Astrobiology not only investigates how early life took hold of our planet but also life on other planets - both in our Solar System and beyond - and their potential for habitability. The book take readers from the scars on planetary surfaces made by space rocks to the history of the Solar System narrated by those space rocks as well as exoplanets in other planetary systems. But the true question is how life arose here or elsewhere. Modern comparative genomics has revealed that Darwin was correct; a set of highly conserved genes and cellular functions indicate that all life is related by common ancestry. The Last Universal Common Ancestor or LUCA sits at the base of the Tree of Life. However, once that life took hold, it started to diversify and form complex microbial communities that are known as microbial mats and stromatolites. Due to their long evolutionary history and abundance on modern Earth, research on the biological, chemical and geological processes of stromatolite formation has provided important insights into the field of astrobiology. Many of these microbialite-containing ecosystems have been used as models for astrobiology, and NASA mission analogs including Shark Bay, Pavilion and Kelly Lakes. Modern microbialites represent natural laboratories to study primordial ecosystems and provide proxies for how life could evolve on other planets. However, few viral metagenomic studies (i.e., viromes) have been conducted in microbialites, which are not only an important part of the community but also mirror its biodiversity. This book focuses on particularly interesting sites such as Andean lake microbialites, a proxy of early life since they are characterized by very high UV light, while Alchichica and Bacalar lakes are characterized by high-salt and oligotrophic waters that nurture stromatolites. However, it is only the oasis of Cuatro Cienegas Basin in Mexico that stored past life in its marine sediments of the Sierra de San Marcos. This particular Sierra has a magmatic pouch that moves the deep aquifer to the surface in a cycle of sun drenched life and back to the depths of the magmatic life in an ancient cycle that now is broken by the overexploitation of the surface water as well as the deep aquifer in order to irrigate alfalfa in the desert. The anthropocene, the era of human folly, is killing this unique time machine and with it the memory of the planet.

Carbon (C), Nitrogen (N) and Phosphorus (P) are three of the most important elements used to build living beings, and their uptake from the environment is consequently essential for all organisms. Photosynthesis is the process in which plants absorb atmospheric C as they grow and convert it to biomass. However, plants acquire N and P only when these are available in the soil solution, which makes these elements the most limiting nutrients in plant growth and productivity in most ecosystems. When plant residues and roots decompose, the C, N and P they contain is transformed primarily into soil organic matter (SOM) or C and N can release to the atmosphere. Recent interest on the global C, N and P cycles has focused attention on the different proportion of terrestrial C, N and P stored in different ecosystem pools. Cuatro Cienegas represents an exceptional place, since the plants are not the base of the food web, they are the microbial community, that recycle the elements essential for life. In this book we describe how this is an analog of early Earth.

The aim of this first book is to introduce the readers of the series to why Cuatro Cienegas Basin (CCB) is so unique, starting with the reason why astrobiologists became interested in this oasis in the first place; namely, the high diversity and abundance of stromatolites and microbial mats in continental waters to be found in the desert oasis. As NASA has long since discovered, the basin may offer the best analog of early Earth. In essence, CCB is a time machine that can take us far back and forth in time. In the respective chapters, the contributing authors explain the extraordinary microbial diversity of Cuatro Cienegas Basin from various perspectives. In order to do so, they explain their journey as well as the different tools used to unravel the basin's mysteries, such as: Why are there so many species in a place without food? How has life there survived the enormity of tectonic shifts through the ages, maintaining its ancient marine heritage?

This book takes readers on a journey through the history of water in the Coahuila desert. It starts by describing the beauty and mysteries of the landscape, and then explores the rock art of the original desert cultures in Coahuila, offering readers a glimpse of the sacred nature of water in the desert, as well as the rituals surrounding it. Moving on to the colonial times and the post- independence development of the region, it discusses early water management, and explores how water is managed in modern times, as well as the legal complications of the law, and how these faulty laws, designed for less arid regions, have affected a highly diverse wetland, the Cuatro Cienegas oasis. The book then examines the biological consequences of the water loss for the aquatic plants and animals in Churince - a now extinct system within Cuatro Cienegas. Further, it addresses how even bacteria can become extinct in this hyper-diverse microbial oasis. Lastly, after this despair and sense of loss, the book provides hope, offering suggestions for how we can transform the future, from a social and educational point of view as well as through good science and changes in policy.

