Đâu có acc đâu mà đọc cái article của a. Nếu a có acc inbox cho e dùng với, dạo này học xong nên trường cắt hết mấy cái acc xem journal rồi
Liệu đoạn giới thiệu này của họ có thuyết phục không nhỉ? Về mặt kỹ thuật tớ không có đánh giá gì được vì kiến thức về di truyền học đã trở về lại gần zero rồi
The assessment of species distribution is a first critical phase of biodiversity studies and is necessary for several disciplines such as biogeography, conservation biology and ecology (Margurran 2004). However, several species are difficult to detect, especially during particular time periods or developmental stages, potentially biasing study outcomes (Gotelli & Colwell 2001; MacKenzie et al. 2006). The extraction of DNA from environmental samples allows the characterization of their micro-organisms (Venter et al. 2004). It can also provide information on extinct communities of macro-organisms, since short DNA sequences can persist for long time periods, as shown by the studies on old sediments, permafrost and ice cores (Hofreiter et al. 2003; Willerslev et al. 2003, 2007). While short DNA sequences may be present at high density in the environment, their potential for the study of present-day communities of macro-organisms remains substantially unexplored. Here we present a novel approach, based on the persistence of DNA in the environment, to detect the presence of a species in fresh water. We examined whether DNA fragments are preserved in the aquatic environment and whether they can be used for a reliable assessment of current species presence. We first used the method in controlled environments and then evaluated whether it could be applied under natural field conditions. The model species was the American bullfrog Rana catesbeiana (=Lithobates catesbeianus), an invasive amphibian for which high-quality census data exist (Ficetola et al. 2007a,b). This allowed reliable field validation. The American bullfrog is native to western North America, but has been introduced into ecosystems around the globe. It is considered one of the world's most harmful invasive species, since it is responsible for the decline of native amphibians by direct predation, competition, diffusion of diseases and complex biotic interactions (Blaustein & Kiesecker 2002; Kats & Ferrer 2003; Garner et al. 2006).
