An alternative population/genetics model for the evolution of egg mimesis and egg crypsis in cuckoos
| Autor: | M. G. Brooker, A. M. H. Brooker, L.C. Brooker |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Statistics and Probability
education.field_of_study General Immunology and Microbiology Host (biology) Applied Mathematics Population Population genetics Zoology General Medicine Biology biology.organism_classification General Biochemistry Genetics and Molecular Biology Chrysococcyx basalis Modeling and Simulation embryonic structures Crypsis Adaptation General Agricultural and Biological Sciences education Cuckoo Host specificity |
| Zdroj: | Journal of Theoretical Biology. 146:123-143 |
| ISSN: | 0022-5193 |
| DOI: | 10.1016/s0022-5193(05)80048-7 |
| Popis: | Cuckoos (Cuculinae) provide examples of a highly evolved host-parasite interaction where the parasite lays eggs adapted in colour and size toward those of its hosts. Egg colour adaptation in cuckoos could be either (a) a response to egg rejection behaviour on the part of the host or (b) the result of egg replacement by competing female cuckoos. We present a population/genetics model to describe the possible rates of spread of cuckoo egg mimesis and egg crypsis due to egg replacement. By combining this “replacement” model with a similar “rejection” model constructed by Kelly (1987, J. theor. Biol. 125, 283–299.) we explore the effect on cuckoo egg morphology of both selective agents operating at the same time. Our results show that the evolution of cuckoo egg mimesis and egg crypsis through egg replacement could have preceded and retarded the emergence of rejection behaviour in hosts. This would explain the apparent lack of rejection behaviour in two Australian cuckoo hosts whose parasites, Chrysococcyx basalis and Ch. lucidus , lay highly adapted eggs. Because rejection behaviour may, in fact, spread much more slowly through host populations than even the “rejection” model predicts, we suggest that egg replacement by competing female cuckoos is the more parsimonious explanation for egg morphology and host specificity in cuckoos and that the host-parasite interactions of Ch. basalis and Ch. lucidus are therefore probably homoeostatic. By comparing the Australian data with that from the northern hemisphere we show that observed differences between host species in rejection behaviour may reflect differences in the costs and benefits of rejection. This suggests that, in a host specific environment, rejection behaviour provides a stabilizing influence on the host-parasite interaction, proportional to each host's capacity to cope with the parasite. |
| Databáze: | OpenAIRE |
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