14 DAY TRIAL // For many years, scientists have been wondering as to whether the environment in which the first lifeforms evolved on Earth was hot or cold. In a new study, experts shows that the time evolution requires to work its magic is reduced considerably if the processes take place in warm environment.
One of the main implications for the early Earth temperature question is whether life had enough time since it first appeared to develop to its current level of complexity. If not, then the conclusions would naturally be that it had some help, or a nudge in the right direction, along the way.
But a team of investigators at the University of North Carolina in Chapel Hill (UNC) shows in a new study that this was not the case. They conducted an analysis of chemical reactions that may have taken place on Earth billions of years ago, and determined that evolution may have occurred fast enough.
Essentially, what the team did was investigate how temperature levels reflect upon extremely slow chemical reactions. They found that heat boosts their speed.
A major implication of this is that the billions of years elapsed since the first organisms occurred represent a sufficiently large period of time to explain the existence of such complex and diverse life on Earth today.
In past studies, various research groups proposed different time frames that they believed were needed to explain life how it is today. If we take into account a warm Earth, the UNC team says, then the time needed for evolution to take place is drastically diminished.
Details of the new investigation were published in the December 1 online early issue of the esteemed journal Proceedings of the National Academy of Sciences (PNAS), SpaceRef reports.
The UNC group, coordinated by lead investigator Richard Wolfenden, PhD, determined in the experiments that certain chemical reactions take place over 1 to 2 billion years, in the absence of catalysts.
Inside living organisms, special proteins called enzymes play the role of catalysts. These molecules are capable of starting various chemical reactions – by themselves or in tandem – and life as we know it is heavily dependent on their function.
Over time, the enzymes have evolved as well, reaching a high degree of complexity as they did so, explains Wolfenden, who is the Alumni distinguished professor of biochemistry and biophysics at the UNC School of Medicine.
As the group was measuring the rate at which slow reactions occur, “it gradually dawned on us that the slowest reactions are also the most temperature-dependent,” the team leader says.
In one reaction, he adds, increasing the temperature from 25 to 100 degrees Celsius – a 400 percent rise – boosted the reaction rate by about 10 million times over.
As such, the UNC team proposes that temperatures played a much more important role in the development of chemistry that would later underlie life on our planet than previously calculated.
The new work was sponsored by the US National Institutes of Health (NIH) National Institute of General Medicine (NIGM).