Euarchontoglires

A placental clade containing Primates and Glires, among other lineages.

Primates are a group of mammals including lemurs, monkeys and apes. Grasping appendages, sensory organization and social behavior vary substantially within the group. Features of one familiar species should not be treated as universal primate properties.

The rhesus macaque, Macaca mulatta, is an Old World monkey used in research on physiology, animal behaviour and neuroscience. Its importance as a model depends on the particular trait and comparison, not on an assumption of complete equivalence to humans.

A squirrel-monkey species used in tests of acquired colour discrimination after opsin addition.

A member of Hominoidea, comprising lesser apes and great apes. Living members do not exhaust the anatomical diversity of extinct apes.

A member of Hominidae, including Pongo, Gorilla, Pan and Homo. Living apes are evolved comparative relatives, not unchanged ancestral populations.

An extinct African hominin genus whose species combine different locomotor and feeding character mosaics.

A Pliocene hominin important to studies of the relationship between habitual bipedalism and retained climbing capabilities. Comparative analysis must account for age and growth. ^[ref]

An extinct African hominin genus, including Paranthropus boisei, with specialized masticatory anatomy.

An East African hominin with very large postcanine teeth and a robust feeding apparatus. dental microwear and enamel carbon-isotope evidence complicate a simple inference of habitual hard-object feeding from gross anatomy. ^[ref]

In the human-evolution usage adopted here, a member of the human lineage after its separation from Pan. Usage and formal tribal boundaries should be stated because classifications differ.

A Miocene fossil ape with a mosaic of trunk and hand characters. Its informative anatomy does not uniquely identify it as the Pan–Homo last common ancestor. ^[ref]

An African fossil ape genus including Ardipithecus ramidus, important to hypotheses about early hominin locomotion.

An approximately 4.4-million-year-old fossil hominin with an informative, incomplete skeleton. Its inferred locomotor mosaic differs from treating a living chimpanzee as an unchanged human ancestor. ^[ref]

Pongo is the genus of orangutans, great apes native to Southeast Asia. Their long forelimbs and arboreal behavior provide comparisons for studying locomotion and the diversity of the ape body plan.

Gorilla is a genus of African great apes. Comparison with other apes connects differences in feeding, locomotion and social organization to shared evolutionary ancestry. A genus-level description does not erase variation among species and populations.

The genus containing Homo sapiens and extinct related species.

An archaic human lineage first characterized genetically. Its contribution to some living populations illustrates a history more complex than complete replacement without interbreeding.

An extinct Eurasian human lineage known from fossils and Ancient DNA, with evidence of genetic admixture with ancestors of living people.

The living human species. Its population history includes African ancestral structure, dispersal, demographic change and genetic admixture.

The genus containing chimpanzees and bonobos, the closest living sister lineage of Homo.

The species Pan paniscus, sister to the chimpanzee within Pan. It is a living evolved lineage rather than an unchanged ancestral social model.

The species Pan troglodytes, distinguished from the bonobo. Within-species ecological and behavioural variation matters in comparative inference.

Colobinae are a group of Old World monkeys including colobus monkeys and langurs. Specialized foregut digestion supports use of fibrous plant material. This is a distinctive digestive organization within Primates, not a general feature of all monkeys.

A member of Colobinae, a primate lineage with specialized foregut fermentation.

Glires is the mammalian group joining Rodentia and Lagomorpha. Their shared ancestry is distinct from a merely ecological grouping of small plant-eating animals.

Lagomorpha is the mammalian group containing rabbits, hares and pikas. An additional small pair of upper incisors distinguishes its dentition from that of Rodentia, despite some similarities in feeding and appearance.

A lagomorph with specialized hindgut digestion and cecotrophy. It is not a member of Rodentia.

Rodentia is the mammalian group characterized by a single pair of continuously growing incisors in each jaw. Gnawing depends on the interaction between tooth growth and wear. Rats and the house mouse are familiar members.

Caviidae is a taxonomic family of rodents containing the taxonomic genus Cavia, which includes the domestic guinea pig. The inspected NCBI family tree also contains Dolichotis. Thus Caviidae is broader than either one of those genera, while remaining within Rodentia.^[ref]

For a classification example, a record identified as Cavia porcellus belongs to Cavia and Caviidae. A record assigned to Dolichotis can share the family while belonging to a different genus. The shared family does not make the two records the same species, and a family-level sequence label does not identify the domestic guinea pig specifically.

This matters when comparing biological experiments. A reported response in a named species and preparation cannot be promoted automatically to a measured property of every member of Caviidae. The family supplies evolutionary and taxonomic context, while the experimental organism must still be identified at the resolution needed for the question. The cited classification fixes which provider's family usage is being followed; no numerical species count is needed to understand the distinction.

