Did Natural Selection Make the Dutch the World's Tallest People?
Imagine traveling to the Netherlands in 1750 and standing among crowds where the average man measured just 165 cm (5'4"). Return today, and you'd crane your neck at men averaging 183 cm (6'0")—a staggering 20 cm increase in 150 years. This radical growth spurt transformed the Dutch from Europe's shortest population to the world's tallest, sparking a scientific puzzle: Was this evolution in action, or merely environmental magic? 2 3 5
The debate cuts to the heart of how we understand human evolution. While diet and healthcare are obvious suspects, recent studies suggest natural selection—the Darwinian engine of trait propagation—might have played a role. But as we'll see, quantifying evolutionary forces reveals a cautionary tale about overstating nature's hand in our biology.
The Dutch height revolution aligns with sweeping societal changes:
In 2015, a bombshell study proposed evolution was accelerating Dutch tallness. Researchers analyzed 42,616 Dutch adults born between 1935–1967 and found:
This suggested a selective advantage: tall Dutch men were more likely to find partners, earn higher incomes, and signal health—traits appealing to mates. Their genes, propagating across cohorts, could theoretically explain the population's ascent.
But how strong was evolution's hand? Quantification would soon test this narrative.
To isolate natural selection's role, researchers mined the LifeLines Cohort—a vast database of 94,516 Dutch citizens from the northern provinces. They focused on individuals who completed reproduction (ages 45+), excluding immigrants to control for ancestry. Key steps included:
Data confirmed correlations between stature and reproductive success:
| Height Quartile | Avg. Children | Child Survival Rate |
|---|---|---|
| Shortest 25% | 2.12 | 94.1% |
| 25–50% | 2.25 | 95.0% |
| 50–75% | 2.31 | 95.8% |
| Tallest 25% | 2.41 | 96.3% |
| Source: LifeLines Cohort analysis 3 | ||
Despite statistical significance, the magnitude of selection was minuscule:
To test the "natural selection hypothesis," evolutionary biologist Gert Stulp simulated Dutch height trends:
If selection alone caused the 20 cm gain, the tallest men (top 2%) would need 8× more children than average—a reproductive skew never observed.
Restricting reproduction to the tallest 37% of people still couldn't explain the speed of change.
Adding environmental factors (diet, healthcare) perfectly recreated real-world data .
| Factor | Estimated Contribution | Mechanism |
|---|---|---|
| Nutrition (dairy, protein) | ~60–70% | Bone development during growth |
| Healthcare/Wealth | ~25–35% | Reduced disease and stress |
| Natural selection | <2% (0.07–0.36 cm) | Slight reproductive edge for tall |
| Source: Stulp et al. simulations | ||
These models highlight phenotypic plasticity—the body's ability to alter development in response to environments. Dutch children, fueled by post-war prosperity, reached genetic potential stunted in prior generations. Genes didn't change; their expression did.
Key methods in genetic epidemiology clarify such debates:
| Tool/Concept | Function | Example in Height Research |
|---|---|---|
| GWAS | Scans genomes for variants linked to traits | Identifies 180+ height-associated genes in Dutch cohorts 1 4 |
| Mendelian Randomization | Tests causality using genetic proxies | Confirms dairy intake → height gain, not vice versa 1 |
| Heritability Estimates | Quantifies trait's genetic dependency | Height is 80% heritable—but environment unlocks it 4 |
| PLINK | Software for genetic QC and association tests | Analyzed LifeLines genotype-phenotype links 1 |
| MR-Base | Database for MR analysis | Clarified diet's causal role in Dutch stature 1 |
Recent data reveals a twist: Dutch born in 2001 are 1–1.4 cm shorter than 1980s cohorts. Immigration plays a role, but even native Dutch show declines. Researchers blame:
This reversal underscores environmental primacy. If natural selection drove tallness, it wouldn't vanish in one generation.
The Dutch height story teaches three lessons:
Yes, taller Dutch men had slightly more children. But simulations show environment catalyzed 98% of their growth spurt. It's a potent reminder that evolution operates on geological timescales—while cheeseburgers, milk subsidies, and public health can reshape a population in a century. As the Dutch shrink, we're witnessing not evolution's retreat, but the fading of a golden environmental age.
The Dutch didn't evolve to be tall; they thrived in ways that made their genes shine.