1. During the 18th century, many scholars became interested in biological diversity, human origins, and the human position within the classification of plants and animals (e.g., the first comprehensive and still influential taxonomy of plants and animals by Carolus Linnaeus)

2. The commonly accepted explanation for the origin of species during the 18th century was creationism, which accounts for biological diversity by referring to the divine act of Creation as described in Genesis.

3. The discovery of fossil remains of creatures clearly unknown to modern humans was not accountable within the basic terms of creationism.

4. Catastrophism arose as a modified version of creationism, positing divinely authored worldwide disasters that wiped out ancient species; presented new, divine events of species creation; and permitted the survival of some ancient species in isolated areas to explain the existence of fossil remains.

5. According to both theories of creationism, biological similarities and differences originated in events of Creation and had not changed.

6. The alternative to creationism and catastrophism was transformism, also called evolution.

7. Charles Darwin was influenced by Sir Charles Lyell's principle of uniformitarianism.

8. Darwin applied the theory of the long-term transformation through natural forces to living things, and, when integrated into evolutionary theory, uniformitarianism cast doubt on whether the world was only 6,000 years old, as posited in creationism.

9. Like other evolutionists, Darwin argued for the primordial relatedness of all life forms.

1. The fact of evolution was known prior to Charles Darwin's influential research and writing (e.g., by Darwin's grandfather Erasmus Darwin who proclaimed in 1794 the common ancestry of all animal species in Zoomania), but Charles Darwin importantly contributed a theory of evolution through natural selection (explaining how evolution occurred).

2. Darwin posited natural selection as the single theory that could explain the origin of species, biological diversity, and similarities among related life forms (reaching this conclusion along with Alfred Russell Wallace).

3. Natural selection is the gradual process by which the forms most fit to survive and reproduce in a given environment do so in greater numbers than others in the same population.

4. For natural selection to work on a given population, there must be variety within that population (as there always is) and competition for strategic resources.

5. The concept of natural selection argues that organisms which have a better fit within their environmental niche will reproduce more frequently than those organisms that fit less well.

6. Through a gradual, branching process, involving adaptation to thousands of environments, natural selection has produced the diverse plants and animals found in the world today.

1. Taxonomy: the assignment of organisms to categories.

2. Hominoidea (hominoids): the superfamily containing humans and apes.

3. Phylogeny: genetic relatedness based on common ancestry.

1. Organisms are placed in classifications, which are arranged hierarchically according to degree of genetic relatedness.

2. Phylogenetic classification is a descending hierarchy of classifications, from most inclusive to least inclusive.

3. A species is a group of organisms whose mating produces viable and fertile offspring.

1. Similarities that organisms share because of common ancestry are called homologies.

2. The presence of homologies is the principal factor in determining how organisms are assigned to taxonomic categories.

1. Hominidae is the name of the zoological family that includes hominids, fossil and living humans.

2. Many scientists now also place chimps and gorillas in the hominid family.

3. To specify the group that leads to humans but not to chimps and gorillas, the tribe hominini refers to all the human species that ever have existed (including the extinct ones) and excludes chimps and gorillas.

1. Grasping (precision grip, thumb opposability, nails instead of claws).

2. Smell to Sight (stereoscopic vision, eye placement, brain organization, and color vision all reflect a general primate emphasis upon sight over smell).

3. Nose to Hand (increasing reliance on sense of touch, specifically in the sensitive pads of the fingers, as opposed to the muzzle or whiskers, for information).

4. Brain Complexity (the brain areas devoted to thought, memory, and association are more elaborate and proportionally larger in primates than in most mammals).

5. Parental Investment (single offspring births combined with longer development periods provide more opportunities for learning in primates than in most other mammals).

6. Sociality (strongly associated with parental investment, cooperative social groups are selected for in part because of the needs arising from primate parenting).

1. The so-called great apes are orangutans, gorillas, and chimpanzees.

2. Ape behavior and anatomy reveal past and present adaptation to arboreal life.

3. The terrestrial locomotion of chimps and gorillas is called knuckle-walking.

1. Neotony and life in cooperative social groups allow primates to learn behavior from other primates and modify social patterns, rather than relying only on genetically encoded behaviors.

