Societies and shelter - part 2

Question 1

Why do societies use a shelter?

Answer 1

A shelter establishes a “factory within a fortress”

Question 2

explain a “factory within a fortress”

Answer 2

a protected, defensible location where offspring production can be maximized.

Question 3

when is shelter usage in all organisms selected for?

Answer 3

when enhanced protection from biotic and abiotic interactions boosts reproduction to a level that outweighs the costs of finding/constructing a shelter and maintaining it.

Question 4

Key ecological interactions altered by shelter usage

Answer 4

1. Environmental buffering and tolerance.
2. More invincible “invincible center” for increasing or stabilizing space use.
3. Augmented food acquisition and processing

Question 5

environmental buffering and tolerance - what can a shelter buffer against

Answer 5

Desiccation, drowning, temperature extremes and variation

Question 6

environmental buffering and tolerance - what do buffering benefits of nests allow

Answer 6

tolerance of ecological space that would otherwise not be be tolerable.

Question 7

Examples of temperature buffering and tolerance

Answer 7

• Optimal daily maximums in temperature.
• Daily fluctuations in temperature.
• Seasonal fluctuations in temperature.
• Latitudinal gradient in temperature.

Question 8

temperature buffering and tolerance - optimal daily maximums in temperature examples

Answer 8

• rock ants
• turtle ants

Question 9

optimal daily maximums in temperature - rock ants

Answer 9

• Shelter under a rock to increase temperature for offspring rearing
• brings maximum up

Question 10

optimal daily maximums in temperature - turtle ants

Answer 10

• shelter inside dense wood to be insulated against high and low desert temperature
• brings maximum down

Question 11

temperature buffering and tolerance - daily fluctuations in temperature example

Answer 11

ant nest structure

Question 12

daily fluctuations in temperature - ant nest structure

Answer 12

Allows adjustment to optimal temperature for offspring rearing by moving offspring up (warmer temp) and down (cooler temp) in the nest structure throughout the day

Question 13

temperature buffering and tolerance - seasonal fluctuations in temperature example

Answer 13

• deep nest architecture
• The “winter ant”

Question 14

seasonal fluctuations in temperature - deep nest architecture

Answer 14

deep nest architecture allows tolerance of winter cold in warmer, deeper soil and allows cold-weather activity.

Question 15

seasonal fluctuations in temperature - the “winter ant”

Answer 15

• because of winter cold tolerance in their deep nest, they are active when other ants are sealed in their nests
• avoid competition with other ants and
  thermal pressures in the summer

Question 16

temperature buffering and tolerance - latitudinal gradient in temperature example

Answer 16

“frost line” impact on ants

Question 17

latitudinal gradient in temperature - “frost line” impact on ants

Answer 17

Only ants that are ground nesting or nest deep in tree trunks have nests that allow them to tolerate colder temperatures.

Question 18

More invincible “invincible center” - all shelter-dwelling societies do what?

Answer 18

• defend against intruders in the shelter
• a shelter therefore buffers against full displacement from occupied ecological space

Question 19

more invincible “invincible center” - what can a shelter increase?

Answer 19

• space use and territorial dominance
• especially if a species uses multiple nests

Question 20

more invincible “invincible center” - Multiple nests and space usage example

Answer 20

weaver ants

Question 21

multiple nests and space usage - weaver ants

Answer 21

Weaver ants build smaller nests at territory boundaries, filled with bigger ants

Question 22

Augmented food acquisition and processing - without a shelter

Answer 22

food processing and acquisition is exposed to a range of biotic and abiotic pressures and fluctuations.

Question 23

augmented food acquisition and processing - with a shelter

Answer 23

acquired food items can be better harvested, stored and processed.

Question 24

augmented food acquisition and processing - benefits to a shelter

Answer 24

• provide access to new types of food
• new feeding niche

Question 25

augmented food acquisition and processing - examples of new feeding niche

Answer 25

- Larger prey items. - Stored plant materials (e.g. seeds) - Farming.

Question 26

augmented food acquisition and processing - example of farming

Answer 26

ants “livestock” farming

Question 27

augmented food acquisition and processing - ant's "livestock" farming

Answer 27

- some ants farm root-sucking, sugar-producing insects in underground nests (form of mutualism) - ants (new world) and termites (old world) conduct fungus gardening

Question 28

what is an "extended phenotype"

Answer 28

The idea that the phenotypic expression of an organisms genotype is not limited to its body and internal processes alone.

Question 29

example of an "extended phenotype"

Answer 29

- constructed shelters: beaver lodge, ant nests

Question 30

how may a phenotype be "extended"

Answer 30

- it can be “extended” to include external products of the genotype - mostly via genome encoded behaviors, that impact the organism’s fitness.

Question 31

How do we know if a shelter is an extended phenotype?

Answer 31

If a built shelter is an extended phenotype, variation in shelter structure should impact fitness.

Question 32

within a lineage of social species, what should evolve and what should it attain?

Answer 32

- differences in shelter structure should evolve - and it should attain complex functional architecture that benefits each species in the specific ecological contexts they inhabit

Question 33

define niche construction

Answer 33

the process in which an organism alters its own environment to change its occupied niche space in a way that increases its fitness

Question 34

how can niche construction be seen

Answer 34

- it can be seen as individual space use that cascades up to larger scales of space use - the organism is creating and defining its own fundamental niche.

Question 35

what can make nice construction more extensive?

Answer 35

if the society alters the surrounding environmental conditions they face by building a shelter

Question 36

niche construction example

Answer 36

leaf-cutting ants

Question 37

nice construction: leaf-cutting ants - environmental conditions they modify

Answer 37

- Temperature - Airflow - Moisture - Hygiene

Question 38

define ecosystem engineer

Answer 38

An organism that causes state changes in the environment that subsequently serve as vital resources for other organisms

Question 39

what can ecosystem engineers be responsible for?

Answer 39

dictating the realized and fundamental niches of other organisms

Question 40

What category of biotic interaction is most ecosystem engineering?

Answer 40

- commensalism (most common) - mutualism (rare)

Question 41

ecosystem engineer - extreme case

Answer 41

the biogeographical distribution of other species is also dictated by the ecosystem engineer’s own biogeographical distribution.