Biomorphs are virtual creatures devised by Richard Dawkins in his 1986 book The Blind Watchmaker as a way to visualize the power of evolution. By making tiny changes visible across generations, they demonstrate how complex forms can emerge from simple rules and cumulative selection.

How It Works

In this simulation there are 9 biomorphs: 1 parent in the center and its 8 children surrounding it. Each child's genes are identical to the parent's except for a single random mutation that slightly changes its appearance. Click any child to make it the parent of the next generation, and repeat the process to watch the biomorphs evolve over time.

If you want to guide your biomorphs toward a goal, pick a simple animal in your head ("I want to evolve a lobster") and keep choosing the child that most closely resembles that objective.

The Genes

The appearance of each biomorph is determined by 9 genes:

• Genes 1-3 influence its width
• Genes 4-8 influence its height
• Gene 9 influences its branching depth

You can directly modify the parent's genes by clicking the DNA icon and adjusting the sliders. These 9 genes can generate more than 118 billion different biomorphs. Humans, for comparison, have about 20,000 to 25,000 protein-coding genes.

Artificial vs. Natural Selection

Because you choose which child survives, biomorphs are an example of artificial selection, similar to how humans have guided dog evolution over thousands of years. In nature, evolution works through natural selection: organisms best suited to their environment are the ones most likely to survive and pass on their genes.

Why It Matters

The gradual change in each generation serves as a simple model of biological evolution. Each biomorph is nearly identical to its parent, but after many generations the appearance can diverge wildly from the original. Biological evolution works the same way, just on a much longer timescale. You closely resemble your parents, and they closely resemble theirs, but tens of thousands of generations back your distant ancestors would bear only a slight resemblance to you.

The key insight is that evolution doesn't need a designer. Small, random variations filtered through selection, whether artificial or natural, are enough to produce an astonishing diversity of forms. Dawkins created biomorphs to make this idea tangible and interactive, and they remain one of the most intuitive demonstrations of how cumulative selection works.

Originally published May 28, 2014