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.

2,646 results for "SI second" — page 99 of 133

L_2_03 Verified Genetics & Origins

L_2_03 — Ancient African Genetics

Africa harbors the greatest human genetic diversity on Earth — a direct consequence of being the continent of human origin, where populations have accumulated genetic variation for ~300,000+ years. Modern African populat

African genetics ancient African DNA African population history Bantu expansion Khoisan genetics deep population structure
L_2_14 Verified Genetics & Origins

L_2_14 — Sex-Biased Admixture: Patrilocal vs. Matrilocal Migration

One of the most powerful revelations from ancient and modern DNA studies is that human migration, conquest, and admixture are almost never sex-neutral — they are systematically biased toward one sex or the other, produci

sex-biased admixture patrilocality matrilocality Y chromosome mtDNA X chromosome
L_2_05 Verified Genetics & Origins

L_2_05 — Americas Peopling Genetics

The peopling of the Americas is one of the clearest cases where ancient DNA and archaeology have converged to overturn an older narrative. The core model now favored by genetics is that the main ancestry of Indigenous Am

Americas peopling Beringia Clovis pre-Clovis Native American genetics mtDNA haplogroups
L_2_04 Verified Genetics & Origins

L_2_04 — Oceanian Genetics and Pacific Migration

The human settlement of Oceania represents the last major expansion of Homo sapiens across the globe, and the most remarkable feat of maritime exploration in human history. It occurred in two major phases separated by ~4

Oceanian genetics Pacific migration Lapita Austronesian expansion Polynesia Melanesia
L_2_09 Verified Genetics & Origins

L_2_09 — Genetic History of the Americas: Clovis to Contact

The genetic history of the Americas — from the initial peopling of the New World to the devastating population collapse after European contact — is one of the most intensively studied and rapidly evolving areas of paleog

Americas Native American Beringia Clovis pre-Clovis Anzick
L_2_18 Verified Genetics & Origins

L_2_18 — Archaic Admixture in Africa (Ghost Populations)

While Neanderthal and Denisovan admixture in non-African populations has been well-documented since Svante Pääbo's landmark 2010 Neanderthal genome paper, evidence for archaic admixture within Africa represents a more re

archaic admixture ghost population African genetics ancient DNA introgression archaic hominin
L_3_16 Verified Genetics & Origins

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

genomic imprinting parent-of-origin expression epigenetics kinship theory parental conflict IGF2
L_3_06 Credible Genetics & Origins

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–

intelligence genetics cognitive ability IQ heritability GWAS intelligence polygenic score educational attainment
L_3_17 Verified Genetics & Origins

L_3_17 — Endogenous Retroviruses (HERVs) in the Human Genome

Human endogenous retroviruses (HERVs) — remnants of ancient retroviral infections that integrated into the germline DNA of human ancestors and have been vertically transmitted through the host genome for millions of year

endogenous retroviruses HERVs HERV-K HERV-W syncytin retroviral integration
L_3_13 Verified Genetics & Origins

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

human accelerated regions HARs HAR1 HACNS1 conserved noncoding enhancer
L_3_05 Verified Genetics & Origins

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

blood type ABO system Rh factor Karl Landsteiner blood transfusion blood group antigens
L_3_18 Verified Genetics & Origins

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

horizontal gene transfer lateral gene transfer HGT LGT eukaryotes introgression
L_3_02 Credible Genetics & Origins

L_3_02 — Caduceus / Twin-Serpent / DNA Symbolism

This document surveys the widespread twin-serpent-on-axis motif and compares it with the modern DNA double helix. The iconography itself is real and historically well documented, and the molecular structure of DNA is lik

caduceus Rod of Asclepius Ningishzida Hermes kerykeion Fuxi
L_3_08 Verified Genetics & Origins

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

pigmentation genetics melanin eumelanin pheomelanin MC1R OCA2
L_3_07 Credible Genetics & Origins

L_3_07 — Behavioral Genetics: Nature and Nurture

Behavioral genetics — the scientific study of how genetic and environmental factors contribute to individual differences in behavior — has transformed our understanding of human psychology over the past half-century. Thr

behavioral genetics nature nurture twin study heritability adoption study gene-environment interaction
L_5_01 Verified Genetics & Origins

L_5_01 — Human Microbiome and Co-Evolution

The human microbiome — the aggregate community of microorganisms (bacteria, archaea, fungi, viruses, protists) living on and within the human body — comprises roughly 38 trillion microbial cells (Sender et al., 2016, Cel

microbiome gut bacteria metagenomics holobiont dysbiosis Firmicutes
L_5_06 Verified Genetics & Origins

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

natural selection disease adaptation malaria sickle cell G6PD Duffy antigen
L_5_08 Verified Genetics & Origins

L_5_08 — Ancient DNA from Sediments: Cave Dirt Genomics

One of the most revolutionary methodological advances in ancient DNA (aDNA) research has been the recovery of hominin DNA directly from cave sediments — without any bones or teeth. This technique, pioneered by Matthias M

sediment DNA environmental DNA eDNA cave sediment ancient DNA metagenomic
L_5_09 Verified Genetics & Origins

L_5_09 — Human Microbiome Co-Evolution: Ancient Gut Companions

The human microbiome — the trillions of bacteria, archaea, fungi, and viruses that inhabit our bodies, particularly the gastrointestinal tract — is not merely a passive inhabitant but a co-evolved partner that has shaped

microbiome gut bacteria co-evolution Helicobacter pylori human migration paleomicrobiology
L_5_04 Verified Genetics & Origins

L_5_04 — Ancient Microbiome and Paleomicrobiology

Paleomicrobiology — the study of ancient microorganisms through the application of molecular techniques (ancient DNA extraction, metagenomics, proteomics) to archaeological and paleontological material — has revolutioniz

microbiome paleomicrobiology ancient DNA aDNA dental calculus coprolite