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.
507 results for "social brain hypothesis" — page 18 of 26
R_4_15 — Insect Evolution: Flight, Metamorphosis, and Mega-Diversity
Insects (class Insecta) are the most species-rich group of organisms on Earth — with over 1 million described species and an estimated 5–10 million total, they account for approximately 80% of all known animal species. T
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_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_05 — Coevolution — Arms Races, Mutualisms, and Red Queens
Coevolution — reciprocal evolutionary change between interacting species — is one of the most powerful engines of biological diversity. Leigh Van Valen's Red Queen hypothesis (1973) captured its essence: species must con
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_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_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_08 — Bipedalism — Why We Walk Upright and What It Cost Us
Bipedalism — habitual upright walking on two legs — is the defining characteristic of the hominin lineage, predating brain enlargement, tool use, and language by millions of years. The earliest evidence comes from Sahela
R_1_02 — The Cambrian Explosion
Between ~541 and ~520 million years ago, nearly ALL major animal body plans (phyla) appeared in the fossil record in an evolutionary "instant" — roughly 20 million years. Before this, life had been single-celled for ~3 b
R_1_18 — Mass Extinction Periodicity
The question of whether mass extinctions follow a periodic pattern — recurring at regular intervals driven by astronomical or geological cycles — has been one of the most provocative and contentious hypotheses in paleont
R_1_14 — Biofilms: Microbial Communities, Quorum Sensing, and Cooperation
Biofilms are structured communities of microorganisms — bacteria, archaea, fungi, and algae — attached to surfaces and embedded in a self-produced matrix of extracellular polymeric substances (EPS): polysaccharides, prot
S_4_05 — Asteroid Deflection and Planetary Defense
Asteroid and comet impacts represent the only existential risk with a proven extinction track record — the Chicxulub impact 66 million years ago ended the Cretaceous and eliminated ~75% of species including non-avian din
S_4_06 — Interstellar Communication — SETI, Breakthrough Listen, and the Search for Intelligence
The scientific search for extraterrestrial intelligence (SETI) has proceeded for over six decades since Frank Drake's Project Ozma (1960) first aimed a radio telescope at nearby stars, yet no confirmed signal of intellig
S_1_06 — Internet and Digital Civilization — From ARPANET to the Algorithmic Age
The internet — humanity's most transformative communication infrastructure — evolved from a U.S. military research network (ARPANET, 1969) through academic adoption, commercialization (1990s), and the World Wide Web (Ber
S_1_02 — The Singularity and Transhumanism
The Singularity hypothesis proposes that technological progress will reach a point — estimated by Ray Kurzweil at approximately 2045 — where artificial superintelligence triggers runaway growth, fundamentally and irrever
S_5_02 — Surveillance Technology — Panopticism, Mass Surveillance, and the Architecture of Control
Surveillance technology has evolved from Bentham's architectural Panopticon concept (1787) through the analog era of telephone wiretapping and photographic surveillance to the digital panopticon of the 21st century — whe
S_5_13 — Prediction Markets: Collective Intelligence and Crowd Forecasting
Prediction markets — markets where participants buy and sell contracts whose payoffs depend on the outcome of future events — aggregate dispersed information into probability estimates with remarkable accuracy, often out
S_2_07 — Neurotechnology and Cognitive Enhancement
Neurotechnology encompasses tools that interface with the nervous system to monitor, modulate, or enhance neural function. Non-invasive brain stimulation: Transcranial Magnetic Stimulation (TMS) uses magnetic pulses to s
F_1_11 — Sweet Potato Paradox — Pre-Columbian Trans-Pacific Contact Evidence
The sweet potato paradox — the presence of Ipomoea batatas (a plant of unambiguous South American origin) across Polynesia in pre-Columbian contexts — is the single most widely accepted piece of evidence for trans-Pacifi
F_1_07 — First Americans Debate — Clovis, Pre-Clovis, and Coastal Routes
The question of when and how humans first reached the Americas has been transformed in the 21st century by a series of discoveries that have demolished the long-reigning "Clovis-first" paradigm. For decades, the archaeol
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