Discussion of Phylogenetic Relationships

This is an excerpt from "The Tree of Life Web Project". It is guaranteed to put the large majority of you to sleep. Goodnight in advance.

The kingdom Fungi is a diverse clade of heterotrophic organisms that shares some characters with animals such as chitinous structures, storage of glycogen, and mitochondrial codon UGA encoding tryptophan. Both animals and fungi have spores or gametes with a single smooth, posteriorly inserted flagellum, but only species of the basal chytrid phyla have retained this primitive character (Barr, 1992; Cavalier-Smith, 1987, 1995). Fungi, animals, and other heterotrophic protist-like organisms such as choanoflagellates and Mesomycetozoea are now considered part of the larger group termed opisthokonts (Cavalier-Smith, 1987) in reference to the posterior flagellum.

The branch uniting the fungi and animals is well-supported based on a number of molecular phylogenetic datasets, including the nuclear small subunit ribosomal RNA gene (Wainwright et al., 1993; Bruns et al. 1993), unique and shared sequence insertions in proteins such as elongation factor 1α (Baldauf and Palmer, 1993), entire mitochondrial genomes (Lang et al., 2002), and concatenated protein-coding genes (Steenkamp et al., 2006). Read More » January 13th, 2008 / 35698 Comments / Tags: Daily Bore, science, biology, words

Syndesmology, Gray's Anatomy

The following is a selection of text about cartilage from Gray's Anatomy 1918. Hopefully you won't find this terribly interesting and it will put you to sleep quickly.

THE BONES of the skeleton are joined to one another at different parts of their surfaces, and such connections are termed Joints or Articulations. Where the joints are immovable, as in the articulations between practically all the bones of the skull, the adjacent margins of the bones are almost in contact, being separated merely by a thin layer of fibrous membrane, named the sutural ligament. In certain regions at the base of the skull this fibrous membrane is replaced by a layer of cartilage. Where slight movement combined with great strength is required, the osseous surfaces are united by tough and elastic fibrocartilages, as in the joints between the vertebral bodies, and in the interpubic articulation. In the freely movable joints the surfaces are completely separated; the bones forming the articulation are expanded for greater convenience of mutual connection, covered by cartilage and enveloped by capsules of fibrous tissue. The cells lining the interior of the fibrous capsule form an imperfect membrane—the synovial membrane—which secretes a lubricating fluid. The joints are strengthened by strong fibrous bands called ligaments, which extend between the bones forming the joint. Read More » January 13th, 2008 / 2145 Comments / Tags: science, words, medical