Planet Zoo 2 Genetics and Inbreeding: How Genes Work

The four genes

Every animal has its own DNA and inherits its genes from both parents, so young can turn out better or worse than either parent. The genes come in two kinds.

Additive genes: both parents with good genes reinforce each other. Diversity genes: parents that are different from each other; inbreeding makes double pairs more likely. Breeding is covered step by step in our Planet Zoo 2 breeding guide, with each animal's mating season and gestation.

What Vitality means in Planet Zoo 2

Vitality is one of the four genes on an animal's Genetics tab and one of the two additive genes, with Longevity. It is a quality you build up by breeding: its 12 letters count for more the more of them are A or B, and when both parents carry many A and B letters, their young can end up with higher Vitality than either.

• To raise it: open Compare Mates in the Genetics tab and choose the partner whose Vitality letters hold the most A and B. Type both animals' letters into the gene reader above to compare them side by side.
• Inbreeding: Frontier names Fertility and Immunity as the genes that inbreeding wears down. Vitality improves by selection instead, so pairing two strong relatives does not fix weak Fertility.

How to read the gene letters

The Genealogy screen of an animal's Info Panel shows its parents, siblings, mates and offspring together with their Genetics, so you can follow a gene through a family. Each gene is six pairs of the letters A, B, C and D. A young animal takes one set of letters from each parent to form its own genes, and there is a small chance that a single letter mutates into another.

• Vitality and Longevity: count the A and B letters. The more there are, the better the gene, so breed animals with many A and B letters to raise them.
• Fertility and Immunity: count the double pairs, such as AA, BB, CC or DD. The fewer there are, the better the gene.

What inbreeding does in Planet Zoo 2

Genes improve when the genetic information from the two parents is different; otherwise traits such as Fertility degrade, and that is what tends to happen with inbreeding. Inbred young get double letter pairs more often, so over successive generations inbreeding lowers Fertility and Immunity. Animals with weak Fertility breed less easily, and Immunity is part of how fast light injuries heal.

How to avoid inbreeding

1. Open the Genealogy screen of the animal's Info Panel: it shows parents, siblings, mates and offspring, with their Genetics.
2. Open Compare Mates in the Genetics tab: it shows the likely genes of the young of each possible pair.
3. Pair animals whose genes are different from each other; genes improve with more genetic diversity.
4. Adopt animals with a high Genetic Rating from the Trade Centre and breed them into your group.
5. Keep the pair's welfare high and Research the species to unlock fertility boosts.
6. Stop unwanted pairs with contraception or by keeping them in separate habitats.

A healthy, varied group matters most when you breed animals to release: the release steps are on our Planet Zoo 2 Wildlife Reserves guide, and the release groups finder shows which group types each animal can be released as.

Shoals have no genetics

Shoals have no Genetics to manage, though some species, such as Koi, have colour morphs. A shoal grows each mating season as one group and splits once it is full, so the gene reader is only for animals you keep one by one.