Now It's Time for Biologists to Take A Cosmic Perspective
THE United States National Academy of Sciences is asking an ancient question: How on Earth did organic life arise? It says that the search for answers should be an important part of the United States space program. Since people have been asking this question for millenniums, the board's interest might seem prosaic. What's remarkable is the board's cosmic perspective.
In its new report - ``The Search for Life's Origins'' - it urges scientists to look out from Earth upon the solar system and the stars to understand what happened here.
``A comparative study of planets is essential to an understanding of the relationship between planetary development and the origin and evolution of living systems,'' the report notes. It adds, ``The first goal is to understand the processes responsible for the chemical evolution of organic matter in the outer solar system.''
Now there's a new environment for biologists! After centuries of cataloging fossils, categorizing species, and brewing primordial ``soups'' in their laboratories, the Space Studies Board challenges them to look throughout the solar system and beyond for at least part of the answer to the question of origins.
Although no signs of actual life have yet been found beyond Earth, life's precursors - various organic molecules - are found throughout the solar system and in interstellar clouds. The elements essential to organic life - hydrogen, carbon, oxygen, nitrogen, sulfur, and phosphorus - are abundant all over the cosmos.
Also, there is growing suspicion that comets and asteroids impacting the primitive Earth could have seeded it with life-forming chemicals. Indeed, a second major goal in comparative plantology, the board says, ``is to understand how the conditions for chemical evolution and the origin of life were influenced by the physical and chemical development of the terrestrial planets.''
The Space Studies Board expects the Bush administration, Congress, and the scientific community to take this report seriously. The board's job is to analyze various fields of space science and recommend research strategies for the United States to follow.
To this end, its current report includes a number of recommendations. Overall, it urges a marriage of space research with traditional Earth-based biological science, including experiments on how chemical evolution may have led to organic life.
When it comes to space missions, the ``highest priority'' among the major recommendations is the study of Mars. The board explains: ``Mars is the only other object in the solar system on which an earlier origin of life could have left a well-preserved exposed record.''
The report also urges more study of comets, asteroids, and the moon. The giant outer planets and their moons where many organic chemical processes occur are also prime targets. In short, the board makes a strong case for solar-system exploration, especially Mars research, as essential to understanding organic life.
It even boosts a search for life beyond our solar system by looking for signs of planets around other stars and listening for alien radio signals.
The thrust of the board's report is clear. Humanity cannot understand life on Earth - indeed, cannot fully understand itself - except in a cosmic perspective.
Philosophers have said this for millenniums. But, until recently, practical biologists have seen little need to look beyond Earth to pursue their science. Now they know they have no choice but to broaden their horizon.