How genes pass down

Work through real pairing odds and plan a recessive line.

Each parent gives one copy of a gene to each hatchling. For a recessive gene such as Axanthic, one known carrier paired with a gecko without it has a 50% chance to pass on a carrier. None of that pairing's hatchlings would show Axanthic.

One carrier and one without Axanthic. Each cell is one equally likely combination.
Mother ↓ Father →	+	+
x	x/+	x/+
+	+/+	+/+

When both parents are known carriers, each hatchling has a 25% chance to show Axanthic and a 50% chance to carry one copy. A visual Axanthic paired with a known carrier gives a 50% chance to show Axanthic and a 50% chance to carry it. Each egg has its own chance; a clutch is not required to follow those proportions.

Two known carriers. Each cell is one equally likely combination.
Mother ↓ Father →	x	+
x	x/x	x/+
+	x/+	+/+

A visual Axanthic and a known carrier. Each cell is one equally likely combination.
Mother ↓ Father →	x	+
x	x/x	x/+
x	x/x	x/+

In each square, x/x shows Axanthic, x/+ carries it without showing it, and +/+ has no Axanthic copy.

Read the Axanthic library sheet to see the visual goal beside these odds. For colour combinations across the same parents, read Base colour.

To work toward a visual recessive, first keep or breed a known carrier, then find a second known carrier or a visual gecko. Open Pairing, choose the female and a candidate male, and read the gene-by-gene odds before you commit. A possible carrier is less certain than a known carrier, so its outlook can change as you learn more.

A known carrier can pass Axanthic on even though the gene does not show.

Next: Morph names