Dolichotis is a taxonomic genus of rodents in Caviidae. It includes Dolichotis patagonum, the Patagonian mara. The alternative common name Patagonian hare does not place it in Lagomorpha: its family relationship is to rodents such as Cavia.^[ref][ref]

Field observations reveal an unusual combination of social scales. A 1992 study of Dolichotis patagonum described pair relationships together with communal breeding: young from several pairs shared a warren. Larger groups had greater collective vigilance and higher pup survival, although each pair spent less time sitting alert at the warren.^[ref]

An invented time-budget example shows why these measurements differ. Suppose each of two pairs watches during a different ten-minute interval: each pair watches for ten minutes, while the group has twenty minutes with a watcher present. If both watch simultaneously for ten minutes, individual effort is unchanged but collective coverage halves. Real coverage requires recording overlap, not merely adding individual durations. The field association between group size and survival motivates explanations involving predation; it does not by itself isolate a single cause.

Dolichotis patagonum, the Patagonian mara, is a rodent in Dolichotis and Caviidae. Its established wild distribution includes Argentina. Its alternative common name Patagonian hare does not place it in Lagomorpha.^[ref]

The species is useful for studying communal breeding and how observers estimate animal numbers. Young from multiple pairs can share a warren, while adults visit rather than remaining continuously visible there.^[ref] A 2015 study combined an independent search for warrens with video observations of adult attendance. This separated finding gathering places from counting animals associated with them, and examined errors from missed or abandoned warrens and limited observation time.^[ref]

An invented model illustrates the distinction between abundance and detection probability. Suppose ten animals are present and each has probability $p=0.6$ of appearing in a specified observation window. With independent detection, the expected count is $Np=10(0.6)=6$, although abundance is ten. A longer window might raise $p$ without adding animals. Actual mara visits need not be independent; the calculation states a model and explains why raw counts and population change cannot automatically be equated.

Cavia is a taxonomic genus within Caviidae. It includes Cavia porcellus, the domestic guinea pig, and other species such as Cavia aperea. A genus name therefore identifies a broader group than the domestic species alone.^[ref][ref]

An identification example illustrates the information carried by the name. A sample labelled Cavia sp. is assigned to the genus but has not been given a species identification in that label. Replacing it with Cavia porcellus adds a specific claim that requires supporting evidence. Conversely, combining several differently identified Cavia samples under the genus name deliberately discards some taxonomic detail.

The same care applies to experimental results. A measurement made on one guinea pig preparation is evidence about that preparation and its stated biological source. Membership in Cavia helps organize comparisons with related species, but does not establish identical physiology, experimental history or response magnitude. The rank relationship is stable within the cited classification even when individual species treatments or names are revised.

Cavia aperea is a wild species of Cavia, the taxonomic genus that also contains the domestic guinea pig, Cavia porcellus. Both belong to Caviidae. A species name identifies the organism used in an observation; the common name guinea pig alone can obscure the difference between wild and domestic study populations.^[ref][ref]

A 2004 study followed a natural Cavia aperea population in southeastern Brazil for six months. Radio tracking measured space use, direct observations recorded social interactions, and DNA profiling tested genetic relationships. In this low-density population, small groups contained one male and one or two females, occupied comparatively stable home ranges and interacted mainly within their own group. Initial paternity results were consistent with offspring being sired by the group male.^[ref]

The methods answer complementary questions. Overlapping positions can show that two animals use the same area, but do not establish parentage. A genetic parentage result does not describe how often the animals meet. Combining spatial, behavioural and genetic observations therefore tests a social-system interpretation more directly than any one readout. The observed group sizes describe this population and sampling period, rather than imposing one invariant arrangement on every Cavia aperea population.

A rat is a relatively large mouse-like rodent; the common name covers several lineages. In experimental work it often refers to domesticated strains of Rattus norvegicus. Species and strain matter when comparing measured traits.

A native vole affected by habitat change and introduced American mink.

Ondatra zibethicus, a rodent introduced to Britain through fur farming and subsequently eradicated.

Myocastor coypus, a South American rodent whose escaped populations were the subject of an eradication campaign in Britain.

Sciurus vulgaris, whose regional decline or recovery can reflect habitat, competitors, pathogens and predators.

Sciurus carolinensis, native to North America and introduced to Britain and Ireland. Its effects can include competition and pathogen-mediated impacts.

A rodent of the genus Castor, capable of substantial habitat modification. Native regional presence and modern reintroduction require separate evidence.