Adios, amoebas!

October 19, 2007 7:10 AM

Social amoebas Dictyostelium discoideum respond to a dwindling food supply by clustering into a multicell colony and moving to a place suitable for making spores.

In the process, some amoebas take on specialized roles. Some of those roles involve sacrificing themselves for the survival of the colony. Individual amoebas that shirk those roles have a lower reproductive rate, and their genes disappear.

posted by Kirth Gerson (11 comments total)

And the anti-social amoebas stand around making fun of the social amoebas.

But seriously, this is a very interesting article. Thanks, Kirth Gerson.
posted by amyms at 7:27 AM on October 19, 2007

Fascinating stuff! A few years ago I wrote a profile for Wired of Bonnie Bassler, the woman who discovered the molecular language behind the social behavior among bacteria, which is known as "quorum sensing." Learning that a thin layer of dental plaque is an elaborate construction of various organisms who parse out different tasks to one another in a bacterial division of labor -- you bond to the teeth, you assist in fluid transport, you create a hard shell so we can't be brushed away -- blew my mind.

The world is cooperative from the bottom up.
posted by digaman at 7:36 AM on October 19, 2007 [1 favorite]

> The world is cooperative from the bottom up.

Up? Up to what level? Let's see the human race get together and extrude a fruiting body. Or, indeed, anything.
posted by jfuller at 8:09 AM on October 19, 2007

You're soaking in it, jfuller.
posted by digaman at 8:27 AM on October 19, 2007

The meek socially conscious shall inherit the earth.

digaman: I heard Bassler on NPR some time ago talking about bacteria communication and it blew my mind. It was one of those moments where I was driving in the car, got to my destination, and sat parked in the lot for another twenty minutes to hear the rest of the piece. I'm going to read your article later today.
posted by Terminal Verbosity at 8:27 AM on October 19, 2007

awesome.
posted by digaman at 9:38 AM on October 19, 2007

From the FPP's Damn Interesting article:

The slug begins to seek out light, leaving a slimy trail behind. Some of the amoebas take on the difficult role of sentinel, or immune-like functions. They circulate through the slug, hunting for pathogens. If they find any, they will engulf them in a process similar to the feeding behavior they once displayed when in solitary form. The pseudoplasmodium periodically sloughs off the sentinels– and any pathogens they have engulfed– and abandons them in the trail of slime. More cells will then be tapped to fill their place.

So what are we up to now, over 60,000 members? Maybe it's time to move out!

More Dictyostelium slime mold video sequences at the Zoologisches Institut München.
posted by cenoxo at 9:47 AM on October 19, 2007

as an aside, this behavior is also alluded to in the October issue of The Atlantic Monthly which examines the evolutionary basis for altruism and selfless behavior. It's a nice article to read through when one feels convinced that human nature has devolved down to brutality and xenophobia barely restrained by a thin veneer of civility and self-interest.
posted by bl1nk at 10:15 AM on October 19, 2007

It was only a matter of time.

We must invade Amoeba World before they begin nuclear testing.
posted by tkchrist at 12:19 PM on October 19, 2007

See Dictyostelium and much more in the delightful film Death By Design.
posted by eccnineten at 3:48 PM on October 19, 2007 [1 favorite]

I have fairly convinced myself that human consciousness extends well outside our brain, and incorporates not only our nervous system, but our other communications systems as well: hormonal, intra-cellular, etc.

This sort of article only further convinces me. If a pack of amoeba can achieve a state of environmental consciousnes that causes them to team up and move around, then perhaps my gut bacteria communicate their health and status to my brain, which uses the information when selecting foods. It might explain why I sometimes have cravings for a specific type of food.
posted by five fresh fish at 6:20 PM on October 19, 2007