Lecture 5 + 6 - Predation Flashcards
What is competition theory? [1]
Exponential growth - Intraspecific competition - Interspecific competition.
What is an equation for a line in competition theory? [1]
N1 = K1 - α12N2
K1 - Intercept [intraspecific]
α12 - Gradient
[interspecific K adjustment]
What happens ‘on the line’ of a population growth size graph between two species? [1]
On the line, means there is zero population growth.
As everything goes ‘towards the line’.
What’s the difference of a competitive exclusion graph? [1]
The species isoclines don’t cross, so the species with the largest K should eventually outocmpete the other.
What is intraspecific equilibrium? [1]
When individuals coexist where Births = Deaths
What happens in coexistence in terms of isoclines? [1]
The isoclines cross and get pushed towards the same point.
What happens in an unstable equilbrium in terms of isoclines? [1]
They get pushed towards different K’s, so eventually one species will outcompete the other.
Give six examples of competition. [6]
Exploitation [resource depleetion]
Pre-emptive [using space]
Overgrowth [light deprivation]
Chemical [toxins]
Territorial [fighting]
Encounter [transient]
What did Tansley 1917 investigate? [2]
Growth rates of G saxatile and G sylvestre under calcareous and acid soil types.
What did Tansley 1917 conclude? [2]
Coexistence causing a reduction in abundance, but intraspecific competition must be stronger than interspecific.
What did Park 1954/62 investigate? [1]
Competitive exclusion between two beetles, T. Confirsum and T cataneum.
What did Park 1954/62 conclude? [2]
Complete competitive exclusion can happen in warm moist (benefitting T. cataneum) or cool dry (benefitting T. confirsum).
However, coexistance may occur in some temperatures.
What did Connell 1961 investigate and conclude? [1]
That Chtamalus and Balanus barnacles can coexist but still compete against each other.
What is allopatric speciation? [1]
Geographical separation causing speciation.
What is sympatric speciation? [1]
Speciation occuring within the same geographical area.
What did Crombie 1941 study? [1]
What did he conclude? [1]
Rhizopertha and Sitoraga
He concluded coexistance.
How may a caterpillar prevent plant resource defence? [1]
They can eat around the leaf in a circle, spitting stuff to prevent plant defence.
Why zebra stripey? [1]
Because suggested disease defence.
What’s batesian mimicry?
Normo mimics a harmful model
What’s Mullerian mimicry?
Two unpalatable mimics mimic each other
What is the contingency model of foraging? [2]
Choose most profitable, ignoring search costs.
Add items till the profit of adding items is less than the average cost of searching and handling items currently in the diet.
What mussles do crabs like? [1]
Big mussles, to the point they ignore small abundant ones.
Profit of item = E2/H2 >= E1/S1+H1
What does this mean? [1]
This means the profit of a new item must surpass the cost of item 2 while searching for the new item (aka item 1).
E= ENERGY PROVIDE H = HARVEST EFFORT S = SEARCH COSTS
