Encyclopedia of Evolution.pdf - Online Reading Center

Homo antecessor
Hominin evolution occurred in numerous lineages, with
(except for the last 20,000 years) more than one lineage existing
at the same time and often in the same general location. In
general, hominin evolution involved bipedalism, the increase
in brain size, the reduction in tooth size, and the invention
of technology. Art and religion (see religion, evolution
of) are now and may always have been unique to H. sapiens,
which is the only surviving hominin species.
Further Reading
Behrensmeyer, Anna K. “Climate change and human evolution.” Science
311 (2006): 476–478.
Calvin, William H. A Brain for All Seasons: Human Evolution and
Abrupt Climate Change. Chicago: University of Chicago Press,
2002.
Chimpanzee Sequencing and Analysis Consortium. “Initial sequence
of the chimpanzee genome and comparison with the human
genome.” Nature 437 (2005): 69–87.
Gibbons, Ann. The First Humans: The Race to Discover Our Earliest
Ancestors. New York: Doubleday, 2006.
Hart, Donna L., and Robert W. Sussman. Man the Hunted: Primates,
Predators, and Human Evolution. New York: Westview, 2005.
Hillier, LaDeana W., et al. “Generation and annotation of the DNA
sequences of human chromosomes 2 and 4.” Nature 434 (2005):
724–731.
Johanson, Donald, Lenora Johanson, and Blake Edgar. Ancestors: In
Search of Human Origins. New York: Villard, 1994.
Khaitovich, Phillip, et al. “Parallel patterns of evolution in the
genomes and transcriptomes of humans and chimpanzees.” Science
309 (2005): 1,850–1,854.
Leakey, Richard, and Roger Lewin. Origins Reconsidered: In Search
of What Makes Us Human. New York: Doubleday, 1992.
Sawyer, G. J., et al. The Last Humans: A Guide to Twenty Species of
Extinct Humans. New Haven, Conn.: Yale University Press, 2006.
Stringer, Chris, and Peter Andrews. The Complete World of Human
Evolution. London: Thames and Hudson, 2005.
Tattersall, Ian, and Jeffrey Schwartz. Extinct Humans. New York:
Westview, 2000.
Templeton, Alan R. “Out of Africa again and again.” Nature 416
(2002): 45–51.
Walker, Alan, and Pat Shipman. The Wisdom of the Bones: In Search
of Human Origins. New York: Knopf, 1996.
Winckler, Wendy, et al. “Comparison of fine-scale recombination
rates in humans and chimpanzees.” Science 308 (2005): 107–111.
Summary by Jorde, Lynn B., Science 308 (2005): 60–62.
Homo antecessor See Homo HeiDelbergensis.
Homo erectus In the broad sense, Homo erectus refers to
the human species intermediate between Homo Habilis and
modern humans. Most modern anthropologists divide these
humans into at least three species: Homo ergaster, the
African “erectus” species that evolved from H. habilis and
was the ancestor of the other “erectus” species, as well as of
modern humans (see Homo sapiens); Homo HeiDelbergensis,
the “erectus” humans that migrated to Europe and
evolved into Neandertals; and the Asian “erectus” humans,
including Java man and Peking man, which retain the original
name H. erectus.
Not long after H. ergaster evolved in Africa, some of
its populations began to migrate northward and eastward.
Before a million years ago, H. erectus individuals were probably
living in caves in what is now China, as well as on islands
in what is now Indonesia. Specimens from the Chinese populations
(Peking man) are known from 670,000 to 410,000
years ago. Specimens from the Indonesian populations (Java
man) that are 1.8 million years old are known, and Java man
may have persisted until as recently as 50,000 years ago. On
Flores Island, a population of H. erectus apparently evolved
into a species of miniature humans, H. floresiensis, who survived
until perhaps 18,000 years ago (see Flores Island
people). None of these populations, Peking man, Java man,
or the Flores Island people, evolved into modern humans.
Java man was the first human fossil to be found outside
of Europe, and the first fossil that could clearly be
interpreted as being more primitive than modern humans. A
Dutch physician (see Dubois, Eugène) found a skullcap in
Trinil, Indonesia, in 1891, and a thighbone in 1892. Dubois
at first called this species Anthropopithecus, the man-ape,
then changed it to Pithecanthropus erectus, using the name
of a hypothetical human ancestor that had been proposed
by a leading German evolutionary scientist (see Haeckel,
Ernst). In the early 20th century, anthropologist Davidson
Black excavated fossils from Dragon Bone Hill in China.
For many years, local people had gathered the bones (which
they called dragon bones) and ground them as medicine.
Black found enough bones to reconstruct a species intermediate
between apes and humans, which he called Peking
man (Sinanthropus pekinensis). When World War II started,
Europeans evacuated from China ahead of Japanese troops.
American Marines were taking the Peking man bones when
they were arrested by Japanese soldiers, who may have discarded
the bones. Black and anthropologist Franz Weidenreich
had made casts of the bones, which have survived.
Early in the 20th century, anthropologist Ralph von Koenigswald
found bones of Solo man, near the Solo River in
Indonesia. He offered 10 cents per bone fragment to local
excavators to bring him specimens, only to find that the
excavators shattered the bones that they found in order to
get more money. Java, Peking, and Solo man are now all
considered to be populations of H. erectus.
H. erectus evolved some unique skull characteristics that
allow it to be classified as a distinct species. First, some populations
of H. erectus may have evolved a larger brain size,
independently of the lineages that led to Neandertals and to
modern humans. However, too few reliable estimates of brain
size are available to determine whether this was a general
trend. Second, H. erectus had thick skulls. Anthropologists
Noel Boaz and Russell Ciochon point out that the particular
pattern of thickness appears to be just right for protecting the
brain from blows delivered to the top of the head. H. erectus
individuals apparently hit each other with clubs often enough
and for a long enough time that it influenced the evolution of
their skulls.