Professor Ross Large and his international team have discovered the reason behind a large gap in the evolution in life. There was a billion year time period where the advancement of life slowed to a crawl. His team found their answer embedded in seafloor rocks formed in ancient oceans. These rocks show a decline in Earths oxygen levels over this 'dead' period. Then, 550 million years ago, oxygen levels spiked and the Cambrian explosion of life began.
Nature of Science Themes
Science is collaborative - The team composed of scientists from Australia, Russia, UK, Canada, and Tasmania
Role of skepticism - Evolution is a highly debated topic around the world
This is a very interesting article. National Geographic did an article on the pre-cambrian era. These two articles are very intriguing as they give information about a time very few people know much about. The National Geographic article says more about how the oxygen levels started to rise. It states that as the number of bacteria rose, they started running out of chemical fuel, and eventually started carrying out photosynthesis. This caused oxygen to be released into the atmosphere, helping to kickstart life on Earth.
ReplyDeleteHere's the Nat. Geo. article: http://science.nationalgeographic.com/science/prehistoric-world/precambrian/
That is interesting how different amounts of oxygen can have such a big influence on the evolution of species. I wonder how the scientists discovered this gap in evolution because we have only known about evolution for about 200 years. I also think it would be very interesting to see where life would be today if this evolutionary gap never occurred. Natural selection is also a role in evolution. It would be interesting to see how the natural selection of different species was impacted by the reduced amount of oxygen.
ReplyDeletehttp://sciencenetlinks.com/lessons/the-history-of-evolutionary-theory/