Mimicry

Question 1

What is mimicry?

Answer 1

The resemblance of one organism to another or to an object in its surroundings for concealment and protection from predators
The similarity of one species to another that protects one or both
Mimics occur in the same areas as their models
Similarity in appearance, behaviour, sound or scent

Question 2

Give an example of behavioural mimicry

Answer 2

Black racer snake (Coluber constrictor) exhibits batesian mimicry, rattling its tail like a rattle snake despite being non-venomous

Question 3

Give an example of sound mimicry

Answer 3

Carrion beetle (Necrophilia americana) mimics Bombus spp. with regards to buzzing noise to deter predators (Fisher & Tuckerman, 1986) - also shows behavioural and appearance mimicry towards these spp.

Question 4

Give an example of scent mimicry

Answer 4

Wild orchard wasp mimic (Ophyrs spp.) tricks wasps by using chemical scent to lure them into the flower (mating scent)

Question 5

What are the three major categories of mimicry?

Answer 5

Defensive (majority)
Aggressive
Reproductive

Question 6

What are the types of defensive mimicry?

Answer 6

Batesion mimicry
Mullerian Mimicry
Auto-mimicry/Self Mimicry

Question 7

What is Batesion Mimicry?

Answer 7

Bates 1862
Mimic shares signals similar to the model but doesn’t have the attributes that make it unprofitable to predators
mimic resembles unpalatable/harmful species to avoid predation
No defence other than mimicry

Question 8

Example of Batesian mimicry

Answer 8

hoverfly spp. mimic waps/bees and bumble bees via colouration

Question 9

What is Mullerian mimicry?

Answer 9

2 or more poisonous/unpalatable species closely resemble each other therefore being avoided equally by predators
mutually beneficial
In same habitat, co-mimics more appropriate

Question 10

Give an example of Mullerian mimicry

Answer 10

Heliconius spp. exhibit similar wing patterns dependent on habitat both being unpalatable in each area therefore Mullerian mimicry (Meyer 2006)

Question 11

What is auto-mimicry/self-mimicry/intraspecific mimicry?

Answer 11

Mimicry occurring between members of the same species (males mimicing females or vice versa)
Or when one part of an organisms body resembles another body part

Question 12

Give an example of auto-mimicry

Answer 12

Gray hairstreak butterfly (Strymon melinus) has false head at rear which is held upwards at rest

Question 13

What is aggressive mimicry?

Answer 13

Where predators share the same characteristics as a harmless species allowing them to avoid detection by prey

Question 14

Give examples of aggressive mimicry

Answer 14

Angler Fish Lophiiformes spp)

Ant carcass assassin bug (Acanthaspis petax) (may also be defensive)

Question 15

What is host-parasite mimicry?

Answer 15

Parasite mimics host (brood parasitism in cuckoos - lay eggs looking like host eggs)

Question 16

What is reproductive mimicry?

Answer 16

Dupe directly aids the mimics reproduction (orchid pollination and brood parasitism)

Question 17

What is aposematism?

Answer 17

Generally bright and conspicuous, easy to learn e.g. wasps

predator learns species is unpleasant

Question 18

What impact does Batesian mimicry have on aposematism?

Answer 18

Hurts the model when frequency of mimics becomes high

Question 19

How can several sophisticated mimics exist in an interbreeding population without “dilution” of the mimicry patterns?

Answer 19

Each instance of mimicry must have evolved over a period of time, involving many modifying genes
Most unlikely that a modifier in one form would also increase the effectiveness of the mimicry in another form
The answer involves 2 basic concepts in the consideration of balanced polymorphisms
- super gene concept
- switch gene concept

Question 20

What is the super-gene concept?

Answer 20

More complex forms of polyphenism are controlled by supergenes consisting of several tightly linked genes on a single chromosome.
A group of neighbouring genes on a chromosome which are inherited together because of close genetic linkage and are functionally related in an evolutionary sense
Supergenes immune to sexual recombination, genes within the supergene switch places to create different morphs (Heliconius spp. for example) (Joron et al., 2006)

Question 21

What is the switch gene concept?

Answer 21

Controls the expression of the super genes

Decides which morph an individual displays: can be genetic or environmental