Pressing the upper button you will have acces to the groups of life present in the collection. Starting from higher rank groups, you can go down to lower taxonomical groups until reach the species level. Throgought the way Domain→Kindom→Phylum→Class→Order→Species, you can watch the species of a determinated group of life. The lower text explains what are the taxonomical groups and how to search in the collection.

        Domain/Kingdom/Phylum/Class/Order/Family/Genus/Species

What are the taxonomical groups?

Actually more than two millions of species are known, and it is expected that exist some more millions. Given this number of species, with so different biological patterns, biologists are forced to put some order, classifying them in groups. The branch of biology responsible for classifying living organisms is called taxonomy. During the history of taxonomy, organisms were classified based on different characteristics, specially the morphology, but now groups are made gathering related evolutionary lineages. According to this, organisms that are under one group have been originated by evolution of a single common ancestor, or what is the same, the organisms that are more closely related are grouped. However the term "related" in taxonomy can be confusing, since very different organisms can reach the same morphology by independent paths, as happens on fishes, ichthyosaurs, sharks and whales, all fish-shaped, but originated by independent evolutionary lineages. The same is applied to insects, birds, bats and pterosaurs, all with wings originated independently.

These groups, which consist of individuals who share a common ancestor, are called taxa. Taxa can gather individuals at high evolutionary levels, like the taxon vertebrates, or at lower evolutionary levels, like the taxon rodents. Thus taxa are organized hierarchically, and higher taxa contains lower subordinate taxa. In this organizational scheme, each group of organisms is a taxon, and the hierarchical level in which it is located is called taxonomic category. Similarly, in political geography, continent, country and community, would be taxonomic categories, while Europe, Spain and Madrid would be taxa. As in geography each hierarchical level has a name (country, community, province, town, street, house) taxonomic hierarchical levels called taxonomic categories also receive a name. From higuer to lower range, these names are: Domain, Kingdom, Phylum, Class, Order, Family, Genus and Species. Some of these categories are common in the society, as the kingdoms animal, plant, fungi, or orders like rodents, butterflies or beetles.

Thus the domain category has several kingdoms, each Kingdom several Phyla, each Phylum several classes, and so on. Occasionally these categories are also divided into subcategories, for example superfamily, family, subfamily, or species, subspecies, variety. Each taxon has a name that refers to it, and this name must be in Latin or Latinized. In the case of the category species, each taxon has two names, such as Homo sapiens (man), Canis lupus (wolf) Mus musculus (mouse), the first name is the same as the category Genus, operating in the same way like in persons, with a name and a surname.

So when comparing two species, when more taxa possess in common, more closely related they are. As shown in the following example:

Domain: Eukaryota.
Kingdom: Animalia.
Phylum: Chordata.
Class: Mammalia.
Order: Primates.
Family: Hominidae.
Genus: Homo.
Species: Homo sapiens.

Domain: Eukaryota.
Kingdom: Animalia.
Phylum: Chordata.
Class: Mammalia.
Order: Rodentia.
Family: Muridae.
Genus: Mus.
Species: Mus musculus.

The first case is the classification of the human species, and the second, the house mouse. We see that we share the same Kingdom (both are animals), the same class (both are mammals), but in the level of order we are separated, because we are primates and mouses are rodents.

How to search in the collection?

The digital version of the collection contains the same species as the physical collection. On this web, species are ordered in the taxonomical groups of life, these groups are hierarchical and gather the subgroups according to its kinship. Pressing the button named Start Searching in the Collection you will access to the taxonomical category of Domain, which contains the groups of bacterias, eukariotes and archaeans. Selecting for example the eukariotes domain you will go to the Kingdom level, which contains animals, plants, fungi, ... If you select the animal Kingdom, you will reach the Phylum level, which contains vertebrates, arthropods, molluscs, … So by this way you are drived to a specific group of life, and then you can watch all the species of this group.

In each taxonomical group, some pictures and a description of the group are showed. By this web you can navigate through the tree of life until reach the order level, which is for xample the level of beetles, frogs, crabs or butterflies. Once in one order, species present in the collection are showed with pictures, descriptions and collecting sites.