Sage Journals posts astrobiology collection

SAGE Journals used a May 18 social media thread to direct readers to a new Astrobiology special collection examining whether life on Earth may have begun on land rather than in the sea. The collection, titled “An Origin of Life on Land,” was described in a May 14 release as a set of papers bringing together researchers from geology, chemistry, planetary science, molecular biology and systems chemistry. The issue focuses on terrestrial environments including volcanic landscapes, freshwater hydrothermal systems, evaporative settings, crater lakes and shorelines as possible sites for early prebiotic chemistry. SAGE linked readers to the collection on its journal platform and urged them to consult the papers there. ### What exactly did SAGE post? SAGE Journals posted a thread on May 18 highlighting the Astrobiology collection and framing it around evidence for land-based origin scenarios, according to the social media post referenced in the announcement materials. The thread directed readers to the publisher’s site for the full set of papers. The May 14 release identified the collection as “An Origin of Life on Land” in Astrobiology, Volume 26, issues 3–4. (eurekalert.org) The release said the papers examine “growing evidence” that life may have emerged within networks of terrestrial environments on early Earth. ### What is the scientific claim the collection is examining? The May 14 release said the collection reflects a shift from a long-running focus on deep-sea hydrothermal vents toward increased investigation of hot springs and other chemically dynamic land environments. (eurekalert.org) The papers do not present a single settled answer; they assemble arguments and evidence for terrestrial settings as plausible sites for life’s emergence. David Deamer, quoted in the release, said “liquid water alone is probably insufficient for life to originate.” Bruce Damer said the question is whether a world contains environments that can concentrate organics, sustain chemical evolution and drive greater molecular complexity over time. The release said the editors propose that early Earth may have contained multiple localized “urable zones” that supported different stages of prebiotic chemistry and protocell evolution. (eurekalert.org) ### Which environments are the papers focusing on? The collection description names volcanic landscapes, freshwater hydrothermal systems, evaporative environments, crater and soda lakes, and transiently saline shorelines as candidate settings. The release said those environments could have provided the chemical complexity and repeated environmental cycling needed for nonliving chemistry to move toward evolving protocell populations. (eurekalert.org) Wet-dry cycling is one recurring theme. A 2020 Astrobiology paper by Bruce Damer and David Deamer said fluctuating volcanic hot spring pools could support protocell formation because hydration and dehydration cycles can help synthesize lipid-encapsulated polymers. That paper compared land-based pool scenarios with oceanic vent scenarios and laid out tests for the hypothesis. (eurekalert.org) ### Does the special issue say the sea-origin idea is ruled out? The May 14 release said the issue “does not argue for a single exclusive setting” for life’s origins. Instead, it described the collection as advancing a systems-level view in which life may have arisen through interactions among diverse environments across volcanic landmasses. A separate Astrobiology paper available through SAGE compares seawater and terrestrial hot spring chemistry and says hot springs associated with volcanic land masses may offer conditions more conducive to self-assembly and polymerization than seawater. (journals.sagepub.com) That comparison shows the debate remains centered on which environments best support the chemistry needed before biology began. (eurekalert.org) ### Why is an astrobiology journal interested in where life began on Earth? Astrobiology connects origin-of-life research on Earth to the search for life elsewhere. The 2020 Damer-Deamer paper said the land-based hypothesis also has implications for where life might have emerged on Mars or Saturn’s moon Enceladus. The May 14 release said the special issue draws on laboratory experiments, geological discoveries, planetary science observations and field studies of terrestrial analog environments. (journals.sagepub.com) That mix of disciplines is central to astrobiology’s approach because researchers use Earth settings as analogs when assessing habitability on other worlds. ### Where can readers find the next step? SAGE said the collection is available through its Astrobiology journal site as Volume 26, issues 3–4. (journals.sagepub.com) The publisher’s release identified Bruce Damer and David Deamer as guest editors, and the papers are already posted in the online special collection for readers who want the full articles and abstracts. (eurekalert.org)