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David M Wilkinson

Publications and source records attributed to David M Wilkinson.

4 recordsLinked to original sources
PubMed2005

Explaining Dioscorides' "double difference": why are some mushrooms poisonous, and do they signal their unprofitability?

The adaptive significance of toxins in mushrooms has received very little consideration, although it is clear that poisons have appeared (and/or disappeared) many times in mushrooms' evolutionary history. One possibility is that poisons have evolved in some mushroom species to deter their consumption by would-be fungivores before spore dispersal. If this is so, then one might expect poisonous mushrooms to signal their unprofitability in some way. In this study, we have conducted the first formal analysis of the ecological and morphological traits associated with edible and poisonous mushrooms in North America and Europe. Poisonous mushrooms do not tend to be more colorful or aggregated than edible mushrooms, but they are more likely to exhibit distinctive odors even when phylogenetic relationships are accounted for. This raises the intriguing possibility that some poisonous species of mushrooms have evolved warning odors (and perhaps tastes) to enhance avoidance learning by fungivores.

Agaricales↗
PubMed2004

Red leaves, insects and coevolution: a red herring?

W.D. (Bill) Hamilton proposed that coevolution between plants and herbivorous insects explains the bright autumnal colouration of leaves. Accordingly, plants invest in bright signals to reduce their herbivore load, whereas insects use these bright signals to identify less-defended hosts more efficiently. Archetti and Brown have recently revisited this theory by explaining its basic predictions and providing new research perspectives. Their work presents an important basis to our understanding of non-green leaf colouration, provided that alternative adaptive explanations on the photoprotective and antioxidant role of leaf pigments, or their possible function in crypsis to herbivores are incorporated into future research.

Journal Article↗
PubMed2003

The fundamental processes in ecology: a thought experiment on extraterrestrial biospheres.

Ecological science is often organised as a hierarchical series of entities: genes, individuals, populations, species, communities, ecosystems and biosphere. Here, I consider an alternative process-based approach to ecology, and analyse the nature of the fundamental processes in ecology. These fundamental processes are discussed in the context of the following question: 'for any planet with carbon-based life, which persists over geological time scales, what are the minimum set of ecological processes that must be present?' I suggest that the following processes would be present on any such planet: energy flow, multiple guilds, ecological trade-offs leading to within-guild biodiversity, ecological hypercycles, merging of organismal and ecological physiology, carbon sequestration and possibly photosynthesis. Nutrient cycling is described as an emergent property of these fundamental processes. I discuss reasons why a biosphere based on a single species with no nutrient cycling is very unlikely to exist. I also describe the concept of 'Gaian effect'. This suggests that some processes will always tend to extend the lifespan of a biosphere in which they develop (positive Gaian effect) while others could either increase or decrease (negative Gaian effect) such a lifespan. These ideas are discussed in the context of astrobiology, ecosystem services, conservation biology and Gaia theory.

Animals↗