Host + parasites (DONE)

Question 1

What defines host-parasite interactions?

Answer 1

Host-parasite interactions involve one organism (the parasite) benefiting at the expense of the host, w long lasting coevolution

Question 2

What is the key difference between host-parasite interaction & predator-prey interactions?

Answer 2

Host-parasite interactions are long-lasting & involve close coevolution

While predator prey interactions are short-term & often lethal for the prey

Question 3

What is virulence (in the context of host-parasite relationships)?

Answer 3

Virulence refers to the damage caused by a parasite to its host

Question 4

How do parasites evolve to optimise virulence?

Answer 4

Parasites balance exploiting the host w the need for transmission (not killing the host)

Often stabilising virulence over time

Question 5

What happened w the Myxomatosis virus in Australian rabbits?

Answer 5

Over time, the Myxomatosis virus decreased in virulence, stabilising at an optimal level to ensure host survival for transmission

Question 6

What is horizontal transmission in parasites?

Answer 6

Horizontal transmission occurs when parasites spread between individuals in the same generation

This is often associated w higher virulence

Question 7

What is vertical transmission in parasites?

Answer 7

Vertical transmission occurs when parasites are passed from parent to offspring

Often associated w lower virulence

Question 8

How does Wolbachia in woodlice affect virulence?

Answer 8

Wolbachia inc virulence when horizontal transmission in enforced in experimental settings

Question 9

What are examples of diseases w lower virulence compared to vector-borne diseases?

Answer 9

Directly transmitted diseases typically have lower virulence compared to vector borne diseases (e.g. malaria)

Question 10

What is the Red Queen Hypothesis?

Answer 10

The Red Queen Hypothesis suggests that both host & parasite are in a constant evolutionary race to adapt & counter-adapt

Question 11

How do rare host genotypes relate to parasitism in the Red Queen Hypothesis?

Answer 11

Rare host genotypes initially escape parasitism

But as they become more common, parasites adapt to exploit them

This creates a continuous cycle

Question 12

What is an example of the Red Queen Hypothesis in New Zealand snails?

Answer 12

Common clones of NZ snails show higher infection rate by lake-specific parasites

Supports the Red Queen Hypothesis

Question 13

How does the Daphnia & Pasteuria experiment support the Red Queen Hypothesis?

Answer 13

Experiments w past & present pops of Daphnia & Pasteuria demonstrate temporal genotype cycling, consistent w the hypothesis

Question 14

What is a host-trade off in the context of resistance?

Answer 14

Hosts face trade-offs between investing in resistance to parasites & other fitness traits like reproduction

Question 15

How does resistance to parasites affect Drosophila’s reproduction?

Answer 15

Drosophila genotypes w higher resistance to parasites often show reduced fecundity

Question 16

How does resistance to parasites affect fish?

Answer 16

In fish, resistance to parasites is often negatively correlated w tolerance, indicating a cost in dealing w infections

Question 17

What is the geographic mosaic of coevolution?

Answer 17

Host-parasite interactions vary geographically due to local adaptations & environmental conditions

Question 18

How do sticklebacks & parasites illustrate geographic mosaic coevolution?

Answer 18

In sticklebacks, parasite virulence & host resistance are influenced by water chemistry, w alkaline environments supporting higher parasite virulence

Question 19

What defines a diffuse arms race in convolution?

Answer 19

Diffuse arms races involve multiple host & parasite species interacting simultaneously

Leads to complex coevolutionary dynamics

Question 20

What is an example of a diffuse arms race?

Answer 20

Cuckoo-host interactions, where cuckoo eggs mimic host eggs & hot birds evolve egg rejection behaviours

Question 21

How do cuckoos adapt to host defences?

Answer 21

Cuckoos use egg mimicry, distract host parents w sparrow hawk-like cries & lay eggs rapidly to avoid detection

Question 22

How do hosts counter cuckoo parasitism?

Answer 22

Hosts evolve egg rejection behaviours, identifying & removing foreign eggs

Question 23

Why do Icelandic birds show lower rejection rates for cuckoo eggs?

Answer 23

Icelandic birds show lower rejection rates due to the lack of cuckoo parasitism in their environment

Question 24

How does the size of host & cuckoo species correlate?

Answer 24

Larger hosts tend to support larger cuckoos, w adaptations aligning across species

Question 25

What is egg ejection in cuckoo-host interactions?

Answer 25

Egg ejection occurs when cuckoos eject host eggs to monopolise parental care, typically in species w smaller hosts & cuckoos

Question 26

What genetic factors are involved in cuckoo-host interactions?

Answer 26

Egg mimicry & host preference are likely linked to genes on the W chromosome –> allowing maternal inheritance of these traits

Question 27

How can host-parasite studies inform human disease research?

Answer 27

Understanding transmission modes can predict virulence trend in disease like cholera & other waterborne diseases

Question 28

What ecological insights are gained from host-parasite studies?

Answer 28

Host-parasite dynamics drive biodiversity & evolutionary innovation across ecosystems

Question 29

How does studying host-parasite coevolution contribute to broader scientific understanding?

Answer 29

It proves insights into evolutionary strategies, the balance of fitness traits & the dynamics of ecological interactions

Question 30

What role does parasite host dynamics play in ecosystems?

Answer 30

Parasite-host dynamics help shape biodiversity, influence evolutionary processes & contribute to the functioning of ecosystems