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57 results for "balancing selection" — page 1 of 3
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
Z_2_11 — Genetics of Immunity and MHC Diversity
The major histocompatibility complex (MHC) — known as the human leukocyte antigen (HLA) system in humans — is the most polymorphic gene region in the human genome, encoding cell-surface glycoproteins essential for adapti
Z_2_07 — Genetics of Disease Resistance
Infectious disease has been the most powerful selective force shaping the human genome, leaving signatures across thousands of loci. The best-understood example is sickle cell disease (HbS, Glu6Val in HBB): heterozygous
Z_2_01 — HLA System & Archaic Immune Inheritance
The Human Leukocyte Antigen (HLA) system is the most polymorphic region of the human genome, encoding cell-surface proteins critical to adaptive immune function. Located on chromosome 6p21.3, the Major Histocompatibility
L_3_09 — HLA Diversity and Immune System Evolution
The Human Leukocyte Antigen (HLA) system — the human version of the Major Histocompatibility Complex (MHC) found in all jawed vertebrates — is the most polymorphic gene region in the entire human genome. Located on chrom
ZB_1_13 — Sexual Selection and Mate Choice
Sexual selection — first articulated by Darwin (1871) in The Descent of Man, and Selection in Relation to Sex — is the evolutionary process by which traits that increase mating success are favored, even when they decreas
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
R_3_04 — Sexual Selection — Mate Choice and Evolutionary Aesthetics
Sexual selection, first articulated by Charles Darwin in The Descent of Man, and Selection in Relation to Sex (1871), explains traits that enhance mating success rather than survival — from the peacock's extravagant tail
L_3_12 — Genetics of Pigmentation: Skin, Hair, and Eye Color Evolution
Human pigmentation — the variation in skin, hair, and eye color across populations — is one of the most visible and best-understood examples of natural selection in our species. Pigmentation is determined primarily by th
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
H_3_16 — The Classics Canon: What Was Selected, What Was Lost
Of the vast literary output of the ancient Greek and Roman world — estimated at tens of thousands of texts — only a tiny fraction survives. The ancient classics canon as we know it is not a representative sample of ancie
P_2_13 — Philosophy of Biology: Teleology, Species Concepts, and Function
The philosophy of biology examines the conceptual foundations, explanatory structures, and ontological commitments of the biological sciences — asking questions that biology itself presupposes but does not typically addr
R_2_11 — Convergent Evolution: Parallel Solutions Across Lineages
Convergent evolution — the independent origin of similar features in unrelated lineages — is one of the most striking patterns in the history of life, suggesting that natural selection repeatedly discovers the same "solu
U_4_03 — Cultural Evolution — Dual Inheritance and Cumulative Culture
Cultural evolution theory applies Darwinian principles — variation, selection, inheritance — to the transmission and transformation of cultural information (beliefs, technologies, norms, institutions). The dual inheritan
ZH_5_13 — Archaeoastronomical Controversies: Precision Debates and Methodological Limits
Archaeoastronomy — the study of how past cultures understood and used celestial phenomena — has been marked by recurring methodological controversies since its modern founding in the 1960s. The central problem: when an a
Z_3_12 — Genetics of Alcohol Metabolism
The genetics of alcohol metabolism provides one of the clearest examples of how specific genetic variants influence behavior and disease risk at a population scale. Ethanol is metabolized primarily through a two-step oxi
Z_3_01 — Genetics of Brain Development — ASPM, Microcephalin, HAR1
The human brain is approximately three times larger than expected for a primate of our body size, with a vastly expanded cerebral cortex containing ~86 billion neurons. Identifying the genetic basis for this extraordinar
Q_1_14 — Vacuum Energy and the Cosmological Constant Problem
The cosmological constant problem is widely regarded as the most severe fine-tuning problem in all of physics. Quantum field theory predicts that the vacuum of spacetime is not empty but seethes with zero-point fluctuati
Q_1_01 — The Anthropic Principle & Fine-Tuning of the Universe
The universe appears to be astonishingly fine-tuned for the existence of complex life. Alter the cosmological constant by 1 part in 10¹²⁰, or the strong nuclear force by 0.5%, or the ratio of electromagnetic to gravitati
ZB_1_02 — Social Insects — Superorganisms and Collective Intelligence
Social insects — ants, bees, wasps, and termites — represent one of evolution's most spectacular innovations: the subordination of individual reproduction to colony-level organization, producing "superorganisms" capable
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