A birth
Two parents, one random seed, one child. Below, the whole thing happens in front of you, byte by byte, with real parents from the population. Only the seed is different each time you draw.
Two genomes in, one genome out
Each little square is one locus. A moeba has two rows of them, one from each parent. The child’s first row is read along the first parent, the second row along the second parent, and every now and then the reading switches from one of that parent’s rows to the other. It plays on its own; pause it and step through one locus at a time, or point at a square to read it. The seed is real and so is the arithmetic: the same seed always gives the same child.
Why families have looks
Loci that sit next to each other in a row tend to be read together, because a switch is rare (24 chances in 256 at each step). The body loci travel as a block, the colour loci as another. So a child often has one parent’s build and the other’s colouring, rather than a random mix of everything. The four blocks are the four labelled groups above.
Then mutation
With the two rows read, the same random stream continues. First the pathways: rules like “if this row has allele A here, and the rest of the genome allows it, then with a small chance it becomes B”. Pathways are the only way some alleles ever appear; no founder has them, and they fire rarely. Then drift: each numeric locus, on each copy, has about a 2% chance to move one step. With 22 numeric loci in two copies, about six births in ten carry at least one such step somewhere — usually too small to see, since the body follows both copies together. A new variant from a pathway is much rarer. In the picture, a mutated square has a dot.
What the parents must satisfy
- Both issued by the Xahmoeba issuer, and of the same genetic model.
- Not the same moeba, not parent and child, not full siblings. Half-siblings may breed.
- Both mature: one minute past the moment their own randomness was fixed, on the ledger’s clock. Founders are mature from birth.
- Both with fertility left. Every moeba is born with five births and spends one per child, as either parent.
- Neither already reserved by another birth in progress.
- The requester keeps one of them, and either keeps the other or is covered by its standing permission at the price paid.
The lab above shows the issuer’s answer when a pair would be refused.
Eight children from the same two parents
Each card is the child the rules would produce from a different random seed. On the ledger only one seed happens, and nobody gets to pick which. A coloured mark means that draw had a mutation.