Sensing and responding to the enviroment Flashcards
ideas about defining characteristics of life.
- Paul Davis: life meter, a device that use input data to estimate how close life is to evolution. How lifing thing process and store information
- Schrodiger : concept of entropy -> tendency of thing to become disorder due to random atom movement
- there are two aspect which keep them in-check:
- take in food (negative entropy), high level of order to combat disorder
- Build their body based on information form aperiodic crystal ( a stable place to store information) and pass on to the next generation. DNA
Biological maxwell demon
- help to maintain order
- channels and protein
Energy
-The ability to do work
Matter
anything that occupies space and has mass
information
-how data is store, express and pass on
Combating enthropy
-homeostasis ->pass on information
What is life
- exchange of energy, matter and information between individaul and their enviroment
- individuals are special – goal-directed
Scale in biology
- molecular (nanometer)
- molecular/cellular (micrometer)
- individual (micrometer to metre)
- population (mm to km)
- community (mm to km)
- ecosystem (mm to km)
Individual thermodynamic system
- thermodynamic is the study of heat exchange and how heat is converted
- the individual receive heat from its environment ( from the sun, air, etc)
- the individual receive energy from food
- the individual loses energy (heat) due to the environment or activity
- heat loss due to evaporation (water regulation)
Measuring metabolic rate
- direct ‘calorimetry’ = heat measurement
* indirect ‘calorimetry’ = gas measurement
• basal metabolic rate
is not moving is not digesting is in its thermoneutral zone (it isn’t feeling cold) is in its inactive phase is an adult is not reproducing
• standard metabolic rate
is not moving is not digesting is at a known temperature is in its inactive phase is an adult is not reproducing
• resting
is not moving
is not digesting
is in its thermoneutral zone (it isn’t feeling cold)
• mesuring field metabolic rate
doubly labelled water
-inject organism with “heavy water”, H2o with isotopes, measure the amount of heavy water remain after a set period of time
Animal body temperature
homeothermic(constant temperature)
endotherm( generates heat to raise body temperature above ambient)
heterothermic (variable temperature)
ectotherm (body temperature varies with ambient temperature)
Body size and metabolic rate
M = aW2/3. M= metabolic rate, W = weight
The metabolic web
• feeding • assimilation (digestion) • growth • maintenance • development (maturation) • reproduction either ontogeny (Grow and development) or life cycle (different stage of development) or life-history(organism grow affect population grow)
Growth Curves
- von-berg growth curve show gradually decrease in growth before reaching a stop M ≈ W2/3
- exponetial rise before a stop (insect) M ≈ W1
- The in between M ≈ W3/4
Temperature Tolerance
- different species have different range of temperature that they can be tolerate to.
- Endotherm have a narrower range compare to ecthoderm
Temperature Tolerance in cain toad
Survival: 5-40 ⁰C
Breed: water temp 25-30⁰C
Na+/K+ pump action is 0.8% optimum at 5⁰C
Behavioural Thermoregulation
- these are behavior that assisst animal in regulation of their body heat
- there is a wide range of beviour
Temperature response curves
- Each species have an upper and lower limit. Pass the limit mean death
- the metabolic rate would rise with the temperature (Q10) before slowing down after reaching the optimum temperature
- After the optimum tempereature, it would rapidly decrease
Topor
-A process which an organism lower their body temperature to lower their metabolism rate
different animal heat tolerant
- Generalist that have a wide range
- Specialist that is adapted to a smaller optimal range
An organism’s environment is changing constantly
Abiotic changes
• temperature, humidity, sunlight (and altitude, longitude, and substrate for mobile organisms)
Biotic changes
• temporal and spatial variation in the abundance of food, competitors, natural enemies (predators, parasites, pathogens) and reproductive partners
Cues for predators
Niko Tinbergen’s classic field experiment, in which the broken shell from a newly hatched
black-headed gull was placed at different distances from an intact egg, showed that the inside of the eggshell is conspicuous
Black-headed gull parents remove the broken egg shell immediately after their chick has hatched
A signal or cue must be recognizable
Selection must favour the evolution of the sensory mechanisms that allow the signal or cue to be detected
Six senses Sensory modalities (or channels)
- chemical
- electricity
- light
- magnetic
- mechanical
- sound