Transcript Individuals (week 4)

Individuals
ESC 556 week 4
Indiviudal
• Basic unit
• Individuals vary in their conditions
• Asexual reproduction
Unitary vs. Modular
organisms
• Unitary organisms
• Determined form
• Form and sequence
• Modular organisms
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Units that can produce similar units
Sessile
Plants – leaves & flowers
Genet
Much greater variation
Time sequences apply to each module
Death results from external factors
Ecological
Physiology
• Internal adjustments to external changes
• Resist/tolerate
• Regulation & Adaptation
• Migration
• A lot of different environments
• Homeostasis – sea to freshwater & land
• Conformation & regulation
• Eury vs. steno
• Poikilo vs. homoio
• Ectotherms vs. endotherms
Resistance and
Tolerance
• Stress response
• Response curve
• Individual differences
• Tolerance vs. resistance
• Deserts, arctic/antarctic, wavy shores
DESERTS
• Low densities of life and biodiversity
• Dry / daily temperature fluctuations
• Conserve water and control temperature
• Xerophytes
• Seeds at dry periods
• Allelopathy
• Animals – small & active at night
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Snakes & Lizards
Metabolic water
Insulation
Tolerant of dehydration and body temperature fluctuations
adaptation
• Evolutionary changes over time
• Survive competition & complex environmental variables
• Long vs. short term adaptation (acclimatization)
METABOLIC rate
• Amount of energy used per unit time
• Growth, reproduction, body maintenance, locomotion
• Metabolic rates vary
• Basal metabolic rate vs. daily energy expenditure
• Life style and body size
• Ectotherms – poikilothermic
• Endotherms – homoiothermic
• 25-30 X
METABOLIC rate
• Body size
• Large organisms
• Relative to their body mass
METABOLIC rate
• Ectotherm strategy – Low energy system
• Low resting metabolic rate, torpor, serpentine shapes
• Very abundant and diverse
• Endotherms – High energy system
• Independent of environmental conditions
• Foraging at night, inhabiting high latitudes
• Lower production efficiency
• Assimilation efficiency
• 20-90%
• Respiration, growth & reproduction
• Growth & reproduction efficiency
Locomotion
• Inertia & drag
• Reynolds number
• Aquatic organisms
• Locomotory activity
• Reduction in sinking rates – spines/body extensions
behaviour
• Survive and reproduce
• obtain food, avoid predation, find mates & resources
• Respond by growth (plants) or locomotion (animals)
• Energetic consequences and requirements
Sedentary or mobile
• Sessile organisms
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Low energy but risky
Protective mechanisms
Tolerating environmental conditions or stable habitat selection
Food capture indirect
Sexual reproduction difficult
Dispersal at any life stage
• Mobile organisms
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Escape mechanisms
Taxic behaviour & dispersal
Food search
Sexual reproduction easier
Dispersal at any life stage
Behavioral mechanisms
• Response to biotic and abiotic stimuli
• Growth – sexual reproduction
• Costs and benefits
• Plants
• No nervous system – chemical coordination
• Tropisms
• Phototropism, geotropisms
• Nasties
• Non-directional movements of part of a plant
dIspersal and
migration
• Passive vs. active dispersal
• Individual activities  population level consequences
• Seasonal, diurnal or tidal cycles effects
• Migration: movement of groups of individuals
• Key points
• Minimize intraspecific competition
• Colonize new niches
• Response to variation in conditions and resources
Avoidance and
dispersal
• Avoid competition between future generations and parents
• Adverse conditions, resource limitations, competition
• Spatial avoidance
• Temporal avoidance
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Diapause
Hibernation
Aestivation
Migration
Behavioral mechanisms
• Animals
• Nervous system
• Chemical responses
• Innate behaviours
• Genetically-based – taxes, kineses & instinctive behaviour
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Learned behaviour – habituation & conditioning
Imprinting
Feeding behaviour
Social behaviour – e.g. altruism
Reproduction
• Genetic material transfer from parental generation to progeny
• Asexual
• Single parent
• Mitosis - Clones
• Mutation
• Types
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Fission
Sporulation
Budding
Fragmentation
Vegetative propagation
mitosis
reproduction
• Sexual Reproduction
• Two parents
• Fusion of haploid gametes
• Energetically costly
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Broadcast fertilization
• Meiosis
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Recombination
• Advantages
• Variation
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Sperm & ova vs. + & Dioecious
Hermaphrodites
Parthenogenesis
Life Cycles and Life
history strategy
• Zygote of one generation to the next
• Alternation of generations
• Sporophyte and gametophyte generations
Life Cycles and Life
history strategy
• Cyclic polymorphism
Life Cycles and Life
history strategy
• Parasite life cycles
Life Cycles and Life
history strategy
• Life history
• Growth, differentiation, reproduction
• Abiotic and biotic interactions
• Evolutionary processes
• Plasticity
• Size
• Growth & Development Rates
• Reproduction
• Storage mechanisms
• Dormancy
Size
• Species, individuals, life stages
• Advantages of increased size
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Higher competitive ability  reproductive success
Increase success as a predator
Decrease predation risk
Reduced surface:volume ratio
• Better homeostatic control
• Bergmans’s rule
• Disadvantages of increased size
• Preferred food items
• Greater energy requirement
Growth and
Development Rates
• Development: differentiation of morphological and
physiological processes
• Development vs. growth
• Different rates and strategies of development
• Early
• Arrested
Reproduction
• Diverse strategies
reproduction
• Iteroparous vs. semelparous reproduction
• Method of fertilization & parental care
• Broadcast fertilization
• Copulation
Storage Mechanisms
• Irregular supply of resources
• Accumulation during abundance
• Fats, starch, glucose
• Food stores
Dormancy
• Periods of adversity
• Minimal metabolic activity
• Facultative vs. obligate
• Forms
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Resting spores or buds
Diapause
Hibernation
Aestivation
• Resistant external coat
• Synchorinization
• Predictive vs. consequential strategies
Feeding strategies
and mechanisms
Autotrophic
Heterotrophic
Photosynthetic
All green plants + green &
purple sulphur bacteria
Few: e.g. purple nonsulphur bacteria
Chemosynthetic
Nitrogen cycle bacteria
Most bacteria, parastiic
plants, all fungi + animals
Feeding strategies
and mechanisms
• Photoautotrophs
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Light
Nutrients
Water
Carbon Dioxide
• Terrestrial plants
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Water & Nutrients
• Aquatic plankton
• Light & Nutrients
• Insectivorous plants & nitrogen fixing nodules (legumes)
• Photoheterotrophs
Feeding strategies
and mechanisms
• Heterotrophs
• Holozoic
• Symbiotic
• Parasitic
• Feeder types
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Microphagous
Macrophagous
Fluid feeders
Saprophytes
Holozoic nutrition
Symbiotic nutrition
• Mutualism
• Corals
• Ruminant mammals
• Commensalism
ParasitiC Nutrition
• Ectoparasites & Endoparasites
• Obligate vs. facultative
Microphagous
Feeders
• Pseudopodia & food vacuoles
• Cilia
• Filter feeders
• Setose/ciliary mechanisms
Macrophagous
Feeders
• Scraping & boring
• Tentacular
• Whole ingestion
• Biting and chewing
• Detritus
Fluid feeders
• Sucking – proboscis
• Piercing & sucking