منابع مشابه
Cryptoendolith alteration of Antarctic sandstone substrates: pioneers or opportunists?
Introduction: Lichen dominated cryptoendolithic communities from the Dry Valleys of Antarctica have been the subject of much research over recent years owing to their potential as analogues of Martian lifeforms. This is primarily owing to the stress tolerant nature of the microorganisms, remarkable adaptive achievements and the similarities between the Antarctic Dry Valley ecosystems and condit...
متن کاملEukaryotic opportunists dominate the deep-subsurface biosphere in South Africa
Following the discovery of the first Eukarya in the deep subsurface, intense interest has developed to understand the diversity of eukaryotes living in these extreme environments. We identified that Platyhelminthes, Rotifera, Annelida and Arthropoda are thriving at 1.4 km depths in palaeometeoric fissure water up to 12,300 yr old in South African mines. Protozoa and Fungi have also been identif...
متن کاملCryptoendolithic alteration of Antarctic sandstones: Pioneers or opportunists?
[1] The cryptoendolithic habitat of the Antarctic Dry Valleys has been considered a good analogy for past Martian ecosystems, if life arose on the planet. Yet cryptoendoliths are thought to favor the colonization of rocks that have a preexisting porous structure, e.g., sandstones. This may weaken their significance as exact analogues of potential rockcolonizing organisms on Mars, given our curr...
متن کاملRalstonia solanacearum and R. pseudosolanacearum on Eucalyptus: Opportunists or Primary Pathogens?
Ralstonia solanacearum and R. pseudosolanacearum are well known primary pathogens of herbaceous crops. Reports of wilt caused by these pathogens in tree species are limited other than on Eucalyptus species. Despite the widespread occurrence of so-called bacterial wilt on eucalypts in tropical and sub-tropical parts of Africa, Asia, and the Americas, there remain many contradictions relating to ...
متن کاملCoping with the extremes: stress physiology varies between winter and summer in breeding opportunists.
Seasonal changes in stress steroid hormone secretions are thought to reflect investment in self-maintenance versus reproduction. The capricious conditions hypothesis (CCH) posits that reduced corticosterone (CORT) secretion during stress coincident with parental phases of breeding is necessary in harsh environments because a full response would otherwise trigger repeated nest abandonments. To t...
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ژورنال
عنوان ژورنال: Nature
سال: 1980
ISSN: 0028-0836,1476-4687
DOI: 10.1038/286441a0