Genetics refers to the study of genes, heredity, and genetic variation. In cPNI, the critical insight is that human genetics change extraordinarily slowly (0.1% per million years) while our environment has changed radically in just 250 years, creating evolutionary mismatch as the root cause of modern chronic disease.
Humans have 21,787 genes total, of which only 21 are truly unique to modern Homo sapiens. The vast majority of our genome evolved under conditions vastly different from modernity: hunter-gatherer lifestyle, intermittent food availability, high pathogen exposure, intense physical demands, strong social bonds, and natural circadian rhythms. Genetic variation occurs through mutations (random DNA changes), polymorphisms (common variants like SNPs), and selection pressures. However, genetic change requires thousands of generations—our genome is essentially identical to our Paleolithic ancestors 50,000 years ago, yet we live in completely different environmental context.
Understanding genetics in cPNI means recognizing that most chronic diseases are NOT purely genetic (which would be immutable) but reflect gene-environment mismatch. Autoimmune diseases, obesity, diabetes, depression, and most modern pathologies are significantly epigenetic (environmentally modulated) rather than genetically determined. This is profoundly empowering: while we cannot change genes, we can modify epigenetic expression through lifestyle interventions (diet, movement, stress, sleep, relationships). Genetic testing (SNPs for MTHFR, COMT, 5-HTTLPR, etc.) reveals vulnerabilities but does NOT determine destiny—it identifies where environmental intervention is most critical.
- Human genetics change at 0.1% per 1,000,000 years
- Only 21 genes are unique to modern Homo sapiens out of 21,787 total
- Environment has changed radically in just 250 years creating mismatch
- Most chronic diseases are epigenetic (environmentally modulated) not purely genetic
- Autoimmune conditions emerge after triggers despite genetic predisposition
- SNPs (single nucleotide polymorphisms) reveal vulnerabilities not destiny
- Genetic variation maintained through balancing selection and heterozygote advantage
- Founder effects and genetic drift create population-specific variants
- Gene-environment interaction determines phenotype and disease risk
- Lifestyle interventions can overcome genetic vulnerabilities through epigenetic modulation
- epigenetics — epigenetic modifications allow environmental factors to modulate genetic expression without changing DNA sequence
- evolutionary mismatch — evolutionary mismatch occurs when slow genetic change cannot keep pace with rapid environmental change
- SNPs — single nucleotide polymorphisms are common genetic variants that create individual vulnerability patterns
- MTHFR — MTHFR polymorphisms exemplify how genetic variants create metabolic vulnerabilities requiring environmental compensation
- COMT — COMT variants demonstrate genetic influence on neurotransmitter metabolism and stress response
- 5-HTTLPR — 5-HTTLPR polymorphism shows genetic modulation of serotonin transport affecting mood and stress vulnerability
- autoimmune diseases — autoimmune diseases have genetic predispositions but require environmental triggers (epigenetic) to manifest
- hunter-farmer — hunter vs farmer metabolic genetics create different vulnerability patterns to modern diet
- birth weight — birth weight reflects epigenetic programming responding to prenatal environment, not just genetics
- lactase persistence — lactase persistence gene is recent adaptation showing gene-culture coevolution
- AMY1 gene copy number — amylase gene copies vary by ancestral diet showing genetic adaptation to carbohydrate exposure
- filaggrin — filaggrin gene variants are genetic risk for atopic march but environment determines expression
- HLA antigens — HLA genetic diversity evolved for pathogen defense but creates autoimmune susceptibility in mismatch
- evolution — evolution through natural selection shapes genetic variation over thousands of generations
- mutation — mutations introduce new genetic variation but most are neutral or deleterious
- founder effects — founder effects create population-specific genetic patterns from small ancestral groups
- balancing selection — balancing selection maintains genetic polymorphisms when heterozygotes have advantage
- sexual selection — sexual selection drives genetic evolution of traits beyond survival fitness
- phenotype — phenotype results from genetic blueprint interacting with environmental context
- DNA methylation — DNA methylation is epigenetic mechanism that modulates genetic expression without changing sequence