How did single celled organisms evolve into multicellular organisms?

Question

I feel like this part of evolution is kind of skipped over by historians. The more I think about it the more it hurts my brain

In: Biology

Answer 1

There’s a theory where symbiosis also helped in the formation of multicellular organisms. Single-celled beings who teamed up with other single-celled beings to cover up each other’s vulnerabilities so they could thrive in an unforgiving environment together rather than perish separately. Because of this you had symbiotes living together who flourished together, intermixing and sharing lifespans and genetic make-up till they became completely dependent on each other unable to exist alone, forming the first multicellular organisms.