Researchers have discovered microfossils resembling fungi in lavas that erupted on the seafloor 2.4 billion years ago, representing the oldest evidence of fungal life.<\/p>\n
The new paper, published in Nature Ecology and Evolution<\/em> today, suggests that fungi not only emerged much earlier than suspected but also evolved beneath the sea rather than on land.<\/p>\n Until now, the fossil evidence for cavity-dwelling fungi only extended back 46 million years, but the new discovery potentially extends that record by 2400 million years.<\/p>\n Professor Birger Rasmussen, from the WA School of Mines, Curtin University, said he found the microfossils during a routine microscopic study of the lava.<\/p>\n \u201cI was looking for minerals to date the age of the rock when my attention was drawn to a series of vesicles and when I increased the magnification of the microscope I was startled to find what appeared to be exquisitely preserved fossilised microbes,\u201d Professor Rasmussen said.<\/p>\n \u201cIt quickly became apparent that cavities within the volcanic rocks were once crawling with life.<\/p>\n \u201cThe new discovery has implications for the evolution of life on Earth, representing the earliest evidence of possible fungi by 1 to 2 billion years, and the earliest evidence of eukaryotic life by at least 500 million years.<\/p>\n \u201cWe hope this research will help to answer fundamental questions about the evolution of life on our planet and beyond.\u201d<\/p>\n The research aims to help identify targets in the search for life on rocky planets in the Solar System, including Mars, where vesicular basalts have been previously identified.<\/p>\n Co-author Dr Janet Muhling, also from Curtin University, said the team is currently searching the ancient volcanic rock record for microfossils to construct a more complete picture of life in the deep biosphere on early Earth.<\/p>\n \u201cThe discovery of well-preserved microfossils in 2.4 billion year-old vesicular basalts is exciting because it opens up the possibility that microfossils may exist in even older volcanic rocks than previously thought,\u201d Dr Muhling said.<\/p>\n The paper was co-authored by researchers from the Swedish Museum of Natural History in Stockholm.<\/p>\n