Predation (DONE)

Question 1

Define predatory-prey interactions:

Answer 1

The ecological relationships & dynamics between predators & their prey

These interactions are a fundamental aspect of ecosystems - have effects on population dynamics, community structure & evolutionary processes

Question 2

What are some examples of possible evolutionary outcomes of predator-prey interactions?

Answer 2

• Camouflage of prey = increased visual acuity of predators
• Escape speed = speed of pursuit
• Flocking & herding = counterstrategies (e.g. picking the slowest, oldest, weakest etc from the grp)
• Predator avoidance = trickery (e.g. mimicry)

Question 3

What are the general predictions of predator-prey interactions?

Answer 3

• If predator invests –> greater avoidance by prey
• If prey invests –> predator not respond bc, e.g. prey density inc (cancels cost to predator)

Question 4

What did Abrahams (2000) say about trade-offs in predator-prey interactions?

Answer 4

Investments by predators or prey (e.g. running speed) reduced other aspects of fitness

(e.g. thin bones break, lean bodies starve)

Question 5

What is the main driver of adaptations in predator-prey interactions?

Answer 5

Coevolution, where adaptions in one species drive counter-adaptations in the other

Question 6

What are some examples of predator prey strategies?

Answer 6

1 - Prey selection by predators –> Targeting the weakest (e.g. slowest or youngest individuals)

2 - Prey mimicry –> species like Rhagoletis pomonella mimic predators (e.g. spiders) to avoid being eaten

Question 7

What is a coevolutionary arms race?

Answer 7

An escalating evolutionary process where predators & prey develop adaptations to outcompete each other

Question 8

What is an example of a coevolutionary arms race?

Answer 8

Ungulates & carnivores

Ungulates evolved faster running speeds, forcing carnivores to improve hunting strategies & brain size

Question 9

Case Study: Toxin Resistance in Newts and Snakes

How do newts protect themselves from predators?

Answer 9

They produce tetrodotoxin (TTX), a neurotoxin that paralyses predators by blocking sodium channels

Question 10

Case Study: Toxin Resistance in Newts and Snakes

How have snakes (e.g. garter snakes) adapted to newt TTX?

Answer 10

1. Evolved mutations in sodium channels that resist TTX
2. Resistance incurs geographical trade-offs
   –> Northern populations: minimal cost
   –> Southern populations: reduces crawl speed due to resistance

Question 11

Case Study: Toxin Resistance in Newts and Snakes

What experimental evidence links snake resistance to fitness trade-offs?

Answer 11

Resistant snakes exposed to TTX showed slower movement, demonstrating the cost of resistance

Question 12

Case Study: Moths and Bats

What is echolocation & how to bats use it?

Answer 12

Echolocation involves emitting sound waves & analysing echoes to locate prey

Question 13

Case Study: Moths and Bats

What are moth counter-adaptions to bat echolocation?

Answer 13

1. Stealth coating = reduces sound reflection
2. Sound detection = evolved “ears” to detect bat echolocation
3. Evasive flight = faster, tighter manoeuvres to escape
4. Jamming sonar = some moths emit sounds to interfere w echolocation (e.g. Trigona moths)

Question 14

Case Study: Moths and Bats

How do bats counter adapt to moth defences?

Answer 14

1= Quieter echolocation calls (“whispering”)

2 = Modified calles for broader detection ranges

Question 15

What is aposematic signalling?

Answer 15

Warning signals (e.g. bright colours or sounds) by unpalatable moths to deter predators

Question 16

What is Batesian mimicry?

Answer 16

Palatable moths mimic unpalatable species to avoid predation

Question 17

How do silk moths tails create sensory illusions?

Answer 17

Long tail streamers divert bat attacks away from vital body parts

Question 18

What experimental evidence supports the role of long moth tails?

Answer 18

Longer tails increased the likelihood of escaping bat attacks

Question 19

How does geographic variation affect coevolutionary dynamics?

Answer 19

Local conditions (e.g. toxin levels in newts) drive variation in predator-prey adaptations

Question 20

What are cost-benefit trade-offs in predator-prey adaptations?

Answer 20

Adaptations like resistance or evasive flight often incur fitness costs, such as reduced speed or efficiency

Question 21

How do sensory adaptations evolve in predator-prey interaction?

Answer 21

• Predators (e.g. bats) evolve echolocation
• Prey (e.g. moths) develop sound detection or stealth adaptations

Question 22

What evidence supports coevolution between newts & snakes?

Answer 22

1 - Correlation between newt toxicity & snake resistance

2 - Resistance linked to mutations in sodium channels

Question 23

What evidence supports bat-moth dynamics?

Answer 23

1 - Removing moth fluff increased sound reflection, confirming stealth function

2 - Longer moth tails resulted in more missed bat attacks

Question 24

What factors influence predation escape probability?

Answer 24

Speed, agility & sensory countermeasures

Question 25

(Need to check if this formula is actually needed)

What is the formula for fitness trade-offs in adaptations?

Answer 25

Fitness = B - C

Where B = survival benefits & C = cost of adaptation

Question 26

Summary:

What do predator-prey interactions demonstrate?

Answer 26

The dynamic coevolution of species thru adaptations & counter-adaptations, driving biodiversity & ecological balance