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.
68 results for "observer selection" — page 3 of 4
L_3_09 — HLA Diversity and Immune System Evolution
The Human Leukocyte Antigen (HLA) system — the human version of the Major Histocompatibility Complex (MHC) found in all jawed vertebrates — is the most polymorphic gene region in the entire human genome. Located on chrom
L_3_13 — Human Accelerated Regions: What Makes Us Genetically Unique
Human Accelerated Regions (HARs) are short segments of the genome that were highly conserved across millions of years of mammalian evolution — indicating strong functional constraint — but then underwent a burst of rapid
L_3_05 — Blood Type Genetics and the ABO System
Blood group genetics represents one of the earliest and most clinically important applications of Mendelian inheritance in human biology. Karl Landsteiner's discovery of the ABO blood group system (1900–1901) — which ear
L_3_03 — Lactase Persistence and Gene-Culture Coevolution
Lactase persistence — the ability of adults to digest the milk sugar lactose — is the most thoroughly documented case of gene-culture coevolution in the human species. The ancestral mammalian condition is lactase non-per
H_2_13 — Reproducibility in Archaeology: Method Reliability Assessment
Reproducibility — the ability of independent researchers to produce the same results using the same methods on the same or equivalent materials — is a cornerstone of scientific credibility. Yet archaeology faces unique c
R_4_12 — Mimicry: Batesian, Müllerian, and Aggressive Deception
Mimicry — the resemblance of one organism (the mimic) to another (the model) or to an environmental feature, evolved to deceive a third party (the signal receiver, typically a predator) — is one of the most elegant demon
R_4_09 — Parasitism and Host-Parasite Coevolution
Parasitism — a symbiotic relationship in which one organism (the parasite) benefits at the expense of another (the host) — is arguably the most common lifestyle on Earth. By some estimates, over 40% of all described spec
R_3_08 — Speciation Mechanisms and Reproductive Isolation
Speciation — the process by which one species splits into two or more reproductively isolated lineages — is the engine of biodiversity. Ernst Mayr's biological species concept (1942) defines species as groups of interbre
R_3_12 — Evolution of Sex and Reproduction
Sex — the rearrangement of genetic material from two parents to produce genetically unique offspring — is one of the most fundamental yet puzzling features of life. Sexual reproduction involves enormous costs: the "twofo
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_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_5_09 — Color in Nature: Structural Color, Pigmentation, and Signaling
Color in nature serves functions spanning camouflage, warning, mate attraction, thermoregulation, and protection from UV radiation — produced through two fundamentally different mechanisms: pigmentary color (selective ab
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_5_04 — Eusociality: Ants, Bees, and Termites
Eusociality — the highest level of social organization in the animal kingdom, characterized by reproductive division of labor (some individuals forgo reproduction to help others reproduce), cooperative brood care, and ov
R_5_19 — Evolutionary Game Theory: Cooperation, Altruism, and Strategy in Nature
Evolutionary game theory applies mathematical game theory to biological evolution, explaining how natural selection favors strategies for survival and reproduction in competitive and cooperative interactions. The field's
R_2_14 — Recent Human Evolution: Lactase Persistence, Altitude Adaptation, and Malaria Resistance
Human evolution did not stop with the emergence of Homo sapiens ~300,000 years ago — natural selection has continued to shape human biology in response to agriculture, diet, disease, climate, and altitude, producing some
R_1_12 — History of Evolutionary Theory
Evolutionary theory — the unifying framework of modern biology — has itself undergone a remarkable evolution over more than two centuries. Pre-Darwinian ideas included Lamarck's transformism (1809), which proposed that o
F_3_14 — Domestication: How Humans Reshaped Species and Themselves
Domestication — the multigenerational process by which humans selectively breed wild species, producing organisms that are genetically, morphologically, and behaviorally distinct from their wild ancestors and dependent o
ZA_1_14 — The Measurement Problem: Quantum Mechanics' Deepest Puzzle
The measurement problem — arguably the deepest conceptual issue in all of physics — arises from a fundamental tension within quantum mechanics between two processes: (1) unitary evolution — the deterministic, continuous,
ZA_1_05 — Quantum Decoherence and the Measurement Problem
Quantum decoherence explains how the strange superposition behavior of quantum mechanics transitions into the definite, classical-looking world we observe — without requiring a mysterious "collapse" postulate. When a qua
BROWSE BY SECTION — 3,721 documents across 34 fields