Nature 437, 1248 (27 October 2005) | doi: 10.1038/4371248a
Mycology: The whiff of danger
Tim Lincoln
You don't take the death cap (Amanita phalloides) home for tea. This species, pictured here, is infamously poisonous (có tính độc khét tiếng) , with many other mushrooms being toxic to a greater or lesser degree.
Thomas N. Sherratt, David M. Wilkinson and Roderick S. Bain have addressed (đào sâu, chuyên tâm) two issues raised (phát sinh) by the existence of poisonous mushrooms (Am. Nat. doi:10.1086/497399). The first question was what purposes possession of poisons might serve in mushrooms. One possibility is that toxins are simply a metabolic by-product (sản phẩm phụ của quá trình trao đổi chất). Another that has been suggested by several authors is that they act as a deterrent (rào cản) to predators (thú ăn thịt), which might otherwise destroy the mushroom before its spores (bào tử) have matured (trưởng thành) and dispersed (phát tán). Fungus-loving vertebrates (thú ưa nấm) could in particular be highly destructive.
An evolutionary principle (cơ sở tiến hóa) is that if you as an organism go to the bother of being unpalatable, you might as well signal that fact. Does this apply in mushrooms? To investigate this second issue, Sherratt et al. turned to data compilation and neural-network analysis. They made use of modern evolutionary trees to judge the incidence of poisonousness in mushrooms, then analysed data sets, culled from field guides, to see whether poisonous species tend to have particular ecological correlates — whether, for instance, they are more colourful, more aggregated or have a more noticeable odour.
Overall odour (and not cap colour) came out as the best predictor of toxicity, a result that was supported by pairwise comparisons of related poisonous and edible forms. Given that many animals forage by night, and that nocturnal mammals tend to have relatively poor colour vision, the authors suspect that odour provides the more effective signal.
Sherratt et al. make plain that their study is correlative only, and that — for them and others — this is a work in progress. There is rich scope for further investigation of the hypothesis that poisonous mushrooms use odours as warning signals, and of the likely exceptions.
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cả ngày đi nghiên cứu tính đa dạng của Algae, mệt rồi, mai làm tiếp.
Mycology: The whiff of danger
Tim Lincoln
You don't take the death cap (Amanita phalloides) home for tea. This species, pictured here, is infamously poisonous (có tính độc khét tiếng) , with many other mushrooms being toxic to a greater or lesser degree.
Thomas N. Sherratt, David M. Wilkinson and Roderick S. Bain have addressed (đào sâu, chuyên tâm) two issues raised (phát sinh) by the existence of poisonous mushrooms (Am. Nat. doi:10.1086/497399). The first question was what purposes possession of poisons might serve in mushrooms. One possibility is that toxins are simply a metabolic by-product (sản phẩm phụ của quá trình trao đổi chất). Another that has been suggested by several authors is that they act as a deterrent (rào cản) to predators (thú ăn thịt), which might otherwise destroy the mushroom before its spores (bào tử) have matured (trưởng thành) and dispersed (phát tán). Fungus-loving vertebrates (thú ưa nấm) could in particular be highly destructive.
An evolutionary principle (cơ sở tiến hóa) is that if you as an organism go to the bother of being unpalatable, you might as well signal that fact. Does this apply in mushrooms? To investigate this second issue, Sherratt et al. turned to data compilation and neural-network analysis. They made use of modern evolutionary trees to judge the incidence of poisonousness in mushrooms, then analysed data sets, culled from field guides, to see whether poisonous species tend to have particular ecological correlates — whether, for instance, they are more colourful, more aggregated or have a more noticeable odour.
Overall odour (and not cap colour) came out as the best predictor of toxicity, a result that was supported by pairwise comparisons of related poisonous and edible forms. Given that many animals forage by night, and that nocturnal mammals tend to have relatively poor colour vision, the authors suspect that odour provides the more effective signal.
Sherratt et al. make plain that their study is correlative only, and that — for them and others — this is a work in progress. There is rich scope for further investigation of the hypothesis that poisonous mushrooms use odours as warning signals, and of the likely exceptions.
=========
cả ngày đi nghiên cứu tính đa dạng của Algae, mệt rồi, mai làm tiếp.