Astrobiology not only investigates how early life took hold of our planet but also life on other planets - both in our Solar System and beyond - and their potential for habitability. The book take readers from the scars on planetary surfaces made by space rocks to the history of the Solar System narrated by those space rocks as well as exoplanets in other planetary systems. But the true question is how life arose here or elsewhere. Modern comparative genomics has revealed that Darwin was correct; a set of highly conserved genes and cellular functions indicate that all life is related by common ancestry. The Last Universal Common Ancestor or LUCA sits at the base of the Tree of Life. However, once that life took hold, it started to diversify and form complex microbial communities that are known as microbial mats and stromatolites. Due to their long evolutionary history and abundance on modern Earth, research on the biological, chemical and geological processes of stromatolite formation has provided important insights into the field of astrobiology. Many of these microbialite-containing ecosystems have been used as models for astrobiology, and NASA mission analogs including Shark Bay, Pavilion and Kelly Lakes. Modern microbialites represent natural laboratories to study primordial ecosystems and provide proxies for how life could evolve on other planets. However, few viral metagenomic studies (i.e., viromes) have been conducted in microbialites, which are not only an important part of the community but also mirror its biodiversity. This book focuses on particularly interesting sites such as Andean lake microbialites, a proxy of early life since they are characterized by very high UV light, while Alchichica and Bacalar lakes are characterized by high-salt and oligotrophic waters that nurture stromatolites. However, it is only the oasis of Cuatro Cienegas Basin in Mexico that stored past life in its marine sediments of the Sierra de San Marcos. This particular Sierra has a magmatic pouch that moves the deep aquifer to the surface in a cycle of sun drenched life and back to the depths of the magmatic life in an ancient cycle that now is broken by the overexploitation of the surface water as well as the deep aquifer in order to irrigate alfalfa in the desert. The anthropocene, the era of human folly, is killing this unique time machine and with it the memory of the planet.

The aim of this first book is to introduce the readers of the series to why Cuatro Cienegas Basin (CCB) is so unique, starting with the reason why astrobiologists became interested in this oasis in the first place; namely, the high diversity and abundance of stromatolites and microbial mats in continental waters to be found in the desert oasis. As NASA has long since discovered, the basin may offer the best analog of early Earth. In essence, CCB is a time machine that can take us far back and forth in time. In the respective chapters, the contributing authors explain the extraordinary microbial diversity of Cuatro Cienegas Basin from various perspectives. In order to do so, they explain their journey as well as the different tools used to unravel the basin's mysteries, such as: Why are there so many species in a place without food? How has life there survived the enormity of tectonic shifts through the ages, maintaining its ancient marine heritage?

Carbon (C), Nitrogen (N) and Phosphorus (P) are three of the most important elements used to build living beings, and their uptake from the environment is consequently essential for all organisms. Photosynthesis is the process in which plants absorb atmospheric C as they grow and convert it to biomass. However, plants acquire N and P only when these are available in the soil solution, which makes these elements the most limiting nutrients in plant growth and productivity in most ecosystems. When plant residues and roots decompose, the C, N and P they contain is transformed primarily into soil organic matter (SOM) or C and N can release to the atmosphere. Recent interest on the global C, N and P cycles has focused attention on the different proportion of terrestrial C, N and P stored in different ecosystem pools. Cuatro Cienegas represents an exceptional place, since the plants are not the base of the food web, they are the microbial community, that recycle the elements essential for life. In this book we describe how this is an analog of early Earth.

This book takes readers on a journey through the history of water in the Coahuila desert. It starts by describing the beauty and mysteries of the landscape, and then explores the rock art of the original desert cultures in Coahuila, offering readers a glimpse of the sacred nature of water in the desert, as well as the rituals surrounding it. Moving on to the colonial times and the post- independence development of the region, it discusses early water management, and explores how water is managed in modern times, as well as the legal complications of the law, and how these faulty laws, designed for less arid regions, have affected a highly diverse wetland, the Cuatro Cienegas oasis. The book then examines the biological consequences of the water loss for the aquatic plants and animals in Churince - a now extinct system within Cuatro Cienegas. Further, it addresses how even bacteria can become extinct in this hyper-diverse microbial oasis. Lastly, after this despair and sense of loss, the book provides hope, offering suggestions for how we can transform the future, from a social and educational point of view as well as through good science and changes in policy.