منابع مشابه
Complement systems in invertebrates. The ancient alternative and lectin pathways.
The complement system in higher vertebrates is composed of about thirty proteins that function in three activation cascades and converge in a single terminal pathway. It is believed that these cascades, as they function in the higher vertebrates, evolved from a few ancestral genes through a combination of gene duplications and divergences plus pathway duplication (perhaps as a result of genome ...
متن کاملZoology: Invertebrates that Parasitize Invertebrates
The genome of an orthonectid, a group of highly modified parasitic invertebrates, is drastically reduced and compact, yet it shows the bilaterian gene toolkit. Phylogenetic analyses place the enigmatic orthonectids within Spiralia, although their exact placement remains uncertain.
متن کاملAncient carbon from a melting glacier gives high 14C age in living pioneer invertebrates
Glaciers are retreating and predatory invertebrates rapidly colonize deglaciated, barren ground. The paradox of establishing predators before plants and herbivores has been explained by wind-driven input of invertebrate prey. Here we present an alternative explanation and a novel glacier foreland food web by showing that pioneer predators eat locally produced midges containing 21,000 years old ...
متن کاملInvertebrates of ancient heavy metal spoil and smelting tip sites in southern Jordan: Their distribution and use as bioindicators of metalliferous pollution derived from ancient sources
The invertebrate populations of stony desert sites contaminated by ancient metalliferous activities in the Nabatean, Roman and Byzantine periods were significantly different from those found in adjacent ancient abandoned field systems. Consequently, it is apparent that such invertebrates potentially have uses as biomonitors of metalliferous pollution derived from ancient anthropogenic activitie...
متن کاملAquatic Invertebrates
Animals are important and conspicuous elements inPacifi c Island ecosystems. They are crucial to the fl ow of energy and nutrients within ecosystems and they strongly infl uence, and in some cases control, the species composition and population structure of communities. Determining which animal species are present in an area and what they do is crucial to understanding how ecosystems function a...
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ژورنال
عنوان ژورنال: Nature
سال: 1974
ISSN: 0028-0836,1476-4687
DOI: 10.1038/247408a0