Help, I need somebody!

I play this game with my kids. It's a 'guess-who' game: Think of an animal, person, object and then try to describe it to another person without giving away the real identity. The other person has to guess what/who you are. You have to get in character and tell a story: What do you do, how do you feel, what do you think and want?

Let's have a go. Read the character scenarios below and see if you can guess who/what they are.

"It's just not fair! Mum says I'm getting in the way, I'm a lay-about and she can't afford for me to stay with her any more. But I like being in a big family, and I don't want to leave. Mum says that if I am to stay home, we'd need some kind of 'glue' to keep us from drifting apart. Glue is costly and she says she hasn't the energy to make it since she's busy making babies. But then I had this brilliant idea: how aboutImake the glue using a bit of cell wall (mum won't mind), add some glycoproteins (they're a bit sticky, so I have to promise mum I'll wash my hands afterwards) and bingo! Job done: we've got ourselves a nice cosy extracellular matrix! I'm happy doing the bulk of the work, so long as mum keeps giving me more siblings. I suggested this to mum last night, and guess what? She said yes! But she also said I'm out the door if I don't keep up my side of the bargain: no free-riders…."

Who am I?

"I am a uni-cell becoming multicellular. If I group with my relatives then someone needs to pay the cost of keeping us together—the extracellular matrix. I don't mind paying that cost if I benefit from the replication of my own genes through my relatives."

Ok, that was a tough one. Try this one:

"I'm probably what you'd call the 'maternal type'. I like having babies, and I seem to be pretty good at it. I love them all equally, obviously. Damn hard work though, especially since their father didn't stick around. I can't see my latest babies surviving unless I get some help around the place. So I said to my oldest the other day, fancy helping your old Ma out? Here's the deal: you go find some food whilst I squeeze out a few more siblings for you. Remember, kid, I'm doing this for you—all these siblings will pay off in the long run. One day, some of them will be Mas just like me, and you'll be reaping in the benefits from them long after you and I are gone. This way you don't ever have to worry about sex, men or any of that sperm stuff. Your old Ma's got everything you need, right here. All you have to do is feed us, and clear out the mess!"

Who am I?

"I am an insect becoming a society. If I nest alone I have to find food which means leaving my young unprotected. If some of my grown-up children stay home and help me, they can go out foraging whilst I stay home to protect the young. I can have even more babies this way, which my children love as this means more and more of their genes are passed on through their siblings. Anyway, it's a pretty tough world out there right now for youngsters; it's much less risky to stay at home."

"I could also be a gene becoming a genome, or a prokaryote becoming an eukaryote. I am part of the same, fundamental event in evolution's playground. I am the evolution of helping and cooperation. I am the major transition that shapes all levels of biological complexity. The reason I happen is because I help others like me, and we settle on a division of labour. I don't help because, paradoxically, I benefit. My secret? I'm selective: I like to help relatives because they end up also helping me, by passing on our shared genes. I've embraced the transition from autonomy to cooperation. And it feels good!"

The evolution of cooperation and helping behaviour is a beautiful and simple explanation of how nature got complex, diverse and wonderful. It's not restricted to the charismatic Meerkats, or fluffy bumble-bees. It is a general phenomenon which generates the biological hierarchies that characterise the natural world. Groups of individuals (genes, prokaryotes, single-celled and multicellular organisms) that could previously replicate independently, form a new, collective individual that can only replicate as a whole.

Hamilton's 1964 inclusive fitness theory is an elegant and simple explanation why sociality evolves. It was more recently formalised conceptually as unified framework to explain the evolution of major transitions to biological complexity in general (e.g. Bourke's 2011 Principles of Social Evolution). Entities cooperate because it increases their fitness—their chance of passing on genes to the next generation. Beneficiaries get enhanced personal reproduction; helpers benefit from the propagation of the genes they share with the relatives they help. But the conditions need to be right: the benefits must outweigh the costs and this sum is affected by the options available to independent replicating entities before they commit to their higher-level collective. Ecology and environment play a role, as well as kinship. The resulting division of labour is the fundamental basis to societal living, uniting genes into genomes, mitochondria with prokaryotes to produce eukaryotes, unicellular organisms into multicellular ones, and solitary animals into eusocieties. This satisfyingly simple explanation makes the complexities of the world less mysterious, but no less wonderful.

If only adults indulged a bit more in children's games, perhaps we'd stumble across simple explanations for the complexities of life more often.