A review of systematics,distribution and ecology of tropical freshwater zooplankton

Studies on tropical freshwater zooplankton which commenced in the mid-19th century have been intensified during the past twenty years or so. The whole region, barring a few areas, has been investigated, including very recently tropical Australia. The widely scattered literature is briefly summarized with comments. Some general distributional patterns are emerging. There is a dearth of ecological studies especially on seasonality and production. Systematics lags behind the North Temperate zone in most tropical regions.     

Molecular systematics,historical ecology,and phylogeography of Halimeda (Bryopsidales)

Halimeda (Bryopsidales), a genus of calcified, segmented green seaweeds, abounds in reefs and lagoons throughout the tropics. To investigate phylogenetic, phylogeographic, and historic ecological relationships of the genus, the nuclear rDNA including the SSU and both ITS regions were sequenced. A maximum likelihood tree revealed the following: (1) there were anatomical and morphological synapomorphies for five well-supported lineages; (2) the last common ancestor of one lineage invaded sandy substrata; those of two other lineages established in wave-affected habitats, whereas the cenancestor of the remaining two lineages occupied sheltered rocky slopes. Yet, several species adapted to new habitats subsequently, resulting in several cases of convergence; (3) all lineages separated into Atlantic and Indo-Pacific daughters, likely resulting from the rise of the Panamanian Isthmus. Each daughter pair gave rise to additional convergent species in similar habitats in different oceans; (4) Halimeda opuntia, the only monophyletic pantropical species detected so far, dispersed from the Indo-Pacific into the Atlantic well after the closure event; (5) minor SSU-sequence differences across species and phylogeographic patterns of vicariance indicated a relatively recent diversification of the extant diversity. Cretaceous and Early Tertiary fossil look-alikes of modern species must then have resulted from iterative convergence.     

《昆虫学年评》第33卷

<正> 本卷共ⅹⅱ+550页,收入23篇文章,依次为:杂交细胞瘤库(hybridoma libraries)在研究果蝇遗传及发育中的作用;IPM实施过程的估价;昆虫机械感受器的传导机制;蛾类的听觉、防卫及通讯;食针叶树的卷叶蛾属 Choristoneura昆虫的性外激素及行为学;蓟类植物昆虫区系的进化和生态;虎甲的生物学;神经毒剂对昆虫行为的亚致死影响;医学病毒属 Phlebrovirus的病毒及其传毒者;大气结构和运动对昆虫迁飞的影响;半翅目昆虫的化学生态学;温室害虫的生物防     

Towards a conceptual and operational union of bacterial systematics, ecology, and evolution

To completely understand the ecology of a bacterial community, we need to identify its ecologically distinct populations (ecotypes). The greatest promise for enumerating a community's constituent ecotypes is held by molecular approaches that identify bacterial ecotypes as DNA sequence clusters. These approaches succeed when ecotypes correspond with sequence clusters, but some models of bacterial speciation predict a one-to-many and others a many-to-one relationship between ecotypes and sequence clusters. A further challenge is that sequence-based phylogenies often contain a hierarchy of clusters and subclusters within clusters, and there is no widely accepted theory to guide systematists and ecologists to the size of cluster most likely to correspond to ecotypes. While present systematics attempts to use universal thresholds of sequence divergence to help demarcate species, the recently developed 'community phylogeny' approach assumes no universal thresholds, but demarcates ecotypes based on the analysis of a lineage's evolutionary dynamics. Theory-based approaches like this one can give a conceptual framework as well as operational criteria for hypothesizing the identity and membership of ecotypes from sequence data; ecology-based approaches can then confirm that the putative ecotypes are actually ecologically distinct. Bacterial ecotypes that are demonstrated to have a history of coexistence as ecologically distinct lineages (based on sequence analysis) and as a prognosis of future coexistence (based on ecological differences), are the fundamental units of bacterial ecology and evolution, and should be recognized by bacterial systematics.     

Molecular systematics, zoogeography, and evolutionary ecology of the atlantic parrotfish genus Sparisoma

Parrotfishes of the genus Sparisoma (Scaridae) are ecologically important tropical reef fishes restricted to the Atlantic Ocean. We investigated phylogenetic relationships among the eight extant species within this genus using mitochondrially encoded 12S and 16S ribosomal genes. Our molecular data support the view that (i) Sparisoma originated approximately 14-35 million years ago (mya), probably in the tropical western Atlantic, off Brazil; (ii) there have been at least four discrete bouts of cladogenesis within the genus, with the most recent one ( approximately 2.8-5.6 mya) involving four events in both the east and the west Atlantic and across the Atlantic; and (iii) the genus invaded the eastern Atlantic on two different occasions, probably by at least two different routes. The data also offer support for Bellwood's ideas concerning the evolutionary changes in adult feeding patterns and habitat use within Scarids. Specifically, they support the evolutionary position of the ecological traits of Sparisoma as intermediate within the family.     

Plant Epigenetics. Annual Plant Reviews, Volume 19

Recently there have been remarkable advances in our understandingof epigenetic mechanisms in plants. Given the rapid increasein publication of scientific papers involved in plant epigenetics,a book that provides comprehensive coverage of recent knowledgeis earnestly