While life has established a firm grip on the dry surface of our planet, this was not always the case. Early in the history of life on Earth, life was only found in the oceans. Just how life moved from the oceans to land has captivated scientists for generations.
Researchers from the Nanjing Institute of Geology and Paleontology in China and Virginia Tech in the United States recently reported in Nature Ecology & Evolution their discovery of micro-fossils of green seaweeds that they say are 1 billion years old. Although only 2 mm in length, the tiny fossils have a big impact because they are the oldest green seaweeds ever found and land-based plants like trees and grasses all descend from these ancient seaweeds.
This discovery pushes back the age of green seaweeds and indicates that green seaweeds were producing the oxygen required by later land-based life earlier than had been thought.
Humans have long wondered what life was like early in our planet’s history. Fossil records can provide us with tantalizing clues, but it is humbling to be able to see a glimpse of the distant past in the detail that these fossils provide.
Coral reefs symbolize both the interconnectedness and delicacy of our environment. As researchers continue to identify new factors that can affect ecosystems, we must remain aware that even small-scale changes in our environment can have a wide impact.
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