- published: 24 Jul 2016
- views: 162050
Animals are multicellular, eukaryotic organisms of the kingdom Animalia (also called Metazoa). All animals are motile, meaning they can move spontaneously and independently, at some point in their lives. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their lives. All animals are heterotrophs: they must ingest other organisms or their products for sustenance.
Most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago. Animals are divided into various sub-groups, some of which are: vertebrates (birds, mammals, amphibians, reptiles, fish); molluscs (clams, oysters, octopuses, squid, snails); arthropods (millipedes, centipedes, insects, spiders, scorpions, crabs, lobsters, shrimp); annelids (earthworms, leeches); sponges; and jellyfish.
The word "animal" comes from the Latin animalis, meaning having breath, having soul or living being. In everyday non-scientific usage the word excludes humans – that is, "animal" is often used to refer only to non-human members of the kingdom Animalia; often, only closer relatives of humans such as mammals, or mammals and other vertebrates, are meant. The biological definition of the word refers to all members of the kingdom Animalia, encompassing creatures as diverse as sponges, jellyfish, insects, and humans.
Found may refer to:
Living may refer to:
Inside may refer to:
Modern humans (Homo sapiens, primarily ssp. Homo sapiens sapiens) are the only extant members of Hominina clade (or human clade), a branch of the taxonomical tribe Hominini belonging to the family of great apes. They are characterized by erect posture and bipedal locomotion, manual dexterity and increased tool use, and a general trend toward larger, more complex brains and societies.
Early hominins—particularly the australopithecines, whose brains and anatomy are in many ways more similar to ancestral non-human apes—are less often referred to as "human" than hominins of the genus Homo. Some of the latter used fire, occupied much of Eurasia, and gave rise to anatomically modern Homo sapiens in Africa about 200,000 years ago. They began to exhibit evidence of behavioral modernity around 50,000 years ago, and migrated in successive waves to occupy all but the smallest, driest, and coldest lands.
The spread of humans and their large and increasing population has had a profound impact on large areas of the environment and millions of native species worldwide. Advantages that explain this evolutionary success include a relatively larger brain with a particularly well-developed neocortex, prefrontal cortex and temporal lobes, which enable high levels of abstract reasoning, language, problem solving, sociality, and culture through social learning. Humans use tools to a much higher degree than any other animal, are the only extant species known to build fires and cook their food, and are the only extant species to clothe themselves and create and use numerous other technologies and arts.