[Verse 1] Count alleles like coins tossed in the wind, Hardy and Weinberg drew the calm within— p squared, two p q, q squared, the trio holds still, till drift comes shaking the frequency's will. Wright-Fisher spins a wheel of finite seed, Moran swaps one soul at a time, and we proceed, effective size N-e, the population's true heart, smaller than the census count, drift plays its part. [Chorus] Count the alleles, p and q entwined, Pi and Watterson's Theta, diversity defined, Tajima's D tells if the tree runs cold or hot, drift or selection—know which one, and which is not. [Verse 2] Coalescent traces lineages back through time, two branches close and merge—that's the coalescent rhyme. Site frequency spectrum, a histogram of age, rare mutations young, the common ones the sage. Pi counts the pairwise differences we find, Theta Watterson counts segregating sites combined, when the two disagree, Tajima's D will confess a bottleneck's shadow or a sweep's caress. D-prime and r-squared measure linkage's tight embrace, distance breaks the bond, the haplotype block loses face. [Chorus] [Verse 3] FST splits the globe, populations drawn apart, PCA plots the drift map on a genomic chart, ADMIXTURE paints ancestry in colored bars of proof, D-statistics whisper if ghosts once shared a roof. dN over dS, the ratio of change, McDonald-Kreitman sorts the neutral from the strange, iHS and XP-EHH hunt the sweep's long tail, background selection thins the diversity sail. [Verse 4] PSMC reads coalescence deep in the past, msprime and SLiM simulate what bone can't forecast, tsinfer and Relate rebuild the ancestral graph entire, Jukes-Cantor, Kimura, HKY, GTR plus gamma's fire. Maximum likelihood and Bayesian trees compete, bootstrap the branches, ask if they'd survive repeat, gene trees dodge species trees when lineages sort askew, incomplete lineage sorting muddies who begat who. Synteny and orthology map the shared blueprint, phyloP and phastCons score what conservation meant, ancient DNA, brittle strands of frozen kin, whispering how populations wandered, and where they've been. [Verse 5] Quantitative traits bow to polygenic score, GWAS hunts the variants hiding at the core, heritability splits the nature from the nurture's claim, epistasis tangles credit, no locus wins alone the fame. Recombination shuffles the deck with every generation's turn, hotspots mark the places where the chromosomes churn, mutation-selection balance keeps the rare disease alive, purifying selection prunes what can't survive. [Bridge] Every genome's a manuscript of drift and design, copied errors, copied loves, copied down the line, we read the letters, count the ghosts inside the tree, the coalescent hums the oldest melody. [Chorus] [Outro] p squared, two pq, q squared—say it till it's true, Pi and Watterson's Theta, Tajima's D too, FST, PCA, the sweep and the clock, population genomics—read it in the rock.
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