Lecture 5 + 6 - Predation

Question 1

What is competition theory? [1]

Answer 1

Exponential growth - Intraspecific competition - Interspecific competition.

Question 2

What is an equation for a line in competition theory? [1]

Answer 2

N1 = K1 - α12N2

K1 - Intercept [intraspecific]

α12 - Gradient
[interspecific K adjustment]

Question 3

What happens ‘on the line’ of a population growth size graph between two species? [1]

Answer 3

On the line, means there is zero population growth.

As everything goes ‘towards the line’.

Question 4

What’s the difference of a competitive exclusion graph? [1]

Answer 4

The species isoclines don’t cross, so the species with the largest K should eventually outocmpete the other.

Question 5

What is intraspecific equilibrium? [1]

Answer 5

When individuals coexist where Births = Deaths

Question 6

What happens in coexistence in terms of isoclines? [1]

Answer 6

The isoclines cross and get pushed towards the same point.

Question 7

What happens in an unstable equilbrium in terms of isoclines? [1]

Answer 7

They get pushed towards different K’s, so eventually one species will outcompete the other.

Question 8

Give six examples of competition. [6]

Answer 8

Exploitation [resource depleetion]
Pre-emptive [using space]

Overgrowth [light deprivation]
Chemical [toxins]
Territorial [fighting]
Encounter [transient]

Question 9

What did Tansley 1917 investigate? [2]

Answer 9

Growth rates of G saxatile and G sylvestre under calcareous and acid soil types.

Question 10

What did Tansley 1917 conclude? [2]

Answer 10

Coexistence causing a reduction in abundance, but intraspecific competition must be stronger than interspecific.

Question 11

What did Park 1954/62 investigate? [1]

Answer 11

Competitive exclusion between two beetles, T. Confirsum and T cataneum.

Question 12

What did Park 1954/62 conclude? [2]

Answer 12

Complete competitive exclusion can happen in warm moist (benefitting T. cataneum) or cool dry (benefitting T. confirsum).

However, coexistance may occur in some temperatures.

Question 13

What did Connell 1961 investigate and conclude? [1]

Answer 13

That Chtamalus and Balanus barnacles can coexist but still compete against each other.

Question 14

What is allopatric speciation? [1]

Answer 14

Geographical separation causing speciation.

Question 15

What is sympatric speciation? [1]

Answer 15

Speciation occuring within the same geographical area.

Question 16

What did Crombie 1941 study? [1]

What did he conclude? [1]

Answer 16

Rhizopertha and Sitoraga

He concluded coexistance.

Question 17

How may a caterpillar prevent plant resource defence? [1]

Answer 17

They can eat around the leaf in a circle, spitting stuff to prevent plant defence.

Question 18

Why zebra stripey? [1]

Answer 18

Because suggested disease defence.

Question 19

What’s batesian mimicry?

Answer 19

Normo mimics a harmful model

Question 20

What’s Mullerian mimicry?

Answer 20

Two unpalatable mimics mimic each other

Question 21

What is the contingency model of foraging? [2]

Answer 21

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.

Question 22

What mussles do crabs like? [1]

Answer 22

Big mussles, to the point they ignore small abundant ones.

Question 23

Profit of item = E2/H2 >= E1/S1+H1

What does this mean? [1]

Answer 23

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