Year: 2021
Type: article
Abstract: A central need in the field of astrobiology is generalized perspectives on life that make it possible to differentiate abiotic and biotic chemical systems McKay (2008). A key component of many past and future astrobiological measurements is the elemental ratio of various samples. Classic work on Earth's oceans has shown that life displays a striking regularity in the ratio of elements as originally characterized by Redfield (Redfield 1958; Geider and La Roche 2002; Eighty years of Redfield 2014). The body of work since the original observations has connected this ratio with basic ecological dynamics and cell physiology, while also documenting the range of elemental ratios found in a variety of environments. Several key questions remain in considering how to best apply this knowledge to astrobiological contexts: How can the observed variation of the elemental ratios be more formally systematized using basic biological physiology and ecological or environmental dynamics? How can these elemental ratios be generalized beyond the life that we have observed on our own planet? Here, we expand recently developed generalized physiological models (Kempes et al. 2012, 2016, 2017, 2019) to create a simple framework for predicting the variation of elemental ratios found in various environments. We then discuss further generalizing the physiology for astrobiological applications. Much of our theoretical treatment is designed for in situ measurements applicable to future planetary missions. We imagine scenarios where three measurements can be made-particle/cell sizes, particle/cell stoichiometry, and fluid or environmental stoichiometry-and develop our theory in connection with these often deployed measurements.
Source: Bulletin of Mathematical Biology
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,780
Awards: G4768352037, Convergence: RAISE: Linking the adaptive dynamics of plankton with emergent global ocean biogeochemistry, HOW DO WE CONTEND WITH THE TRULY ALIEN? MOST STRATEGIES FOR BIOSIGNATURE DETECTION RELY UPON FINDING FEATURES KNOWN TO BE ASSOCIATED WITH TERRESTRIAL LIFE SUCH AS PARTICULAR CLASSES OF MOLECULES BUT LIFE MAY BE VASTLY DIFFERENT ON OTHER WORLDS. THIS WORK WILL FURTHER DEVELOP SEVERAL TRULY AGNOSTIC APPROACHES NONE OF WHICH PRESUPPOSE A PARTICULAR MOLECULAR FRAMEWORK. SOME OF THESE AREAS WILL INVOLVE NEW LINES OF INQUIRY THAT CAN BE ACCOMPLISHED USING INSTRUMENTATION THAT IS EITHER HIGH HERITAGE OR ON A PATH TOWARD HIGH TRL. OTHERS WILL NECESSITATE THE DESIGN OF COMPLETELY NEW ANALYTICAL TECHNIQUES. OUR NAI WILL NOT ONLY ADVANCE EACH OF THESE AGNOSTIC DETECTION CONCEPTS SEPARATELY BUT ALSO JOIN THESE TRADITIONALLY FRAGMENTED EFFORTS IN A UNIFIED RESEARCH PROGRAM ONE THAT DRAWS LESSONS FROM OUR OPERATIONAL EXPERIENCES IN PLANETARY EXPLORATION THUS FAR. WE WILL BRING TOGETHER THEORETICIANS AND EXPERIMENTALISTS AS AN INCUBATOR FOR NEW AGNOSTIC LIFE DETECTION APPROACHES CREATE A COMMON TRAINING SET OF BIOTIC AND ABIOTIC TEST SUBSTRATES ESTABLISH LIKELIHOODS AND THRESHOLDS WITH PROBABILISTIC MODELS AND DEVELOP A BROADER FORMULATION OF THE LADDER OF LIFE. IN THE PROCESS WE WILL MERGE THE BROAD AND NARROW ENDS OF THE LIFE DETECTION SPECTRUM INTO A COLLECTIVE DIALOGUE ONE THAT WILL HELP US SYNTHESIZE PRIORITIZE EVALUATE AND STRENGTHEN THE SEARCH FOR LIFE ON FUTURE SPACE MISSIONS., G8842413123
OpenAlex ID: W3097102319