Earliest Homo sapiens appeared approximately 700,000 years ago, although anatomically modern humans are known from about 100,000 years ago. Patterns of colonization of the world by ancient humans and the details of interactions between ancient Homo sapiens and co-occurring Homo species are areas of active research.
Like most primates, humans use vision extensively in perception and communication. Humans have excellent color vision, although visual acuity in low light is limited. Humans also use sounds extensively. Human languages represent one of the most complex systems of communication in the animal world, and the diversity of human languages is astounding. Touch is an important mode of perception, it is especially important in close social bonds. Humans have a moderately well developed sense of smell and taste, which is used to determine the suitability of foods and discover information about the environment and conspecifics.
The evolution of complex language is considered one of the hallmarks of Homo sapiens. Archaic humans were capable of complex language, although Homo sapiens anatomy seems to have evolved to favor the production of complex sounds in anatomically modern humans.
Communication Channels: visual ; tactile ; acoustic ; chemical
Other Communication Modes: pheromones
Perception Channels: visual ; tactile ; acoustic ; chemical
Human populations are not monitored by conservation agencies. Although human populations worldwide are large and growing, some regional or isolated populations may be in decline as a result of economic disadvantage, disease, habitat degradation, emigration, and cultural erosion.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Human interactions are often complex and negative at interpersonal levels and among social groups, cultures, and governments. Human activities often destroy or transform ecosystems, and these changes can have negative economic and/or medical impacts on other human populations.
Humans act as top predators in many ecosystems, although they are also sometimes preyed on by larger predators, such as tigers. Humans modify habitats and ecological communities in countless ways, often substantially changing the interactions of nearly all other species in those habitats.
Humans are parasitized by many species of internal and external parasites. Some research suggests that hairlessness in humans is an adaptation to reduce ectoparasite loads.
Humans and human societies have evolved multiple relationships with other species, including commensal species and domesticated and companion species. Human commensals are too numerous to mention, but some important commensal species are house mice (Mus musculus), black rats (Rattus rattus), Norway rats (Rattus norvegicus), and Oriental cockroaches (Periplaneta americana). Important domestic species include domestic dogs (Canis lupus familiaris), pigs (Sus scrofa), cattle (Bos taurus), sheep (Ovis aries), goats (Capra hircus), chickens (Gallus gallus), guinea pigs (Cavia porcellus), horses (Equus caballus), llamas (Lama glama), camels (Camelus species), turkeys (Meleagris gallopavo), honeybees (Apis mellifera), and many other animals. Humans have also domesticated many species of plants for food and other uses, such as corn (Zea mays), rice (Oryza sativa), wheat (Triticum aestivum), manioc (Manihot esculenta), apples (Malus domestica), and soy (Glycine max).
Ecosystem Impact: creates habitat
Mutualist Species:
Commensal/Parasitic Species:
Humans generally eat a highly variable omnivorous diet. The components of diets vary tremendously with regional availability of foods. Some human cultures restrict their diet to a vegetarian one, relying on plant sources of proteins. Foods are often extensively prepared and stored for future use. The use of fungal colonies, such as yeasts, for creating cultured foods, such as beer, bread, and cheeses, is widespread.
Animal Foods: birds; mammals; amphibians; reptiles; fish; eggs; blood; body fluids; carrion ; insects; terrestrial non-insect arthropods; mollusks; terrestrial worms; aquatic crustaceans; echinoderms; other marine invertebrates
Plant Foods: leaves; roots and tubers; wood, bark, or stems; seeds, grains, and nuts; fruit; nectar; pollen; flowers; sap or other plant fluids; algae; macroalgae
Other Foods: fungus; microbes
Foraging Behavior: stores or caches food
Primary Diet: omnivore
Humans are currently found throughout the world; in permanent settlements on all continents except Antarctica and on most habitable islands in all of the oceans. All available evidence suggests that humans originated in Africa.
