Biology Reference
In-Depth Information
naïve predators and better protection against experienced predators through more
detectable and memorable warning signals. Aposematism has promoted the evolution
of both Müllerian mimicry (repellent species look alike) and Batesian mimicry (palatable
species mimic noxious species).
Prey defences are costly and involve trade-offs in both their production and use.
Experiments with guppies reveal that male colouration reflects a balance between the
advantages of bright colours for mating and dull colours for avoiding predation.
Cuckoo-host interactions involve coevolution of cuckoo tricks to get their eggs and
chicks accepted by hosts and of host defences to reject them. Field experiments reveal
the successive stages of coevolution.
Further reading
We have not attempted to give a comprehensive review, rather to take a few well-defined
problems and to show how these can be tackled by field and laboratory experiments.
A wonderful review of predator-prey interactions is given in the topic by Ruxton,
Sherratt and Speed (2004). Animal camouflage is reviewed in the issue of the
Philosophical Transactions of the Royal Society, edited by Stevens & Merilaita (2009).
Mappes
et al
. (2005) review aposematism. Marshall (2000) shows that conspicuous
colours in reef fishes can sometimes look cryptic from a distance. Mallet and Joron
(1999) review warning colours and mimicry. Rowland
et al
. (2007) test by experiment
whether there is a mutualistic or a parasitic relationship between unequally defended
co-mimic species. Darst
et al
. (2006) compare investment in warning signals and
toxicity in poison frogs.
Krüger (2011) shows how acceptance of a non-mimetic cuckoo egg can sometimes
be adaptive for hosts. Rothstein (2001) and Lahti (2005, 2006) consider what
happens to host defences after brood parasitism ceases. Davies (2011) compares
cuckoo adaptations involving 'trickery' (to beat host defences) and 'tuning' (to
improve host care through tuning into host life histories). Hauber
et al
. (2006) show,
by experiment, how hosts vary their acceptance of foreign eggs in response to
parasitism threat.
The papers by Susanne Foitzik and colleagues explore the antagonistic interactions
between slavemaker ants and their hosts, and provide many interesting
parallels with cuckoo-host interactions (Foitzik & Herbers, 2001; Foitzik
et al
.,
2001, 2003). Kilner and Langmore (2011) compare cuckoo-host interactions in
birds and insects.
Buckling and Rainey (2002) is a classic demonstration of a coevolutionary arms
race, using laboratory cultures of a bacterium and a bacteriophage.
TOPICS FOR DISCUSSION
1.
Does grouping in prey promote the evolution of warning signals? (Read these three papers,
which provide contrasting views from a clever experimental design with a 'novel world' of
prey: Alatalo & Mappes, 1996; Tullberg
et al
., 2000; Riipi
et al
., 2001).
2.
In butterflies, eyespots may be signals for mate choice as well as for deterring predators
(read Robertson & Monteiro 2005). How would you investigate the influence of these two
selection pressures?
