species

Examples of species in the following topics:

• Newly Discovered Eukaryotes

  • There are many new species to be discovered, including eukaryotic species.
  • The vast majority of Earth's species are microbial.
  • However, as suggested above most of the attention is given to large species, which represent a very small portion of the new species identified Even with this in mind, since the beginning of this century, 5 marsupial species, 25 primate, 1 elephant, 1 sloth, 3 rabbit, several rodent species, at least 30 new bat species have been discovered.
  • Many extant species may become extinct before they are described.
  • This graph shows how many species discovered (dark green) versus estimated species remaining to be discovered.

• The Species Concept in Microbiology

  • The number of species of bacteria and archaea is surprisingly small, despite their early evolution, genetic, and ecological diversity.
  • The reason for this numerical peculiarity lies in the differences in species concepts between the bacteria and macro-organisms and in the difficulties in growing and characterizing in pure culture (a prerequisite to naming new species, vide supra).
  • It has been noted that if this were applied to animal classification the order of Primates would be considered a single species.
  • If the information is correct, the new species will be featured in the Validation List of IJSEM.
  • A genus contains one or more species.

• Unclassified and Uncultured Bacteria

  • To classify a species of bacteria, one usually needs to isolate and grow up the species that is to be classified.
  • Classification seeks to describe the diversity of bacterial species by naming and grouping organisms based on similarities.
  • While these schemes previously allowed the identification and classification of bacterial strains, it was long unclear whether these differences represented variation between distinct species or between strains of the same species.
  • While there are several molecular tools that allow us to classify or distinguish different bacterial species, this is predicated on obtaining uni-species cultures of a given bacteria.
  • Following present classification, there are a little less than 9,300 known species of prokaryotes, which includes bacteria and archaea.

• Noncholera Vibrios

  • Several species of Vibro can cause food borne infection, usually associated with eating undercooked seafood.
  • Vibrio species are prevalent in estuarine and marine environments.
  • Seven species can cause food borne infections associated with seafood.
  • Vibrio species are facultative anaerobes that test positive for oxidase and do not form spores.
  • Four other species (V. mimicus, V. hollisae, V. fluvialis, and V. furnissii) can cause gastroenteritis.

• Genetic Engineering in Animals

  • Scientists are now capable of creating new species of animals by taking genetic material from one, or more, plants or animals, and genetically engineering them into the genes of another animal.
  • Finally, endangered animal species can be cloned, thus helping wildlife management in its goals of preserving wild populations of the earth's biological diversity, and by ensuring that endangered animals' genetic information will not be lost when the last of the species dies.
  • Natural animals are specifically adapted to a given environment and when science manipulates the genes of a few species in the ecosystem, the entire balance of the ecosystem might fall completely apart and cause an unknown number of natural animal species to grow extinct.
  • Patents give scientists a monopoly over their genetically engineered animal species, something before unheard of in modern economic systems.
  • Typically, animals could be owned, but never entire species.

• Genome Reduction

  • Genome reduction is the loss of genome size of a species in comparison to its ancestors.
  • Obligate endosymbiotic species are characterized by a complete inability to survive outside their host environment.
  • Common examples of species with reduced genomes include: Buchnera aphidicola, Rickettsia prowazekii and Mycobacterium leprae.
  • It is important to note, however, that some obligate intracellular species have positive fitness effects on their hosts.
  • Based on this model, it is clear that endosymbionts face different adaptive challenges than free-living species.

• Detecting Uncultured Microorganisms

  • Using metagenomics, the microbial constituents of the world can be identified by culturing each individual species.
  • Early studies have shown that the microbial life around us in the air, sea, and soil is very diverse and only a small fraction of the species are known.
  • These early studies focused on 16S ribosomal RNA sequences which are relatively short, often conserved within a species, and generally different between species.
  • Many 16S rRNA sequences have been found which do not belong to any known cultured species, indicating that there are numerous non-isolated organisms out there.
  • Rather than culturing a microbe, this approach takes a sample and identifies the different species in it by sequencing all the species simultaneously.

• Mutualism vs. Symbiosis

  • Symbiosis is any relationship between two or more biological species.
  • Mutualism: In mutualistic interactions, both species benefit from the interaction.
  • Gut bacteria in particular are very important for digestion in humans and other species.
  • Ectosymbiosis: a relationship in which one species lives on the outside surface of the other.
  • These categories can be paired with the above terms to better describe the species' interactions.

• Epsilonproteobacteria

  • All species of this class are, like all Proteobacteria, Gram-negative .
  • The Helicobacter genus belongs to the class Epsilonproteobacteria, order Campylobacterales, family Helicobacteraceae and already has more than 35 species.
  • Some species have been found living in the lining of the upper gastrointestinal tract, as well as the liver of mammals and some birds.
  • The most widely known species of the genus is H. pylori which infects up to 50% of the human population.
  • It also serves as the type species of the genus.

• The FISH Technique

  • Many bacteria, however, even well-known species, do not grow well under laboratory conditions.
  • FISH can also be used to compare the genomes of two biological species, to deduce evolutionary relationships.
  • Biofilms, for example, are composed of complex (often) multi-species bacterial organizations.
  • Preparing DNA probes for one species and performing FISH with this probe allows one to visualize the distribution of this specific species within the biofilm.
  • Preparing probes (in two different colors) for two species allows to visualize/study co-localization of these two species in the biofilm, and can be useful in determining the fine architecture of the biofilm.