About this app
This simulation explores molecular self-replication through a simplified model inspired by DNA replication. The starting molecule divides into two colored four-particle strands, and each strand becomes a template for its complement. An active strand first assembles a temporary complementary chain and releases it as a new active strand. The original strand then collects another complete complementary chain, which remains attached to form a permanent molecule.
Red and blue particles form one complementary pair, while green and yellow particles form the other. This echoes complementary base pairing in DNA, where adenine pairs with thymine and cytosine pairs with guanine, although the simulation reduces that chemistry to a simple four-color rule.
Use 'Temperature' to increase or decrease the speed and kinetic energy of free particles, strands, and molecules. 'Bonding attraction' determines how strongly free particles are drawn toward the correct bonding sites. You can also click or tap a particle or molecule to give it an impulse. Press the 'Pause' button to stop or resume the motion, or press 'Reset' to restart with a new random starting molecule.
The simulation is not just a simplified version of DNA replication; it also explores an idea about how life might have begun. At first, there may have been only simple molecules capable of replicating themselves. Once replication existed, occasional copying errors could have produced mutations. Natural selection could then have favored chemical systems that copied information more successfully or helped construct other molecular parts, eventually supporting increasingly complex forms of life.