Evolution Of Humans

Human evolution is the biological and cultural development of humans. A human is
any member of the species Homo sapiens, meaning "wise man." Since at least
the Upper Paleolithic era, some 40,000 years ago, every human society has
devised a creation myth to explain how humans came to be. Creation myths are
based on cultural beliefs that have been adopted as a legitimate explanation by
a society as to where we came from. The science of paleoanthropology, which also
tries to create a narrative about how humans came to be, is deeply technical.

Paleoantropology is the science of the evolution of humans, and it is the base
of all research in that field. Humans have undergone many different changes
during the last hundred million years, and it is the paleoanthropologist’s job
to identify and explain these changes. In this research paper I will examine:
human physical traits that define their species, human origins from pre-humans
to modern humans, major discoveries and the history of human evolution, and what
the future may hold as far as evolution for the human species. Homo sapiens are
the only living representative of the family Hominidae. The Hominidae, or
hominids are a group of upright walking primates with relatively large brains.

So all humans are hominids, but not all hominids could be called human. Next all
humans are primates. The mammalian order of primates include about 180 species
of prosimians (lemur like animals), monkeys, apes, and ourselves. Primates are
unusual mammals for they have evolved such distinctive traits as highly
developed binocular vision, mobile fingers and toes with flat nails instead of
claws, a shortened snout with a reduced sense of smell, and large brains
relative to body size. If primates are unusual for mammals, humans are even more
unusual for primates. We are essentially elaborated African apes. We share
almost 99 percent of our genetic material with chimpanzees. Yet we have several
traits that are very different. Two legged walking, or bipedalism seems to be
one of the earliest of the major hominine characteristics to have evolved. To
accommodate this strange position, we have developed a specialized pelvis, hip
and leg muscles, and an S-shaped vertebral column. Because these changes can be
documented in fossil bone, bipedalism is seen as the defining trait of the sub
family Homininae. Much of the human ability to make and use tools and other
objects stem from the large size and complexity of the human brain. Most modern
humans have a braincase volume of between 79.3 and 91.5 cubic inches. In the
course of human evolution the size of the brain has more than tripled. The
increase in brain size may be related to changes in hominine behavior. Over time
stone tools, and other artifacts became increasingly numerous and sophisticated.

It is likely that the increase in human brain size took place as part of a
complex interrelationship that included the elaboration of tool use and tool
making, as well as other learned skills which permitted our ancestors to be
increasingly able to live in a variety of environments. The earliest hominine
fossils show evidence of marked differences in body size, which may reflect a
pattern of the different sexes in our early ancestors. The bones suggest that
females may have been 3 to 4 ft in height and about 60 to 70 lb. in weight,
while males may have been somewhat more than about 5 ft tall, weighing about 150
lb. The reasons for this body size difference are disputed, but may be related
to specialized patterns of behavior in early hominine social groups. This
extreme difference between sexes appears to disappear gradually sometime after a
million years ago. The third major trend in hominine development is the gradual
decrease in the size of the face and teeth. All the great apes are equipped with
large, tusklike canine teeth that project well beyond the level of the other
teeth. The earliest hominine remains possess canines that project slightly, but
those of all later hominines show a marked reduction in size. Also, the chewing
teeth, the premolars and molars, have decreased in size over time. Associated
with these changes is a gradual reduction in the size of the face and jaws. In
early hominines, the face was large and positioned in front of the braincase. As
the teeth became smaller and the brain expanded, the face became smaller and its
position changed. Thus, the relatively small face of modern humans is located
below, rather than in front of, the large, expanded braincase. Evidence of
immediate relatives of the human species begins about five million years ago
with the