The Signatures of Intelligence

Blue Marble 2012 - Can you detect life in this picture? 

Looking for lifeforms out there in the Milky Way Galaxy is a very difficult task. Why so hard? You might say to yourself, "Well, I'll know a living thing when I see it." And generally, with the exception of a sea sponge or a slime mold, that is basically true. But, try recognizing something hundreds of millions of miles away, as is the case with Mars, or hundreds and hundreds of light years away, as is the case with most of the exoplanets we are discovering. In light of such a complication, the business of looking for life comes down to looking for signs of life. In order to do this, one must understand what kinds of life signatures can exist. A knowledge of all the different ways that lifeforms can alter their environment can give us an itemized list of what to look for on other worlds.

So, when scientists get a whiff of an alien atmosphere, as is the case sometimes when an exoplanet is detected by Astronomical Transit, they breakdown the light via spectroscopy and sift through the results looking for key atmospheric gases like oxygen or methane. These kinds of gases are signs of life, as far as LAWKI is concerned (Life As We Know It)...these gases in particular are waste products of the living metabolisms of millions upon millions of creatures. Another sign of life for LAWKI is water, and indeed water is being sought after like the holy grail as far as exoplanet discoverers and astrobiologists are concerned. Just recently, there has been chatter about how to discover exo-oceans - oceans on other worlds - by understanding how light from the parent star can reflect off of that ocean. It is crude to look for life in such a way, but at the moment our options are quite limited. What we need is to broaden our thinking on how particular biological patterns leave particular signatures in the environment they inhabit.

Of all the potential biological patterns to choose from, Intelligence seems the most daunting. In some ways, it feels like the easiest...just look at how humanity has altered the surface of the Earth...all the roads and cities and agriculture and all that. That should be an easy kind of thing to detect from space, right? However, the problem lies in how unusual it is. Humans have only been altering the Earth on this global scale for a relatively short time, and over that time, trends tend to be short lived. And, we also seem to be doing this civilization thing by ourselves. Since we don't have other civilizations to compare ourselves to, its quite difficult to say what is normal about this human-style of intelligence...or rather, what is universal about it. Is the release of carbon dioxide, for example, en mass into the atmosphere an indication of the presence of intelligence if we found such a circumstance on some distant exoplanet? Hard to say. However, it is obvious that intelligence can alter the environment in particular ways.

An animation illustrating how Intelligence alters the environment

Luckily, we do have something on this good Earth to help us understand intelligence, and from that deduce what universal patterns of intelligence can exist. Several key organism alive and kicking on the Earth apart from humanity do show signs of remarkable intelligence, despite their general lack of cities, tech support, and tea ceremonies. Mammals, above all others, show the most collective signs of intelligence. They seem to have the most complex social organizations and survival strategies. Individual mammals, apart from the humans, stand out above the rest: chimpanzees and bonobos, dolphins, whales and other cetaceans generally show significant advancement in several key components of intelligence...things like memory and math. Non-mammal organisms also show signs of intelligence. Several species of birds, including the highly above average New Caledonian Crow and the African Grey Parrot, show indications of intelligent behavior that rivals that of mammals. Scientists are working to understand how intelligence can evolve, what commonalities exist among intelligent creatures, and how those commonalities can translate into detectable signs of life elsewhere in the cosmos. Any and all relevant material relating to the quest to understand the Intelligence Question and its relevance to the Search for Life will be discussed here in the future. Until then, happy hunting =)

A New Caledonian Crow using a sequence to tools.