Anatomically modern Homo sapiens populations are known from the Middle East as long as 100,000 years ago, from east Asia as long as 67,000 years ago, and southern Australia as long as 60,000 years ago. European Homo sapiens fossils are known from 35,000 years ago. Homo sapiens populations were once thought to have colonized the New World approximately 11 to 13,000 years ago, but recent research indicates earlier dates of colonization. This is an area of active research.
Biogeographic Regions: nearctic (Native ); palearctic (Native ); oriental (Native ); ethiopian (Native ); neotropical (Native ); australian (Native ); oceanic islands (Native )
Other Geographic Terms: cosmopolitan
Humans are found in all terrestrial habitats worldwide. Humans extensively modify habitats as well, creating areas that are habitable by a much reduced set of other organisms, as in urban and agricultural areas. With the aid of technologies such as boats, humans also venture into many aquatic habitats, primarily to obtain food.
Habitat Regions: temperate ; tropical ; polar ; terrestrial
Terrestrial Biomes: tundra ; taiga ; desert or dune ; savanna or grassland ; chaparral ; forest ; rainforest ; scrub forest ; mountains
Wetlands: marsh ; swamp
Other Habitat Features: urban ; suburban ; agricultural ; riparian ; estuarine ; intertidal or littoral ; caves
Human lifespans vary tremendously with nutritional status and exposure to diseases and trauma. Humans can live more than 100 years; the longest lived human that has been documented was 122 years old. Most humans live 50 to 80 years old, providing they survive their most vulnerable childhood years. Average life expectancy in many parts of the developing world is from less than 40 years old to 65 years old. In the developed world average life expectancy can be over 80 years old.
Typical lifespan
Status: wild: 32 to 84 years.
Humans are an exceptionally diverse species morphologically and many aspects of size vary substantially with environmental factors such as nutritional status. Historically there has been an effort to organize human physical variation into "races," although there is no scientific basis for the application of a race concept to human variation. Human physical variation is continuous and available evidence suggests that gene flow among human populations throughout their history has been the rule rather than the exception.
Humans are characterized by their bipedalism and their lack of significant body hair. Males are generally larger than females, with more pronounced muscle development and generally more hair on the face and torso than females.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry ; polymorphic
Sexual Dimorphism: male larger; sexes shaped differently
Humans have few natural predators and often sit at or near the top of the food chain in regional ecosystems. Humans are sometimes opportunistically preyed on by large wild cats, such as tigers (Panthera tigris) and lions (Panthera leo). Other instances of large, carnivorous animals eating humans are often cases of mistaken identity or are opportunistic events. This includes cases involving large sharks, bears, monitor lizards, and crocodiles.
Known Predators:
Human cultures are marked by a wide range of approaches to mating. Child-rearing in most cultures is accomplished with some degree of help and cooperation from other members of the group, including related and unrelated members.
Mating System: monogamous ; polyandrous ; polygynous ; polygynandrous (promiscuous) ; cooperative breeder
Humans are capable of breeding throughout the year. Gestation length is 40 weeks on average, a fairly long gestation length for a primate species with altricial young. Typically one young is born, although twins occur occasionally and multiple births rarely. Interbirth intervals, birth weights, time to weaning, independence, and sexual maturity all vary substantially with nutritional status of mothers and young and are influenced by cultural practices.
Breeding interval: Human females can reproduce up to once every 10 months, although typical birth intervals are longer and vary substantially.
Breeding season: Humans can breed at any time of the year.
Range number of offspring: 1 (low) .
Average gestation period: 40 weeks.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Human infants are born in an altricial state and require intense and long-term care to ensure survival. Parental care is variable across human cultures, but generally the mother plays a large role in caring for infants through weaning. Family members and unrelated community members also often play large roles in caring for young. Human young experience an extended period of adolescence in which many essential skills and cultural knowledge are learned and practiced. Human social structures are complex and frequently young remain part of the same larger social groups as their parents and their paternal and maternal families. Social stature of parents often also plays a large role in the social stature of the young.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female); post-independence association with parents; extended period of juvenile learning; inherits maternal/paternal territory; maternal position in the dominance hierarchy affects status of young
