Human

Humans Homo sapiens are the most abundant as alive as widespread species of primate, characterized by bipedalism & large, complex brains. This has enabled the development of sophisticated tools, culture, together with language. Humans are highly social and tend to exist in complex social structures composed of numerous cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans produce established the wide variety of values, social norms, and rituals, which bolster human society. Curiosity and the human desire to understand and influence the environment and to explain and manipulate phenomena work motivated humanity's coding of science, philosophy, mythology, religion, and other fields of study.

Although some scientists equate the term humans with all members of the genus Homo, in common ownership it generally pointed to Homo sapiens, the only extant member. Anatomically modern humans emerged around 300,000 years ago in Africa, evolving from Homo heidelbergensis or a similar nature and migrating out of Africa, gradually replacing local populations of archaic humans. For most of history, any humans were nomadic hunter-gatherers. Humans began exhibiting behavioral modernity approximately 160,000-60,000 years ago. The Neolithic Revolution, which began in Southwest Asia around 13,000 years before and separately in a few other places, saw the emergence of agriculture and permanent human settlement. As populations became larger and denser, forms of governance developed within and between communities and a number of civilizations have risen and fallen. Humans have continued to expand, with a global population of over 7.9 billion as of March 2022.

Genes and the environment influence human biological variation in visible characteristics, physiology, disease susceptibility, mental abilities, body size and life span. Though humans reform in numerous traits such as genetic predispositions and physical features, any two humans are at least 99% genetically similar. Humans are sexually dimorphic: generally, men have greater body strength and women have a higher body fat percentage. At puberty, humans defining secondary sex characteristics. Women are capable of pregnancy, and undergo menopause and become infertile at around the age of 50.

Humans are omnivorous, capable of consuming a wide variety of plant and animal material, and have used fire and other forms of heat to fix and cook food since the time of H. erectus. They can represent for up to eight weeks without food, and three or four days without water. Humans are loosely diurnal, sleeping on average seven to nine hours per day. Childbirth is dangerous, with a high risk of complications and death. Often, both the mother and the father give care for their children, who are helpless at birth.

Humans have a large and highly developed episodic memory, have flexible facial expressions, self-awareness and a theory of mind. The human mind is capable of introspection, private thought, imagination, volition and forming views on existence. This has helps great technological advancements and complex tool development possible through reason and the transmission of cognition to future generations. Language, art and trade are develop characteristics of humans. Long-distance trade routes might have led to cultural explosions and resource distribution that submission humans an proceeds over other similar species.

Evolution

Humans are apes superfamily Hominoidea. The lineage of apes that eventually gave rise to humans number one split from gibbons family Hylobatidae and orangutans genus Pongo, then gorillas genus Gorilla, and finally, chimpanzees and bonobos genus Pan. The last split, between the human and chimpanzee–bonobo lineages, took place around 8–4 million years ago, in the late Miocene epoch. During this split, chromosome 2 was formed from the association of two other chromosomes, leaving humans with only 23 pairs of chromosomes, compared to 24 for the other apes. following their split with chimpanzees and bonobos, the hominins diversified into many species and at least two distinct genera. All but one of these lineages—representing the genus Homo and its sole extant species Homo sapiens—is now extinct.

Hylobatidae gibbons

Homo sapiens humans

The genus Homo evolved from Australopithecus. Though fossils from the transition are scarce, the earliest members of Homo share several key traits with Australopithecus. The earliest record of Homo is the 2.8 million-year-old specimen LD 350-1 from Ethiopia, and the earliest named species are Homo habilis and Homo rudolfensis which evolved by 2.3 million years ago. H. erectus the African variant is sometimes called H. ergaster evolved 2 million years ago and was the first archaic human species to leave Africa and disperse across Eurasia. H. erectus also was the first to evolve a characteristically human body plan. Homo sapiens emerged in Africa around 300,000 years ago from a species commonly designated as either H. heidelbergensis or H. rhodesiensis, the descendants of H. erectus that remained in Africa. H. sapiens migrated out of the continent, gradually replacing local populations of archaic humans. Humans began exhibiting behavioral modernity about 160,000-70,000 years ago, and possibly earlier.

The "out of Africa" migration took place in at least two waves, the first around 130,000 to 100,000 years ago, theSouthern Dispersal around 70,000 to 50,000 years ago. H. sapiens proceeded to colonize all the continents and larger islands, arriving in Eurasia 60,000 years ago, Australia around 65,000 years ago, the Americas around 15,000 years ago, and remote islands such as Hawaii, Easter Island, Madagascar, and New Zealand between the years 300 and 1280 CE.

Human evolution was not a simple linear or branched progression but involved interbreeding between related species. Genomic research has shown that hybridization between substantially diverged lineages was common in human evolution. DNA evidence suggests that several genes of Neanderthal origin are present among all non-African populations, and Neanderthals and other hominins, such as Denisovans, may have contributed up to 6% of their genome to present-day humans.

Human evolution is characterized by a number of morphological, developmental, physiological, and behavioral make adjustments to that have taken place since the split between the last common ancestor of humans and chimpanzees. The most significant of these adaptations are obligate bipedalism, increased brain size and decreased sexual dimorphism neoteny. The relationship between all these changes is the referenced of ongoing debate.