Levels of biological organization

1
Levels of biological organization

• Molecules
• Cells
• Tissues
• Organs
• Systems
• Individuals
• Populations
• Communities
• Ecosystems

the scope of ecology
2
Organisms interact with the environment

• Features of the environment affect species
  distribution and abundance.
•  
• - requirements for survival and reproduction
• - challenges to survival and reproduction

3
Organisms interact with the environment

• Environment Biotic Abiotic

• physical requirements
• physical challenges

What are some things that organisms need or
that may present challenges?
4
Organisms interact with the environment

• Important abiotic factors
• - temperature
• - light
• - water
• - salinity
• - pH
• - wind/turbulence
• - nutrients

5
What determines climate?

• Angle of the earth
• Global temperature differences
• influence rainfall, ocean currents, wind

- intensity of sunlight - day length
6
Variation in temperature, light, moisturea
matter of scale

• Macroclimate global and regional patterns
  depends on latitude, altitude, habitat type
• Microclimate local scale
• vegetation, rocks, burrows, slope
• create shade and protect from wind

7
Every species has an optimal temperature

• different species have different optima 

8
Optimal temperature for lizard sprinting
morph a
morph b
sprint speed (m / sec)
(Huey, R. B. and J. G. Kingsolver, 1993)
lizard body temperature (oC)
1. What is the trait that differs between
morphs? a. body temperature b. sprint speed
c. temperature at which maximum speed
is attained 2. In what kind of environment
would natural selection favor individuals
of morph a over those of morph b?
9
Thermal optima are adapted to temperature
Im outta here!!
temperature at which izard runs fastest (oC)
mean temperature in lizards habitat (oC)
10
Problems at low temperatures

• slower rate of cellular processes ?
• ? lower physiological activity for ectotherms
• body temp tracks temperature of environment
• endotherms expend energy to stay warm
• use metabolic heat to regulate body temp
• cells cant usually tolerate freezing

11
Ectotherms grow slowly at cold temperatures
Green frog tadpoles
(Berven et al. 1979)
tadpole size
lowland
montane
temperature
What limits the distribution of this frog?
12
Problems at high temperatures

• protein stability

moderate temperature
loss of water to stay cool evaporative
cooling
13
Coping with extreme temperatures

• behavior
• choice of microclimate
• - migration

14
Coping with extreme temperatures

• escape in time
• dormancy
• spores, seeds, cysts can often
• survive freezing or fire
• hibernation, torpor
• endotherms reduce metabolism
• to conserve energy

15
Coping with extreme temperatures

• structures
• fur, feathers, fat
• coloration
• reflect or absorb light
• surface area volume

Everything Alaska
Phillip Greenspun
Lake Superior Zoo
16
Coping with extreme temperatures

• acclimation
• physiological adjustment leads to tolerance

17
Abiotic factors that can affect organisms

• temperature
• light
• moisture
• wind
• nutrients
• salinity
• pH

18
Conserving water

• physiological adaptations
• nasal passages and kidneys
• of kangaroo rats
• CAM plants close stomata
• during the daytime

19
Conserving water

• protective coverings
• waxy coatings on leaves
• waterproof skin
• eggshells

20
Salinity is an osmotic challenge

• osmoregulation regulation of salts versus water

drink seawater and excrete salt
21
Salinity is an osmotic challenge

• osmoregulation regulation of salts versus water

excrete water
22
Salinity is an osmotic challenge

• osmoregulation regulation of salts versus water

many marine invertebrates are isosmotic
H2O
NaCl-
23
What is the niche?

• set of conditions
• within which an organism
• can maintain a viable
• population
• multi-dimensional
• with as many
• dimensions as their
• are limiting conditions

ecological niche
light intensity
okay
temperature
salinity
24
Energy flow through ecosystems
sunlight
CO2
plants
energy
detritivores
herbivores
carbon
carnivores
energy carbon
25
Energy flow through ecosystems
sunlight
CO2
adaptations to acquiring CO2
adaptations to being eaten
plants
adaptations to eating plants
detritivores
herbivores
adaptations to being eaten
carnivores
adaptations to eating animals