Scientists have discovered that the rise of Earth’s first continents may have played a major role in making life possible.
According to a new study published in Terra Nova, the growth of ancient continents may have helped control the amount of boron in Earth’s early oceans, creating conditions that allowed the building blocks of life to survive.
Boron is a chemical element that scientists believe may have been important for the origin of life.
In particular, it can help stabilize certain sugars needed to form RNA, a molecule that many researchers think existed before DNA. RNA is considered one of the key ingredients for the development of early life.
However, boron only works within a narrow range. Too much boron can become harmful to living systems, while too little may not support the chemical reactions needed for life to begin.
The new study suggests that Earth’s earliest oceans may once have contained dangerously high levels of boron more than 3.7 billion years ago. At that time, large continents had not yet formed.
According to Brendan Dyck from the University of British Columbia Okanagan, the growth of continents may have acted like a natural chemical control system for the planet.
The researchers believe the key was a mineral called tourmaline, which contains boron and commonly forms in granite-rich continental rocks. Tourmaline is also known today as a colorful semi-precious gemstone.
As Earth’s continental crust slowly formed and expanded, more tourmaline developed within the rocks.
This mineral trapped large amounts of boron and prevented too much from remaining in the oceans. Over long periods of time, weathering of the continents gradually released smaller, more stable amounts of boron back into rivers and seas.
Eventually, boron levels may have settled into a range similar to that found in modern seawater, a balance that could have helped fragile molecules survive long enough to combine into more complex forms linked to life.
The findings suggest that Earth’s geology may have been just as important as its atmosphere or temperature in shaping the conditions needed for life to emerge.
The study may also affect how scientists search for life beyond Earth. Planets without granite-rich continents may struggle to maintain suitable levels of boron in surface water. For example, researchers say planets such as Mars may not have had the same chemical stability needed for life to develop.
The research highlights how the slow evolution of a planet’s interior can influence the chemistry of its oceans and surface. In other words, the formation of continents may have done more than reshape Earth’s surface—it may have quietly helped life get started billions of years ago.
Source: University of British Columbia.
