Saturday, 22 September 2007

Predation, Parasitism, Commensalism, and Mutualism in the Garden and in the Community

Every fall death stalks my garden in the form of this beautiful but deadly predator, the Great Blue Heron. No frog or fish is safe and often one or two of the careless will disappear before I can dispatch Ruby to chase it away.

Predators come in many shapes and sizes, like this cute little toad:

Ruby had heard that toad licking was all the latest rage, but she tells me that no, licking a toad doesn't actually give you a good buzz.

The praying mantis is one of my favorite insect predators.

Predators serve a role, but they result in the death of the prey. Predators in the community are something we'd all like to live without, but predation is a fact of business life just as it is in our environment.

My garden is also full of parasites and of all these, the leech is the most disliked.

Parasites don't actually kill their victim, but they do cause harm. Apparently leeches have medicinal use because of the anti-clotting agents in their saliva but I'd still don't like them. Often a community will have a few parasites as well. There are always a few people who are just like leeches, i.e., they drain away your lifeblood until sated giving nothing in return but a scar.

But, in a community, commensalism is the norm. The users of open source software benefit and in doing so cause no harm. Just as this frog uses a lily as a convenient platform from which to ambush its prey without harming the flower.

What we'd like to achieve in a community is mutualism where both parties in the interaction benefit. This bee on a sunflower is a prime example, benefitting from the nectar and the pollen while ensuring the diversity of the sunflower gene pool by transporting the pollen from flower to flower:

A thriving community is driven by mutually beneficial behaviors. Users help test the software and help make it better with suggestions. Some individuals eventually become contributors and will directly enhance the software. Others might help document it thereby making it more consumable for others. A few will even strive to become committers to invest even more of themselves.

For quite a few weeks now I've been watching the geese practice flying in formation. They tend to do this every evening for the late weeks of summer.

I find this a particularly striking example of mutually beneficial behavior at work. Most folks probably know why geese fly in formation and it's not because they just love to hang out together. The goose flying the front has to do the most work, and those behind benefit by virtue of getting a little bit of extra lift from the turbulence created by the goose in front. They need quite a bit of practice to learn how to fly in this way. Each goose will take turns leading, and when it tires, it will peel away, falling back to the rear, allowing the next goose in line to take the lead. In this way, all the geese benefit and get to their destination with less effort than it would take to get there alone.

Let's try to be like the geese and act cohesively for the mutual benefit of our whole community.


Scott Lewis said...

Enjoyed your beautiful pictures and metaphor Ed.
It would be interesting and entertaining to query people's opinions about who in the Eclipse community are the predators, the parasites, and the 'mutualists'. But too scary for some to actually be done, I guess.

AlBlue said...

Yeah, I'm interested in who the leeches are, too.

lucas said...

some lines from the JFK Speech at Rice University, Houston, Texas
September 12, 1962.

I'm not that clever at metaphoring, this is what comes to my mind sometimes when thinking about Eclipse & meta modeling challenges.

It is probably a bit far from all mutualism & commensalism stories, but as for me, it can fairly illustrates some of fears/hopes surrounding the Eclipse community at the moment.


"We set sail on this new sea because there is new knowledge to be gained, and new rights to be won, and they must be won and used for the progress of all people. For space science, like nuclear science and all technology, has no conscience of its own. Whether it will become a force for good or ill depends on man, and only if the United States occupies a position of pre-eminence can we help decide whether this new ocean will be a sea of peace or a new terrifying theater of war. I do not say the we should or will go unprotected against the hostile misuse of space any more than we go unprotected against the hostile use of land or sea, but I do say that space can be explored and mastered without feeding the fires of war, without repeating the mistakes that man has made in extending his writ around this globe of ours.

There is no strife, no prejudice, no national conflict in outer space as yet. Its hazards are hostile to us all. Its conquest deserves the best of all mankind, and its opportunity for peaceful cooperation many never come again. But why, some say, the moon? Why choose this as our goal? And they may well ask why climb the highest mountain? Why, 35 years ago, fly the Atlantic? Why does Rice play Texas?

We choose to go to the moon. We choose to go to the moon in this decade and do the other things, not only because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too."


lucas said...