What is a biovermiculation or bioverm?

A biovermiculation, frequently called bioverm, is a microbial community exhibiting a patterned growth within an extreme environment. Bioverms are of interest in overlapping natural-science disciplines such as geomicrobiology, speleology and astrobiology. Michael Lemonick, who also points out the significance of biosignatures and biofilms for astrobiological research, inspiringly illustrates the artlike biostructures of bioverms, which make

patterns on the cave walls, including spots, lines, and even networks of lines that look almost like hieroglyphs. Astrobiologists have come to call these patterns biovermiculations, or bioverms for short, from the word “vermiculation ,” meaning decorated with “irregular patterns of lines, as though made by worm tracks.”  

It turns out that patterns like these aren't made only by microorganisms growing on cave walls. “It happens on a variety of different scales, usually in places where some resource is in short supply,” says Keith Schubert, a Baylor University engineer who specializes in imaging systems and who came to Cueva de Villa Luz [a poisonous cave near Tapijulapa in Mexico] to set up cameras for long-term monitoring inside the cave. Grasses and trees in arid regions create bioverm patterns as well, says Schubert. So do soil crust, which are communities of bacteria, mosses, and lichens that cover the ground in deserts.

                                                                                              Michael Lemonick, 2014.

Are these patterns, which are based on simple rules of growth and competition for resources, a universal signature of life?

Keywords: biology, ecology, pattern formation, growth patterns, competition for resources, network architectures, scaling.

Reference
Michael D. Lemonick: The Hunt for Life Beyond Earth. National Geographic July 2014, 226 (1), 26-45.

What is a biofilm?

A biofilm is

a community of microbes bound together in a viscous, gooey blob. 

                                                                                              Michael Lemonick, 2014.

Such biofilms are ubiquitous on Earth—likely growing in your shower and frequently found on other inorganic surfaces in wet environments as well as on organic surfaces including those of plants. If found beyond Earth (for example, in caves of Mars), biofilms would take on the role of exciting biosignatures for alien life and thrive—indicating that we, or at least “our” microbes, are not alone.

Reference
Michael D. Lemonick: The Hunt for Life Beyond Earth. National Geographic July 2014, 226 (1), 26-45.

What are biosignatures?

Biosignatures are

visual or chemical clues that signal the presence of life, past or present, in places where scientists won't have the luxury of doing sophisticated laboratory experiments. 

                                                                                              Michael Lemonick, 2014.

Those places include niche environments on Earth as well as possible habitats on other planets and moons of our solar system and on exoplanets and their moons.

Reference
Michael D. Lemonick: The Hunt for Life Beyond Earth. National Geographic July 2014, 226 (1), 26-45.