The father of the science of evolution, Charles Darwin, hypothesized that life on Earth began in "warm little ponds," shallow pools of water where the biomolecules necessary for life underwent a series of chemical reactions that led to life.
There's only one problem with this theory, in the time frame that Darwin hypothesized that these pools existed, Earth itself was one giant pool. The entire planet was a "water world," covered by deep oceans, and the continents had yet to poke their heads above the water. No ground, no shallow pools.
A new study found in the January 4, 2021 online edition of the journal Nature Geoscience proposes a solution to this conundrum. Researchers Juan Carlos Rosas of the Ensenada Center for Scientific Research and Higher Education in Mexico and Jun Korenaga, a professor of earth and planetary sciences at Yale University, created a theoretical model for Earth's seafloor during the Archean eon, which is between 4,000 million and 2,500 million years ago.
Rosas and Korenaga found that back then, Earth's core was providing much more heat to the mantle, or crust, than it does today. This heating could have created shallow ocean basins in some parts of the world that would have led to volcanic islands and ocean plateaus forming that would have remained for hundreds of millions of years.
According to Rosas and Korenaga, what was causing the heating of the mantle was the decay of radioactive elements, such as uranium, in Earth's crust. Radioactive elements disappear over time, so there must have been more of them at that time.
Over the last 150 years, many new islands have been formed by volcanism, but only three have survived for a significant period of time, and each has nurtured an abundance of life.
Surtsey - Iceland
In the Atlantic Ocean south of Iceland sits the new island of Surtsey. It was formed by a volcanic eruption that began 430 feet (130 mt) below the sea and reached the surface on November 14, 1963. The eruption continued until June 5, 1967, when the island reached its maximum size of 1 square mile (2.7 sq km) and its maximum height of 509 feet (155 mt) above sea level.
In 1965, Iceland declared Surtsey a nature reserve, and today, only scientists are permitted to set foot on the island so that natural ecological succession can proceed without interference from the outside world.
In the spring of 1965, the first plant was spotted growing on Surtsey, mosses appeared in 1967, and lichens were first seen in 1970. During Surtsey's first 20 years of life, 20 different species of plants were observed, with 10 becoming fully established. Once birds began nesting on the island, their droppings improved the soil, and this allowed more plant species to grow. By 2008, 69 species of plant were growing on Surtsey.
Three years after the eruptions ended, birds began nesting on Surtsey, including gulls and Atlantic puffins. Surtsey is also being used by migrating birds, including swans, geese, and even ravens. By 1983, seals were breeding on Surtsey, which in turn attracted orcas who have made the waters around the island their home.
In 2008, UNESCO declared Surtsey a World Heritage Site, and today, scientists visiting the island must carefully check themselves and their belongings to make sure that no seeds are accidentally introduced onto the island. In 2009, a webcam was placed on Surtsey.
Erosion caused by waves is causing Surtsey to shrink, and as of 2012, its surface area was down to .5 square miles (1.3 sq km). NASA estimates that Surtsey will remain above the sea only for another 100 years.
Hunga Tonga-Hunga Ha'apai - Tonga
In December 2014, a submarine volcano erupted within the Tongan Islands located in the southwest Pacific. The volcanic ash combined with seawater and a chemical reaction took place that allowed the island to quickly solidify in a process similar to the creation of Surtsey.
When NASA scientists visited the island in October 2018, they found it was covered in light-colored, sticky clay mud, the origins of which mystified the scientists. Researcher Dan Slayback of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a blog post, "We didn't really know what it was and I'm still a little baffled of where it's coming from."
The new island is already home to pink flowering plants as seen in the picture at the beginning of this article, sooty tern birds, and strangely, barn owls. But, like Surtsey, Hunga Tonga-Hunga Ha'apai is rapidly eroding due to heavy rains, and NASA has modified its estimate of the lifespan of the new island down from 30 years to around a decade.
Nishinoshima (Ogasawara) - Japan
In 1974, fresh volcanic eruptions enlarged a known underwater volcano's caldera, and a new island was born. In November 2013, a fresh eruption began, and by July 2016, Nishinoshima was 1 square mile (2.7 sq km) in size with a height of 466 feet (142 mt).
Further eruptions occurred, with the latest in July 2020, enlarging Nishinoshima to 1.6 square miles (4.1 sq km). As with the other new volcanic islands, Japanese authorities are preventing external species from being introduced onto Nishinoshima.
Today, the plants goosegrass and purslane are growing on Nishinoshima. Birds nesting on the island include masked boobies, Gannets, and bramblings. A pod of dolphins has begun calling the waters around Nishinoshima home, along with short-finned pilot whales and Humpback whales.
Life finds a way
In the 1993 film Jurassic Park, Dr. Ian Malcolm, played by Jeff Goldblum, says, "No. I'm, I'm simply saying that life, uh ... finds a way." Life has found a way on three of Earth's newest volcanic islands, and it may have also 4,000 million years ago.