RESEARCH BASE
Search 3,721 documents across 34 fields — every claim tier-rated by evidence
3,633 are the core, quality-scored corpus (34 lettered sections — see How We Work); the remaining 88 are cross-corpus synthesis documents (68 InterDocs, 12 Connections, 8 Theories) also indexed here.
2,331 results for "Type Ia supernova" — page 97 of 117
R_4_17 — Biogeography & the Wallace Line: Continental Drift, Island Life, and Distribution Puzzles
Biogeography — the study of the geographic distribution of organisms, both past and present — has been central to evolutionary biology since Alfred Russel Wallace (1823–1913) identified the sharp faunal boundary between
R_4_03 — Nervous System Evolution: From Nerve Nets to Brains
The nervous system — the most complex organ system in animals — evolved once (possibly twice) from electrically excitable cells in the common ancestor of bilaterians and cnidarians, approximately 600–700 million years ag
R_3_07 — Embryology and Morphogenesis: How Bodies Take Shape
Embryology — the study of how a single fertilized cell becomes a complex multicellular organism — is one of biology's most profound mysteries. From the discovery by Karl Ernst von Baer (1828) that embryos of different sp
R_3_11 — Microevolution and Rapid Adaptation
Microevolution — changes in allele frequencies within populations over generations — is the fundamental engine of biological adaptation. Once assumed to operate too slowly to observe directly, research over the past 50 y
R_3_14 — Evolution of Aging and Senescence
Aging — the progressive decline in physiological function and increase in mortality rate with time — is one of evolution's deepest puzzles: why would natural selection, which optimizes fitness, permit organisms to deteri
R_3_02 — Horizontal Gene Transfer in Complex Life
For decades, the "tree of life" was the central metaphor of evolutionary biology — species branching neatly from common ancestors through vertical gene transmission (parent to offspring). This metaphor is now BROKEN, at
R_3_06 — Altruism and Cooperation in Nature
Altruism — behavior that reduces the actor's fitness while increasing the recipient's — presents a fundamental puzzle for evolutionary theory: how can natural selection favor genes that reduce their bearer's reproduction
R_3_20 — CRISPR & Gene Editing Technology
CRISPR-Cas9 is the most transformative biological technology since PCR, enabling precise, programmable editing of DNA in virtually any organism. The system was adapted from a bacterial immune defense mechanism first iden
R_3_10 — Protein Evolution and Molecular Machines
Proteins are the molecular workhorses of life — catalyzing reactions, building structures, transporting cargo, transmitting signals, and defending against pathogens. They are also some of biology's most astonishing molec
R_3_09 — Molecular Phylogenetics and Tree of Life
Molecular phylogenetics — reconstructing evolutionary relationships from DNA, RNA, and protein sequences — has revolutionized our understanding of the tree of life since Carl Woese's landmark 1977 discovery, using small-
R_3_03 — Evo-Devo: Evolutionary Developmental Biology
Evolutionary developmental biology ("evo-devo") reveals one of biology's most profound discoveries: the same small set of "toolkit" genes (Hox, Pax6, Sonic hedgehog, BMP, Wnt, etc.) controls body plan development across
R_5_08 — Human Microbiome: Gut Ecology and Symbiotic Partnerships
The human microbiome — the vast community of trillions of microorganisms (bacteria, archaea, fungi, viruses) that inhabit the human body, primarily the gastrointestinal tract — is now recognized as a critical organ-like
R_5_11 — Coral Biology: Symbiosis, Bleaching, and Reef Building
Coral reefs — often called the "rainforests of the sea" — are among Earth's most biodiverse and productive ecosystems, occupying less than 0.1% of the ocean floor yet supporting approximately 25% of all marine species. T
R_5_12 — Deep-Sea Biology: Hadal Zone Life, Pressure, and Extreme Organisms
The deep sea — defined as depths below 200 meters (the photic zone boundary) — constitutes the largest habitat on Earth by volume, yet remains among the least explored. This vast realm is divided into depth zones: the me
R_5_02 — Megafauna Extinction: Quaternary Losses and the Overkill Debate
Between ~50,000 and 10,000 years ago, Earth lost the majority of its large-bodied animals (megafauna >44 kg) — woolly mammoths, ground sloths, saber-toothed cats, giant wombats, moa, and dozens of other spectacular speci
R_5_03 — Domestication of Plants and Agriculture
The domestication of plants — one of the most transformative events in human history — began independently in at least 10 geographic centers between ~12,000 and 5,000 years ago. The Fertile Crescent (wheat, barley, lenti
R_2_05 — Missing Fossil Record and Punctuated Equilibrium
Darwin himself called the fossil record "the most obvious and gravest objection which can be urged against my theory" — because if evolution occurred through gradual transformation, we should find smooth transitional seq
R_2_04 — Homo Floresiensis: The Hobbit Mystery
In 2003, a team of Australian and Indonesian archaeologists discovered a tiny, near-complete hominin skeleton in Liang Bua cave on the island of Flores, Indonesia. Designated Homo floresiensis (Brown et al. 2004, Nature)
R_2_12 — Tool Use in Animals: Corvids, Primates, Dolphins, and Cognitive Evolution
Tool use — the employment of an external object to alter the form, position, or condition of another object or organism — was once considered uniquely human, a defining cognitive threshold separating Homo sapiens from al
R_2_01 — Human Brain Evolution and the Cognitive Revolution
The human brain tripled in size over 3 million years — from ~400 cm³ (Australopithecus) to ~1,400 cm³ (modern Homo sapiens). This is the most dramatic encephalization in the history of life, and NO consensus exists on wh
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