Introduction Flashcards
Ecology definition
Scientific study of the interactions that determine the distribution and abundance of organisms
Individual
Biological entity with a unique genotype, capable of growth, maintenance and reproduction
-Unit of reproduction
-has a membrane/covering to transfer energy and materials with environment
Population
Group of individuals of the same species living in a certain area at a certain time
Unit of evolution
Community
Assemblage of individuals/ populations of different species living in a certain area at a certain time
Ecosystem
A biological community plus all the abiotic factors influenced by that community
Focus on the Flow of energy and matter in the system
Ecological system
Biological entity that has its own internal processes and interacts with its external surrounding
May be an individual, population, species, community, an ecosystem, landscape or biosphere
Why is biosphere a debated hierarchical organization of ecological systems
There is only one (earth), so hard to compare to other things
Ecological system input and output examples
Input: food, birth, immigration, colonization, solar energy, evolution of species
Output: death, waste, extinction, energy re-radiation, energy leaving system
Evolution
Descent with modification
-change in allele frequencies in a population
Mechanisms for evolution
-mutation
-natural selection
-genetic drift
-migration (gene flow)
Evolution holds part of the answer as to why species are _________
Where they are
Distribution and abundance
Phylogenies trees
Show evolutionary relationships
Even though from same phylum, some plants look different in which ways:
-how they get nutrients (autotrophic/heterotrophic)
-different environments (tree, soil, host)
-size
-shape
-colour
Producers
Create (transform inorganic to organic matter)
-autotrophic plants
Ex:
-chemosynthetic bacteria
-algae
-Cyanobacteria
-most plants
Mixotrophs
-receive nutrients from both photosynthesis and outside resources
Ex:
-algae
-protists
-some plants/ some animals
Consumers
Heterotrophs
Ex:
-Fungi
-Bacteria
-Herbivore
-carnivore
Hypothesis
Assumed explanation or answer to a question
-proximate: mechanisms (how?)
-ultimate: evolutionary perspective
Prediction
Statement regarding the future
Manipulative experiment
Manipulation or treatment in which replication, randomization and an experimental unit are used.
Selective abortion in E. havanense
Hypothesis and outcomes of tests
1. Not enough pollination: adding pollen manually did not increase fruit
2.not enough resources to mature fruits: Even when fruit removed manually, still same numbers aborted
3 moms are choosy based on donor: some pollen donors were preferred!!!!! Winner!
Hubbard Brook experiment
Studying the catchment area of watersheds. Started in 1963 and is ongoing. Results showed that do to deforestation, there is 13 times the normal rate of dissolved inorganic substances in the water shed.
Due to great reduction in evapotranspiration (because of lack of leaves) resulting in more precipitation going to ground water and causing more erosion. There are no trees to absorb and store these ions/ minerals
Some principles of ecology
- Principle of allocation (distributing)
- Populations do not grow infinitely
- Principle of competitive exclusion
- Liebig law if minimum
- Available energy decreases as trophic level increases
Adaptations
The characteristics of an organism that make it well suited to its environment
5 distinct properties of populations that are not exhibited by individuals
Geographic range (where it lives)
Abundance
Density (# per unit of area)
Change in size
Composition (sex, age)
Landscape
Includes multiple ecosystems that are connected by the movement of individuals, populations, matter, and energy
Interactions among ecosystems
Hierarchy of ecology
Biosphere
Landscape
Ecosystem
Community
Population
Individual
3 major biological principles
Conservation of matter and energy
-can’t be created or destroyed
-Can only change form
Dynamic steady states
-when gains and losses are in balance
Evolution
-change in genetic composition of a population over time
Types of consumers
-predators: kill and partially or fully eat individuals (+-)
-parasitoids: lay eggs on or inside other animals and larvae consume the host (+-)
-parasites: live in or on another organism (rarely kills) (+-)
-herbivory: consume producers (does not kill it, but eats small portion) (+-)
-competition: between two species that results negatively for both. (Live better far away) (- -)
-mutualism: when two species interact and each benefits (++)
-commensalism: two species live in close association and one receives a benefit, and other recipes neither. (+0)
Symbiotic relationship
A close physical relationship between two different types of organisms
Consumers of dead organic matter types
-scavengers: consume dead animals
-Detritivores: break down dead organic matter and waste products
-decomposes: break down dead organic material into simpler elements that can be recycled
Habitat
Place or physical setting in which an organism lives
Niche
The range of abiotic and biotic conditions an organism can tolerate
-temp
-humidity
-food
-predators
Manipulative experiments
A process by which a hypothesis is tested by altering a factor that is hypothesized to be an underlying cause of the phenomenon
Also known as treatment experiments
Experimental unit
The object to which we apply the manipulatioin
Randomization
Every experimental unit has an equal chance of being assigned a particular manipulation
Microcosms
Simplified ecological systems that attempt to replicate the essential features of an ecological systems
Natural experiment
Relies on natural variation in the environment to test a hypothesis
