Earth was bombarded by meteorites some 470 million years ago. Scientists initially thought that life on Earth began sometime during this event. Recent findings tell a somewhat different story. According to previous research life on Earth all but began during these meteor showers. Also, a large number of new species emerged at this time. Scientists named this event GOBE which is short for Great Ordovician Biodiversification Event. Initially, scientists made a connection between these two events. The theory was that the rocks that fell from the skies during the meteor showers started the evolutionary process in Earth’s seas.
What recent discoveries show is that sea creatures started flourishing during this period. The seas were filled with nautiloids, mollusks, trilobites, corals, plankton, and graptolites. The interesting thing about graptolites is that they are creatures that share the same skeleton and function like a prehistoric apartment building with shared walls. Rock layers all around the globe are filled with the remains of these creatures.
As a matter of fact, these layers are why scientists are sure that the meteorite showers and the GOBE are not connected. During excavations, the scientists found another layer filled with meteorite remains. It is because of these remains that the scientists from Lund University found in this layer that they can claim the rocks fell well after life started on Earth.
This was all possible due to the presence of zircon crystals. These crystals are helpful when determining the timeline of past events due to their ability to change over time. The elements found in these crystals have a tendency to change over time. These changes are almost always the same and are a great measure of time. And these exact changes allowed scientists to figure out when the crystals were formed.
The great thing about these crystals is that they tell us the whole story. They are a clear indicator of what went on during this time on Earth. The meteors did, in fact, fall to Earth some 470 million years ago. Some of the rocks fell into the sea and formed the seabed along with these zircon crystals. All this happened some two million years after the great explosion of life.
These findings do put a dent in the theories that the meteor showers started the evolutionary boom, but it is not difficult to understand where such an idea might come from. History has shown that a change in environmental conditions may speed up or alter the process of evolution. So, it is easy to understand why scientists thought something like this occurred.
This leaves many questions about the Great Ordovician Biodiversification Event unanswered.
The time at which this occurred there were many opportunities for new life to find a place under the Sun and thrive. Life was around for some 100 million years which is a really short time. Even extinction events are great opportunities for new life to evolve. A mini-extinction occurred around 510 million years ago. This then opened up an opportunity for new life to evolve during GOBE.
Additionally, during that time sea levels began to rise and that created large marine shelf areas where life had more space to thrive.
Alexandra grew up dreaming of being a great science explorer. She always wanted to travel the world and explore some of the greatest science mysteries of the times. After high school, she studied chemistry in college and spent most of her summers working on research projects alongside her professors. It was there that Alexandra got clarity about what she wanted to do in the future. She now works full time in science research at a teaching university and is planning to go to medical school in a few years. She likes to stay up-to-date with the latest discoveries in science and share her love for science through her writing.