2. Learned behavior has been observed in monkeys as well as apes.

1. Tool use allows primates to adapt to a wide range of ecological niches more quickly than through physiological adaptation alone (although primates are not the only animals that use tools).

2. Modern humans employ tools more often than any other animal.

3. Wild chimpanzees have been observed making tools to probe termite hills and constructing leaf "sponges" for collecting water, for example.

1. Hunting is a regular component of wild chimpanzee behavior.

2. Hunting by chimps is both opportunistic and planned.

3. Wild chimpanzees have been observed hunting consistently, using cooperative techniques, with some sex specialization (males hunt more than females).

1. Sharing and cooperation are common to most primates; however, humans share and cooperate in more complex ways.

2. Except for meat sharing by chimps, the ape tendency is to forage individually.

3. Through millions of years of adaptation to an omnivorous diet, humans have come to rely, more than any other primate, on hunting, food sharing, and cooperative behavior.

1. Unlike baboons, chimpanzees, and other primates, human females do not experience estrus, a period of maximum sexual receptivity signaled by vaginal area swelling and coloration.

2. Humans maximize their reproductive success by engaging in year-round mating.

3. Marriage and kinship are two exclusively human systems that universally give identity, alliances, and stability to certain types of human relationships in a way that is absent among other primate social systems.

1. The most widely accepted theories of bipedalism stress the advantages it provided in a habitat increasingly dominated by dry, savanna-like conditions.

2. Bipedalism provides the ability to see over long grass for food and predators and to carry items back to a home base.

3. Bipedalism is more energy efficient and therefore advantageous in a grassland, where resources are more dispersed than in forests.

4. Bipedalism exposes less body surface area to solar radiation, which facilitates cooling and reduces moisture loss.

1. Compared with contemporary humans, early hominins had very small brains. Brain size has increased during hominin evolution, especially with the advent of the genus Homo.

2. Compared with the young of other primates, human children have a long period of childhood dependency, during which their brains and skulls grow dramatically.

1. Early hominins likely shared the ability to use and manufacture tools as a homology with the apes.

2. Upright bipedalism would have permitted the use and carriage of tools and weapons against predators in an open grassland habitat.

1. As they adapted to a savannah diet of fibrous, gritty vegetation, it was advantageous for early hominins to have large back teeth and thick tooth enamel.

2. The rotary motion associated with chewing this vegetation also favored reduction of the canines and first premolars (bicuspids).

1. A. anamensis (4.2 to 3.9 m.y.a.).

2. A. afarensis (3.8? to 3.0 m.y.a.).

3. A. africanus (3.0? to 2.0? m.y.a.).

4. A. garhi (2.5 m.y.a.)

5. A. robustus (2.0? to 1.0? m.y.a.).

6. A. boisei (2.6? to 1.0 m.y.a.).

1. A. anamensis is a bipedal hominin from northern Kenya, whose fossil remains were first discovered by Maeve Leakey and Alan Walker in 1995.

2. Fossils from two sites date to 4.2 m.y.a. (Kanapoi) and to 3.9 m.y.a. (Allia Bay).

3. A. anamensis may be ancestral to A. afarensis, which is usually considered ancestral to all the later australopithecines as well as to Homo.

1. Earliest definite A. afarensis remains are dated at 3.8 m.y.a. and (with Ardipithecus and A. anamensis) strongly support a very recent (8 m.y.a. at the most) divergence from common ancestry with apes, because of the clearly apelike features found in all three species.

2. Like apes, and unlike modern humans, A. afarensis had sharp canine teeth that projected beyond the other teeth, and the lower premolar was pointed and projecting to sharpen the upper canine. Fossils of molars and jaws indicate the beginnings of adaptation to a coarse (seeds, lots of sand) savanna diet.

3. Cranial remains show that afarensis was still remarkably "apelike" is some respects. The brain capacity was only slightly larger than a modern chimpanzee's, and the jaw and overall body size indicate considerable sexual dimorphism.

4. Postcranial remains, particularly the pelvis, leg, feet, and spinal entry into the skull, all indicate bipedalism, and are thus clearly hominin.

5. A. anamensis (4.2 - 3.9 m.y.a.) and Ardipthecus (5.8 - 4.4 m.y.a.) remains also indicate bipedalism, and thus bipedalism predates A. afarensis.

