Table 1

Possible outcomes (rows, columns) of a cross-infection experiment where parasite performance is assayed, both, on coevolved host populations, and on control host populations paired for the same original host lines.

Control host populations

Outcomes:

Mortality in matching combinations > non-matching combinations

Mortality in matching combinations < non-matching combinations

No difference between matching and non-matching combinations


Mortality in matching combinations > non-matching combinations

1: Parasite adaptation

2: Parasite maladaptation < host maladaptation

3: Host maladaptation

Coevolved host populations

Mortality in matching combinations < non-matching combinations

4: Parasite adaptation < host adaptation

5: Parasite maladaptation

6: Host adaptation

No difference between matching and non-matching combinations

7: Parasite adaptation = host adaptation

8: Parasite maladaptation = host maladaptation

9: No adaptation


The numbered entries refer to the interpretation for each possible combination of outcomes a. A matching combination refers to hosts and parasite being from the same experimental coevolution replicate; non-matching otherwise.

a Differentiating between parasite adaptation and host maladaptation can be facilitated if parasite fitness is assayed on replicate host populations of identical genetic background as their coevolving antagonists. In this table we have used host mortality as a measure of both parasite and host performance, as these traits are very closely linked to fitness in both antagonists in our study system [39,41]. For other study systems, relevant traits may differ. This experimental approach has, to our knowledge, never been used, but could most readily be performed in a laboratory setting.

Bérénos et al. BMC Evolutionary Biology 2012 12:11   doi:10.1186/1471-2148-12-11

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