An ancient lake could hold the key to our understanding of how complex life evolved on Earth, according to research carried out by the University of Aberdeen. Scientists have studied samples of lake sediments deposited 1.5 billion years ago in the Bay of Stoer region in north-west Scotland, and discovered high levels of the metal molybdenum, a key element in the evolution of multicellular life, which challenges the commonly held view that an important stage of evolution, leading eventually to human life, occurred in the deep ocean, as opposed to a continental environment.
Professor John Parnell, from the University’s School of Geosciences, explains: “Molybdenum was required to support nitrogen fixation, which allowed simple life to flourish and support a food chain. It was also being incorporated into enzymes used by complex life.
“Previous research has measured the amount of molybdenum in rocks from ancient oceans to assess its supply, but found that it was only available sparsely at the time when complex life was expanding about 1.5 billion years ago.
“This new data, gathered from a site in north-west Scotland over the last year, shows that greater quantities of molybdenum were available in a continental environment at this time. This supports a growing theory that this important stage of evolution was advanced on the continents and not in the ocean.”
The site from which the sediments were recovered is already considered a highly-prized scientific resource, having provided evidence of how a critical point in evolution took place several hundred years earlier than scientists had previously understood. This latest discovery further underlines the importance of the site, whose geographic location makes it ideal for research purposes.
The Daily Galaxy via University of Aberdeen
Image at the top of the page is the nigmatic Horodyskia Putative oldest of the multicellular fossils. http://www.fossilmall.com/rare-fossils-10.htm