RESEARCH BASE

Search 3,721 documents across 34 fields — every claim tier-rated by evidence

3,721 Documents 34 Sections 43,625 Citations 34,852 Keywords Indexed 4 Evidence Tiers

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.

899 results for "PER" — page 37 of 45

R_4_09 Verified Biology & Evolution

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

parasitism host-parasite coevolution Red Queen arms race Plasmodium malaria
R_4_17 Verified Biology & Evolution

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

biogeography Wallace Line Alfred Russel Wallace island biogeography continental drift Wallacea
R_4_08 Verified Biology & Evolution

R_4_08 — Echolocation and the Evolution of Sensory Systems

The evolution of sensory systems represents some of the most striking convergent solutions to ecological challenges across the animal kingdom. Echolocation — the ability to emit sound pulses and interpret returning echoe

echolocation biosonar bat dolphin toothed whale convergent evolution
R_3_08 Verified Biology & Evolution

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

speciation reproductive isolation allopatric speciation sympatric speciation peripatric speciation parapatric speciation
R_3_17 Verified Biology & Evolution

R_3_17 — Neoteny & Heterochrony: Developmental Timing in Evolution

Heterochrony — evolutionary change in the timing or rate of developmental processes — is one of the most powerful mechanisms by which organisms evolve new morphologies without requiring entirely new genetic programs. The

neoteny heterochrony paedomorphosis peramorphosis Stephen Jay Gould developmental timing
R_3_12 Verified Biology & Evolution

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

evolution of sex sexual reproduction asexual reproduction meiosis recombination Red Queen hypothesis
R_3_11 Verified Biology & Evolution

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

microevolution rapid adaptation contemporary evolution natural selection genetic drift gene flow
R_3_14 Verified Biology & Evolution

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

aging senescence evolution mutation accumulation antagonistic pleiotropy disposable soma
R_3_10 Verified Biology & Evolution

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

protein evolution molecular machine protein folding enzyme kinesin myosin
R_5_20 Verified Biology & Evolution

R_5_20 — Mass Extinction Recovery: Post-Crisis Adaptive Radiation

Life on Earth has survived at least five major mass extinctions — the "Big Five" — each eliminating 75–96% of species. Yet each catastrophe was followed by a remarkable recovery phase in which surviving lineages radiated

mass extinction recovery adaptive radiation end-permian end-cretaceous K-Pg
R_5_02 Verified Biology & Evolution

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

megafauna extinction Pleistocene extinction Quaternary extinction overkill hypothesis climate change woolly mammoth
R_5_04 Verified Biology & Evolution

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

eusociality kin selection inclusive fitness Hamilton's rule haplodiploidy superorganism
R_5_14 Verified Biology & Evolution

R_5_14 — Thermoregulation: Endothermy, Ectothermy, and Metabolic Evolution

Thermoregulation — the ability to maintain body temperature within functional limits — is a fundamental challenge of animal life, and the strategies organisms employ span a continuum from pure ectothermy (relying on envi

thermoregulation endothermy ectothermy homeothermy poikilothermy metabolism
R_5_07 Credible Biology & Evolution

R_5_07 — Ethnobotany: Plants, People, and Traditional Knowledge

Ethnobotany — the study of the relationships between plants and people across cultures and throughout history — documents how human societies have used plants for food, medicine, shelter, textiles, tools, dyes, poisons,

ethnobotany traditional plant knowledge medicinal plants indigenous knowledge Schultes economic botany
R_2_13 Verified Biology & Evolution

R_2_13 — Mammalian Radiation: Post-Cretaceous Diversification

The Cretaceous-Paleogene (K-Pg) mass extinction 66 million years ago — triggered by an asteroid impact and possibly exacerbated by Deccan Traps volcanism — eliminated the non-avian dinosaurs and opened vast ecological ni

mammalian radiation adaptive radiation Cretaceous-Paleogene extinction K-Pg boundary placental mammal marsupial
R_2_01 Verified Biology & Evolution

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

brain evolution encephalization cognitive revolution Homo sapiens neocortex language
R_2_03 Verified Biology & Evolution

R_2_03 — Neanderthal Cognition and Interbreeding

For over a century, Neanderthals were depicted as brutish, cognitively inferior "cave men" — a failed evolutionary experiment replaced by superior modern humans. This narrative has been DEMOLISHED by 21st-century genetic

Neanderthal Homo neanderthalensis hybridization interbreeding DNA genome
R_2_06 Verified Biology & Evolution

R_2_06 — Isbell Snake Detection Hypothesis

This document examines Isbell Snake Detection Hypothesis, a topic within the Biology Evolution research area. Key areas of investigation include Origin and Author, The Core Thesis, The Expanded Pulvinar. The analysis spa

Lynne Isbell snake detection theory primate vision pulvinar nucleus trichromatic vision Quan Van Le
R_2_15 Verified Biology & Evolution

R_2_15 — Neoteny and Heterochrony in Human Evolution

Heterochrony — evolutionary change in the timing or rate of developmental processes — is one of the most powerful mechanisms by which evolution generates morphological diversity without requiring new genes. [KEY FINDING]

neoteny heterochrony paedomorphosis peramorphosis developmental-timing skull-morphology
R_2_09 Credible Biology & Evolution

R_2_09 — Self-Domestication Hypothesis — Did Humans Tame Themselves?

The human self-domestication hypothesis proposes that Homo sapiens underwent a domestication process analogous to that of dogs, livestock, and Belyaev's experimentally domesticated foxes — but without an external domesti

self-domestication Brian Hare cranial globularization reduced brow ridge sexual dimorphism neural crest cells