1,721,249 research outputs found
Biodiversity, taxonomy and metagenomics
Full text linkGenBank (Benson et al. 2013) is a database that
contains genetic sequences of species. Godfray
(2007) proposed that metagenomics can replace taxonomy
in identifying specimens. Indeed, giving
names to specimens is not the primary role of taxonomy,
the discipline being devoted to the description
of new species and to reconstruction of
phylogenies, focusing on both genotypes and phenotypes.
So, the use of metagenomics for routinary
species identification is a welcome technological aid
to the study of biodiversity, freeing taxonomists from
the burden of sorting and identifying biological
material
Refugia-within-refugia: the case of Podarcis muralis (Laurenti, 1768) in the Italian Peninsula
No full textEvolution of sex-chromosome in lacertid lizards.
No full textThe occurrence and form of sex chromosomes were investigated with the aid of C-banding and 4-6-diamidino-2-phenylindole (DAPI) staining in 13 species of lacertid lizards. The results obtained show the presence in five species of a female heterogamety in which the two sex chromosomes have the same shape and size, but the W differs from the Z in being almost entirely heterochromatic. This condition is clearly similar to that found in some snakes and considered to be an early stage of differentiation of sex chromosomes by Singh et al. (1976, 1980). A more evolved condition may be that found in three other species in which the W is distinctly smaller than the Z. A third situation is that found in all Podarcis species which, even though they are considered to be among the more evolved species in the family, possess two sex chromosomes that are indistinguishable. In general, the situation in lacertids may be compatible with the hypothesis of sex chromosome evolution put forward by Singh et al. (1976, 1980). However a differentiation mechanism of this kind does not seem to be well established in lacertids, and is probably not the only mechanism that is in operation in this family
- …
