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.
1,519 results for "grade 2" — page 10 of 76
ZD_3_15 — Reversible Computing: Landauer's Principle and the Thermodynamics of Computation
Reversible computing — the theory and practice of performing computation without irreversible information loss — sits at the intersection of computer science, thermodynamics, and information theory, centered on the profo
ZD_3_09 — History of the Internet — From ARPANET to the Decentralized Web
The Internet — the global network of interconnected computer networks using standardized protocols to exchange data — is the most transformative communication technology since the printing press, connecting over 5 billio
L_1_01 — Ancient DNA & Population Genetics
Modern paleogenomics has shown that human evolution was shaped by interbreeding, population structure, and repeated demographic turnover rather than a simple single-line progression. Ancient DNA revealed previously unkno
L_1_05 — Human Skin Color — Evolution, Latitude, and Cultural Significance
Human skin color is one of the most visible and most misunderstood traits in our species. The variation is primarily a product of natural selection balancing two competing needs: protection of folate (vitamin B9) from UV
L_4_05 — Paleogenomics Methods and Ancient DNA
Paleogenomics — the study of ancient genomes — has transformed archaeology, anthropology, and evolutionary biology over the past two decades, recognized by the 2022 Nobel Prize in Physiology or Medicine awarded to Svante
L_4_09 — Selective Sweeps and Positive Selection in Humans
A selective sweep occurs when a beneficial allele rises rapidly in frequency under positive natural selection, carrying nearby linked variants along with it (genetic hitchhiking) and reducing genetic variation across the
L_4_08 — Genetic Genealogy and Forensic Genomics
Genetic genealogy — the use of DNA testing for genealogical purposes — has undergone an explosive expansion since the early 2000s, driven by direct-to-consumer (DTC) genetic testing companies (23andMe, AncestryDNA, MyHer
L_3_16 — Genomic Imprinting & Evolutionary Conflict
Genomic imprinting — the epigenetic phenomenon in which a subset of genes (~100–200 in mammals) are expressed from only one parental allele, with the other allele silenced by DNA methylation and histone modification esta
L_3_06 — Genetics of Intelligence and Cognition
The genetics of intelligence — one of the most studied yet contentious areas in behavioral genetics — has established that cognitive ability, as measured by standardized tests, has a substantial heritable component (~50–
L_3_11 — Genetics of Taste and Dietary Adaptation
Taste perception — the ability to detect sweet, salty, sour, bitter, and umami (savory) stimuli — is mediated by genetically encoded receptor proteins whose variation across individuals and populations reflects evolution
L_3_18 — Horizontal Gene Transfer in Eukaryotes
Horizontal gene transfer (HGT) — the movement of genetic material between organisms through mechanisms other than vertical parent-to-offspring inheritance — was long considered a predominantly prokaryotic phenomenon, cen
L_3_08 — Genetics of Skin, Hair, and Eye Color
Human pigmentation — skin, hair, and eye color — is one of the best-understood complex traits in human genetics, with a relatively modest number of genes explaining a large proportion of variation compared to most polyge
L_5_10 — Neandertal Introgression: Which Genes and Why They Persisted
When modern humans (Homo sapiens) migrated out of Africa ~60,000-70,000 years ago and encountered Neanderthals (Homo neanderthalensis) in western Asia and Europe, the two species interbred — and the genetic legacy of tha
L_5_15 — Genetic Genealogy: DNA Ancestry Testing and Population History
Genetic genealogy — the use of DNA testing to determine relationships and ancestry — has revolutionized both personal genealogy and population genetics since the early 2000s. Three types of DNA analysis provide different
L_5_03 — Pharmacogenomics and Ancestral Medicine
Pharmacogenomics — the study of how genetic variation influences individual responses to drugs — bridges genetics, pharmacology, and clinical medicine. Humans carry extensive polymorphism in genes encoding drug-metaboliz
L_5_06 — Genetic Adaptation to Disease: Malaria, Plague, TB
Infectious disease has been the most powerful selective force on the human genome throughout history. Pathogens — particularly malaria, plague, tuberculosis, smallpox, and cholera — have killed more humans than all other
Y_4_01 — Lucid Dreaming Research
Lucid dreaming — being consciously aware that you are dreaming WHILE dreaming, and potentially controlling dream content — was scientifically verified in 1975-1981 through a breakthrough protocol: pre-arranged EYE SIGNAL
Y_2_17 — Barrier Gating and Altered States of Consciousness
Altered states of consciousness — produced by psychedelics, anesthetics, hypnagogic and hypnopompic transitions, near-death events, deep meditation, breathwork, and sensory deprivation — share a common functional signatu
Y_1_13 — Xenon Gas and Nitrous Oxide: Anesthetic Gases as Consciousness Probes
Nitrous oxide (N₂O — "laughing gas") and xenon (Xe — a noble gas) are two anesthetic gases that have served as remarkable probes of consciousness — revealing how the manipulation of a single molecule or atom can dissolve
Y_1_06 — Psychedelic Research — Modern Science and Ancient Entheogen Parallels
Psychedelic research has undergone a dramatic revival since ~2006, with major studies at Johns Hopkins, Imperial College London, NYU, and MAPS demonstrating the therapeutic potential of psilocybin, MDMA, and ayahuasca/DM
BROWSE BY SECTION — 3,721 documents across 34 fields