A fossil that is said to be "the oldest activity trace of the world" of 3.7 billion years ago is discovered

The largest island in the world belonging to the Arctic Circle ·GreenlandFrom the rocks, I found that fossils that are also seen as traces of life 3.7 billion years ago were discovered. If this fossil is due to a real creature, it will be two hundred million years older than the traces of life that have been discovered so far.

Scientists find 3.7 billion-year-old fossil, oldest yet
http://phys.org/news/2016-08-scientists-billion-year-old-fossil-oldest.html

New find might be oldest evidence of life on Earth | Ars Technica
http://arstechnica.com/science/2016/08/new-find-might-be-oldest-evidence-of-life-on-earth/

Greenland is an island whose majority of the area is covered with snow and ice. However, snow and ice which covered the land due to global warming in recent years has melted, and the place where the ground is exposed is increasing. The fossil of this time has been found from such a place where we could not observe in the past.

The fossils were discovered in the School of Earth & Environmental Sciences (University of Wolongong), Australia's School of Environmental SciencesAllen NutmanIt is a research team by professors. The research team has found a fossil of a structure that seems to have formed microorganisms that lived in shallow beaches on an ancient earth from among the rocks of the area called Isua in the western part of Greenland. The research results of this team will be published in the scientific journal "Science".


Here are the pictures of fossil patterns seen by Professor Nutman and others. It is clear that a heterogeneous pattern is clearly left in the layered pattern due to sediment deposited in the shallow. According to the research team, this rock is formed by the dead bodies of microorganisms such as algae and mudStromatoliteIt is believed that it was created by life activities about 3.7 billion years ago from now. Furthermore, considering the long years before fossils are formed, it is thought that microorganisms that created stromatolite existed more than 100 million years ago before 3.8 billion years ago.


Speaking of 3.7 billion years ago, "only" 700 million years have passed since 4.5 billion years ago when the earth was born. It is a time when the lava dissolved in the muddle solidified and the sea was already formed, but the sea at that time was green because it contains a lot of iron, and furthermore, oxygen that makes the sky blue is not present in the atmosphere , The sky at that time is thought to have been seen as orange.

Traces of life found so far were fossils of 3. 348 million years ago, but if this fossil is actually caused by microorganisms, the history will be traced back to 220 million years further . Professor Martin Van Kranendonk of the University of New South Wales who is a coauthor of the thesis and an officer at the Australian Space Biology Center stated, "This fossil shows how our planet evolves and how life is progressing I will tell you if I got it. "

In Isua, Greenland, the research team of Tohoku University et al. Discovered substances that are believed to be traces of life 3.8 billion years ago in 2013 as well. What was found at that time is carbon (graphite) that supports the existence of living things, having the same carbon isotope composition (12 C / 13 C ratio) as that of the life of this world, characteristic of the carbon constituting this living organism It was concluded that it was a piece of microorganisms that had lived in the sea 3.8 billion years ago because of the appearance of nano-level tissues and contours appearing in the sea.

Tohoku University Graduate School of Science and Science · Faculty of Science
http://www.sci.tohoku.ac.jp/news/20131209-2632.html

Creatures of 3.8 billion years ago, traces in Greenland Tohoku University etc: Nihon Keizai Shimbun
http://www.nikkei.com/article/DGXNASDG0901Z_Z01C13A2CR0000/

On the other hand, it is also a fact that there is still much room for discussion in this research result. Originally, the occurrence of stromatolite is commonly seen in a wide range, but since the scale found this time is small, there are many researchers who will not break the view that future further verification is indispensable . Sometime I was involved in research on Australia's stromatolite, the Paris Institute of Earth PhysicsPascal Philippot"I do not want to be too skeptical, but it will be clear that new evidence will be discovered in the coming months and years, which is not a misunderstanding," We are posting comments that hope to find evidence.

Also, it is also a fact that there is a view that the pattern found this time is due to the work of the crust. In order to prove that fossils, which are considered to be "traces of life" found this time, are likely to require more time and physical evidence still.