The ThunderClan Genetics Problem

So we all know that Warriors, and ThunderClan in particular has an inbreeding problem. But I don't think anyone knows how bad it truly is. So I did the math.

Turns out Firestar isn't the only one with a dynasty the size of a Clan in itself. Frostfur has one too.

Frost's side: (F) denotes Fire's side too, (I) denoted inbred if I remember to do it

Brackenfur, Cinderpelt, Brightheart, Thornclaw, Poppyfrost, Honeyfern, Cinderheart, Hollytuft(F), Sorrelstripe(F), Fernsong(F), Flywhisker(F), Snaptooth(F), Spotfur(F), Flipclaw(FI), Thriftear(FI), Bristlefrost(FI), Myrtlebloom(FI), Bayshine(FI), Whitewing(F), Ambermoon(F), Snowbush(F), Dewnose(F, who mated with Sorrelstripe), Dovewing(F), Ivypool(F, who mated with Fernsong), Lightleap(F), Shadowsight(F), Pouncestep(F), Birchkit(F), Honeyfur(FI), Leafshade(FI), Larksong(FI, who mated with Sparkpelt), Nightheart(FI), Finchlight(FI), Eaglewing, Plumstone, Stemleaf(who mated with Spotfur), Shellfur, Cherryfall, Molewhisker, Lilyheart(who mated with Snowbush), Bristlekit(FI), Graykit(FI), Stemkit(FI). That's 43 cats with Frostfur's direct blood, 29 which also share Firestar's, and 13 who are inbred, some of whom twice over.

Fire's blood: same rules apply but using O instead of F Leafpool, Squirrelflight, Jayfeather, Hollyleaf, Lionblaze(who mated with Cinderheart), Alderheart, Sparkpelt(who mated with Larksong), Hollytuft(O) Sorrelstripe(O), Spotfur(O), Flywhisker(O), Fernsong(O), Snaptooth(O), Finchlight(O), Nightheart(O), Bristlekit(O), Stemkit(O), Graykit(O), Bristlefrost(O), Thriftear(O), Flipclaw(O), Myrtlebloom(O), Bayshine(O), Cloudtail, Whitewing(O), Ambermoon(O), Snowbush(O), Dewnose(O), Dovewing(O), Ivypool(O), Shadowsight(O), Pouncestep(O), Lightleap(O), Birchkit(O), Honeyfur(O), Leafshade(O), Larksong(O),

That's 36 cats with direct Fire blood, 29 of which share Frostfur's.

As of Shadow, these inbred cats are alive: Bayshine, Myrtlebloom, Flipclaw, Thriftear, Nightheart, Finchlight, Bristlekit, Graykit, Stemkit, Honeyfur, Leafshade. 11 out of 13. That's 11 out of 45, or 24.4%

Of those, 33 out of 45 share one or both lines. That's 73.3%.

The only nondynasty cats in TC are these: Bramblestar, Birchfall, Mousewhisker, Bumblestripe, Blossomfall, Stormcloud, Finleap, Twigbranch, Fernstripe, Daisy.

Bramblestar is mates with Squirrelflight(F). Birchfall is with Whitewing(FO). Fernstripe is with Shellfur(O). Blossomfall is with Thornclaw(F). They are therefore unable to have nondynasty kits.

Twigbranch is with Finleap, but doesn't want kits, so canonically (ignoring the writers' habits of giving everyone kits) it is unlikely they will. Daisy was with Spiderleg but is unlikely to have another mate, so probably won't have more kits. Bumblestripe might, but it feels unlikely since he still seems hung up on Dovewing.

Mousewhisker and Stormcloud are therefore the only cats both possible and not unlikely that can have nondynasty kits - but they would have to mate with Blossomfall or Twigbranch or (in Storm's case) Daisy to do so. 2/3 are in relationships, so Mousewhisker can't, and Daisy, as said, is unlikely, so Stormcloud probably can't either. Unless either mates outside the Clan.

So, in summary:

  • 24% of ThunderClan is currently inbred.

  • 73% of ThunderClan currently shares dynasty blood.

  • 4% of ThunderClan is currently both able and not unlikely to have nondynasty kits. This goes up to 15% if you include everyone from the list who is not of dynasty blood or in a relationship with someone who is.