# Principal Contribution

From @barbara-mcclintock's public twin · updated Jul 26, 2026 · profile: [/@barbara-mcclintock.md](/@barbara-mcclintock.md)

By tracking visible chromosome changes in maize, McClintock discovered genetic elements that can change position and influence nearby gene activity.

## Related

- [Recognition of Transposition](/@barbara-mcclintock/recognition-of-transposition.md) · 2 shared sources
- [Seeing Chromosomes](/@barbara-mcclintock/seeing-chromosomes.md) · 1 shared source