The importance of private property in biology

Photos by Joan unless

otherwise specifiedStrassmann/ Queller lab group

The importance of property and privatization in social evolution

Joan E. Strassmann & David C. [email protected]

Read my blog on how to become a professor!http://sociobiology.wordpress.com

John Templeton Foundation

What unites us?

What unites us?Insects: social wasps, social bees, ants, & termites

What unites us?Insects: social wasps, social bees, ants, & termites

Topic: altruism, sociality, and their evolutionary, behavioral, physiological, and ecological consequences

Why is what we do so important?

Theories derived from studies of social insect altruism and its consequences are powerful for understanding life.

Privatization and property

Privatization is a neglected topic in biology

Strassmann and Queller, Animal Behaviour, 2014

Private property includes all resources kept from others, excluding one’s own

body, or those of one’s progeny.

What is privatizing behavior?• Actions that restrict a resource from others,

taking it for oneself.

Territoriality is perhaps the best known kind of privatization

Sometimes defense covers a single resource

Broad-tailed hummingbird defends feeder

An individual may attempt to privatize a group of mates

Female elk and young

Another way to privatize a resource is to hide it

Pygmy nuthatch collects and caches seeds

You can defend a resource by internalizing itGiant clams contain algae

Tridacna giant clam from Komodo National Park, Nick Hobgood, Wikimedia Commons CC 3.0

Giant clam Tridacna gigas, alga Symbiodinium croadriaticum, from Douglas

A fortress may privatize a resource, making it easier to defend

How to privatize resources:

Great egret nests at High Island, Texas

• Territoriality• Defense• Concealment• Fortress• Internalization

What are the benefits of privatizing?

• Restricted access to resources

• Increases future resource predictability

• Resource enhancement benefits self, or family

What are the costs to

privatizing?

• Privatizing takes energy

• Might involve conflict

• Takes away from other activities

Special relationship of

privatization with sociality

• Benefits can go to relatives

– Includes next generations, so enhancement can pay off even when slow

Special relationship of

privatization with sociality

• Easier to privatize with division of labor

– Even a group of just two can have a forager and a guard

– Larger groups can have specialists of many kinds

Special relationship of

privatization with sociality

• Resource can be used prudently

– Can save some of the resource for time of scarcity

– Avoid tragedy of the commons

– Allow living resource to grow

Special relationship of privatization with sociality

• Allows longer term relationships and resource enhancement

• Can lead to spectacular structures http://upload.wikimedia.org/wikipedia/common

s/4/42/Cathedral_Termite_Mound_-_brewbooks.jpg

Special relationship of privatization with

sociality

• Benefits can go to relatives

• Easier to privatize with division of labor

• Resource can be used prudently

• Allows longer term relationships and resource enhancement

How might social insect studies benefit from attention to privatization?

Perhaps most interesting are those cases where privatization is lost.

Scott Bauer, http://www.ars.usda.gov/is/graphics/photos/

The combination of

privatization and sociality is very important

in microbesCDC Public Domain

Staphylococcus aureus on catheter

Bacteriocins are produced by bacteria that die to help relatives

Dying bacteriocin producing bacteria are black.Their zone of bacteriocin influence is red.

Bacteriocins do not kill bacteria of their own type

Close relatives immune to bacteriocin are open black shapes, indicating they are alive

Bacteriocins do kill less related bacteria

Non-relative bacteria are green, die (solid shape) when hit by bacteriocin, live (empty green) when away from bacteriocin

Dictyostelium discoideum, a social amoeba

Social cycle develops under starvation when some cells die to become stalk

Kessin 2000

Some clones carry bacteria through the social stage

Micrographs of sorus contents

Spores

Spores

Bacteria 5µm

12 genetically-distinct clones collected from a small transect in Va.Experienced same environment; access to same potential food

Study population:

Non-farmer

Farmer

0

10

20

30

40

Soil 1 Soil 2

Fold

incr

eas

e

in s

po

res

Farmer

Farmer clones have their own lunch kit when the spores hatch in a new place.

1.3-2.2 x 108

CFU’s/gm soil

0.6-0.64 x 108

CFU’s/gm soil

What keeps farmers from losing their carried bacteria to non-farmer clones?

Besides the food bacteria, the farmers also carry bacteria they use as weapons

D.discoideum farmer clones

Location collected Closest relative in GenBank % Identity

5 clones Mt. Lake, VA Burkholderia xenovorans LB400 98

2 clones Mt. Lake, VA Stenotrophomonas maltophilia K279a 98

2 clones Mt. Lake, VA Enterobacter sakazakii ATCC BAA-894 98

3 clones Mt. Lake, VA Pseudomonas fluorescens Pf-5 98

2 clones Mt. Lake, VA Burkholderia phytofirmans psJN 97

4 clones Lake Itaska, MN Flavobacterium johnsoniae UW101 93

Supernatants from B. xenovorans cultures harm non-farmers and benefit host farmers

36

% c

han

ge in

sp

ore

pro

du

ctio

n

FarmerNon-farmer

We have identified the small molecules responsible for privatizing in another weapon, Pseudomonas fluorescens

We have identified the small molecules responsible for this effect in another weapon, Pseudomonas fluorescens

Chromene diminishes non-farmer growth, augments farmer growth

Stallforth et al. PNAS 2013

Pyrrolnitrin diminishes non-farmer growth, augments farmer growth

Privatizing is probably the commonest and most effective solution to the

tragedy of the commons

Isn’t it ironic that selfish gene, sociobiology turned first to cooperative

solutions to social problems?

© 2005 Tree of Life Web Project

A little taxonomic adventurousness is fun!

John Templeton Foundation