The first sacrifice

I. Why aren’t fish dissolving into separate cells after death?

Lets do decision theory: for each single cell, the choice matrix is: Stay attached: 0% chance of survival, guaranteed death by starvation or predation Roam away: some minuscule chance of living as a lineage of unicellular plankton

“They”

Ii.

Your house is full of trash.

That’s an easy problem to solve: you have a mop and a bucket. There’s a second bigger problem though: you’re also lazy.

Luckily youre a replicator. You can spawn a clone of yourself and tell it to do the job you dont want to do.

Naturally, your clone also gets your laziness. And your replication ability. It spawns its own clone and now both of them tell YOU to do the cleaning job.

You spawn two clones to regain the advantage.

Soon after, your house is drowning not only in trash, but also in clones.

Iii.

You are an unicellular organism in an overpopulated lake.

Luckily theres a second, pristine lake nearby. But its separated by a small patch of land you can’t cross.

You got an idea: spawn a copy! You can get on top of your copy, tell it to divide vertically ten times, and then make the stalk fall in the direction of the new lake, vaulting you over the land bridge. The stalk will perish, but you will carry their legacy.

You spawn a copy, but it refuses to get under you. Its telling YOU to get under it and sacrifice yourself to let it into the new lake. Its telling YOU to perish, and IT will carry your legacy. Thats a terrible deal!

Its clear that the plan will only work if both you and your copy have an ounce of selflessness.

But didnt dawkins teach us that genes are selfish? Sure, theres a kinship exception: “i would give my life for two brothers or four cousins”. But thousand twins giving their lives for just one? What could a gene look like that compels to sacrifice a village’s worth of individuals for one copy?

Iv.