration?" Xiao asked. "The earliest lichen fossils described by Professor Taylor were from non-marine deposits about 400 million years old, when plants began to massively colonize the land. But did cyanobacteria or other algae form similar relationships with fungi in the marine environment, perhaps long before the evolution of land plants?"

Present-day examples of such relationships in the sea are abundant. Now, there is an example from ancient ocean life.

At a site where abundant algae lived in a shallow sub-tidal environment about 600 million years ago, Yuan and Xiao found three specimens that have evidence of two partners in a familiar relationship. "Enlargements of thin-section photomicrographs of the tiny specimens -- each of which was less than a millimeter in size -- show fossils of coccoidal or spherical cells surrounded by a net of fine filaments," Yuan said, describing the new fossils.

The scientists interpret the coccoidal cells as being sheathed cyanobacteria or possibly green algae. "The filaments have reproductive characteristics that make us think they are fungi," Xiao said.

Taylor said, "Clearly, there are two kinds of organisms living together and, we believe, interacting in more than a chance association."

In modern lichens and in the 400-million-year-old Scotland fossils, the coccoidal cells provide the nutrients and the fungal filaments provide protection against dehydration. But in the marine environment, dehydration is not an issue and the 600-million-year-old rocks also contain many fossils of coccoidal cells that are not surrounded by filaments. "So it is a loose lichen-like association," said Xiao. "The organisms are not obliged to live together."

Now there is a new question. "We know that this symbiotic relationship was forged 600 million years ago or earlier. But, was it carried over to land, or did each organism invade land and forge a new relationship independent of the marine relationship? If the latter, then the 600-million-year-old relationship may not be the direct ancestor of the 400-million-year-old relationship," Xiao said.

Fungi and algae in modern lichens can easily marry and divorce, he said. "Given the ease with which the symbiotic relationship is formed, I wouldn’t be surprised if the land-based relationships formed independently of the older marine relationships." "In fact, studies of modern lichens demonstrate that the lichen symbiosis evolved many times," Taylor said.

"The ability to form a symbiotic relationship between fungi and algae may have evolved long before the colonization of land by land-based lichens and green plants, which also form symbiotic relationships with various fungi," Xiao said.

"The Doushantuo Formation opens a window into ancient marine life. There is a lot more remains to be learned from these rocks," Yuan added.

Susan Trulove | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>