¶ … Alien Life on Earth
Scientists believe that all known life forms descended from a single common ancestor, a microbe that lived approximately 3.5 -- 3.8 billion years ago. Their belief is based on an understanding that all life forms have liquid water as their foundation, and they contain the same "building blocks" (Toomey 26). Researchers in the new field of synthetic biology have raised questions about another kind of living organism, independent of the building blocks already understood and unrelated to the last universal common ancestor (LUCA) from which all known life forms came. It is an intriguing idea that is attracting more interest as scientists continue to find evidence of this alien, or "weird" life on earth. The weird life is said to inhabit what is called the shadow biosphere.
Because little is known about weird life, scientists are considering myriad possibilities. The basic molecule might be other than DNA, for example, or its foundation might be ammonia, liquid methane or another substance besides water (Toomey). It is possible weird life exists in extremely inhospitable places, which would be one way of explaining why scientists know so little...
It is even possible, as some scientists suggest that weird life exists in some type of symbiotic relationships with known life forms. As Toomey points out, these could be organic compounds, enzymes and even genes. The possibilities are limitless, which is why scientists are so intrigued. As Toomey further points out, scientists are excited about weird life for the opportunity created to compare it to known life forms, examining both the commonalities and the differences. The science of biology would fully mature, Toomey suggests, as scientists would be able to define the universal laws of biology, just as physicists since Sir Isaac Newton have uncovered universal laws of physics.
In his brief article, Toomey raises more questions than he answers. A popular magazine such as Discover, written for the lay reader with a strong interest in science, aims to inform its audience of some of the latest trends in research and provide an overview of scientists' questions and findings. Two questions that can inform future research are these: How did weird life originate and where can it be found today on Earth and in space?
The second question is easier to answer…
