A recent discovery shows that bacteria have existed on Earth for 3.7 billion years ago, after 1 billion years since the Earth was formed.
In an effort to find the first animal life forms on Earth, scientists rely on fossils such as footprints, scratches, lair . of animals. Some scientists claim to have found animal evidence that existed more than a billion years ago, but these results are still controversial. In addition, there are some fossil tracks from the Ediacaran period showing that mollusks have proliferated and survived at this time.
Oceanographer Giulio Mariotti from Louisiana State University and his colleagues, found traces of life from Ediacaran's century and found that it could be bacteria . This result is published recently explained by credible evidence of the early life of the world.
A fossil shows traces of the species Dickinsonia Costa from Ediacaran century.(Photo: Wikipedia Commons).
Many bacterial fossils in Ediacaran era are found in topographical forms such as small ridges or craters, which are proof of bacterial existence in ancient times. The microbial carpet was proliferating in pre-Cambrian times - the time before the animal's diverse development, however, the microbial mat did not develop in the seas, when the latter herbivores would destroy the structure of them.
Mariotti and colleagues performed an experiment to create similar trails and trenches, holes in places where fossil tracks were found. They placed bacteria along the sand at the bottom of the water tank and created artificial waves on the water. The number of bacteria is larger than sand but less dense. Lower density allows them to move on sand with low energy consumption.
This fossil is made up of a trilobite.The trilobite moves from right to left and leaves a trail after passing through a land.(Photo: Stefano Novello).
The use of low energy levels is very important, because when using a lot of energy, they can lose the trace. The fossil tracks are mostly their paths, so when moving on the sand.
However, this study does not confirm those initial traces are caused by bacteria, but gives us a clear explanation of the traces left behind. If in the future, scientists find other fossil tracks from Ediacaran or earlier, we will have more accurate hypotheses about life during this period.
Fossils of bacterial species in the Ediacaran period (left) and vestiges are reconstructed from laboratory experiments by scientists (right).(Photo: SEPM).
We can distinguish the traces of different living species, based on their path relative to the source of food or enemies in a certain location. The traces left in Ediacaran century are complex three-dimensional sediments.
The formation and development of the first life forms on Earth are important to give us more understanding of life on other planets. We now need more concrete evidence of life at this time. Mariotti and his team are trying to find and perform more experiments to distinguish the fossils of different animals based on their traces.