Lecture 1 - Ecology Flashcards
What is ecology?
The study of interactions between organisms and their environment.
Name the hierarchy of scales at which ecology can be studied.
Macromolecules - Cells - Tissues - Organs - Organism - Population - Community - Ecosystem - Biosphere.
Ecologists tend to skip to the organism level however not always as DNA can be studied in ecology.
Why is the hierarchy subjective?
The levels are hard to define.
What is a biological population?
A group of individuals of the same species in a given area that have the potential to interbreed and interact.
What is a community?
A unit of the natural World comprising of 2 or more different species, in a given area at a given time.
What is a statistical population?
Individuals within a specified time and space about which inferences are to be made.
What is an ecosystem?
The biological community together with it’s physical environment.
Why are populations not evenly distributed?
Due to factors such as:
- Immigration and emigration
- Resource availability
- Natural barriers eg. mountains
Endemic species
A species which only occurs in one place.
Example of a metapopulation.
Edith’s checkerspot butterfly
What problems occur with categorising communities?
- How do we know where a community begins and ends?
2. It’s a unit categorised by humans and therefore lacks relevance to the organisms within it.
What is the biological species concept?
“Species are groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups.” Mayr 1942
State the problems with the biological species concept?
- asexual reproduction
- fossils
physical barriers to organisms interbreeding
State the other species concepts.
- recognition: do they recognise each other?
- morphological: do they look the same, display the same behaviour?
What are the problems with the morphological species concept?
Organisms that look similar but are different species and organisms that look different but are members of the same species.