6. A. afarensis young probably depended on their parents for a relatively long time, facilitating social learning.

1. The relationship between the graciles (A. africanus) and the robusts (A. robustus) has been debated for generations but not resolved.

2. A similar debate obtains for A. robustus vs. A. boisei, but it is most likely that boisei developed from robustus into a separate, hyperrobust species, highly specialized (giant molars, sagittal crest, relatively small front teeth) for a savanna vegetation diet.

3. Brain size increased only slightly between A. afarensis (430 cm³), A. africanus (490 cm³), and A. robustus (540 cm³). These figures can be compared with an average cranial capacity of 1,350 cm³ in Homo sapiens.

4. The skulls, jaws and teeth of the australopithecines indicate their diet was mainly vegetarian, requiring extensive crushing and grinding.

1. Contemporaneous (2 m.y.a.) sets of teeth, very different in size, constitute the earliest evidence of a split between the ancestors of Homo (H. habilis) and the later australopithecines, such as A. boisei.

2. The distinctive early Homo trends are a rapid increase in brain size, increasingly elaborate toolmaking, and an increasing emphasis on hunting and gathering, but there remains considerable debate as to when and in what population these trends led to speciation (from an australopithecine to Homo habilis).

3. H. habilis lived between 2 m.y.a. and about 1.7 m.y.a., by which time it had evolved into H. erectus.

4. Fossil evidence suggests an acceleration in hominin evolution during the 100,000-200,000-year period between late H. habilis (1.8 m.y.a.) and early H. erectus (1.7-1.6 m.y.a.).

1. The oldest known manufactured tools, dated at 2.5-2 m.y.a., were found in Ethiopia, Congo, and Malawi and are grouped under the name Oldowan pebble tools, given to them by L.S.B. and Mary Leakey in 1931.

2. Core tools and choppers are the most common stone tools found at early African tool sites, and these may have been used for food processing, particularly to dismember game carcasses and break open marrow cavities.

3. Tool making became more sophisticated soon after the advent of H. erectus in Africa, with tools dating to 1.8 m.y.a. showing differences in form that possibly correspond with functional differentiation.

1. The stone tool-making techniques that evolved out of the Oldowan tradition and that lasted until about 15,000 years ago are described by the term Paleolithic.

2. The three Paleolithic divisions are roughly associated with a particular stage in human evolution.

1. Culture/Biology Synergy

2. Hunting and Gathering

1. The Pleistocene (2 m.y.a. to 10,000 B.P.) is the epoch of human life.

2. During the Pleistocene there were several ice ages, or glacials.

1. Spanish researchers at the site of Gran Dolina have found the remains of 780,000-year-old hominins that they call H. antecessor and see as a possible common ancestor of the Neandertals and anatomically modern humans.

2. A massive hominin jaw (dated to around 500,000 years old), discovered in 1907 near Heidelberg, Germany, was initially termed H. heidelbergensis, a species name that has recently been revived to refer to a group of fossil hominins otherwise described as either late H. erectus or archaic H. sapiens (dated between 700,000 and 200,000 years ago and found in various parts of the world, including Asia, Europe, and Africa).

3. There is archaeological evidence for the presence and behavior of late H. erectus and then archaic H. sapiens in Europe.

1. The combination of a relatively large torso and short limbs, along with large, broad nasal passages, is evidence of adaptation to a cold climate.

2. Neandertal front teeth were extremely large and the remains of these show evidence of wear, suggesting they were used for varied purposes.

3. The face, particularly the large browridge, was designed to support considerable stress on the front teeth (possibly the result of chewing animal hides).

1. Scientists continue to debate Neandertals' place in the ancestry of anatomically modern humans (AMHs). However, the current prevailing view posits that Neandertals were the product of a split within the H. erectus population, wherein one side moved into northern Europe and became Neandertals, and the other side evolved into AMHs in the Middle East, Africa, or Asia and then drove Neandertals to extinction upon moving into their territories.

2. Scientists who maintain the view that Neandertals could have contributed to the ancestry of AMHs in Europe cite certain fossils (e.g., from the Central European site of Mladec, l'Hortus in France, and Vindija in Croatia) that combine Neandertal robustness with modern features to support their position.

3. Fossils from Israel's Mount Carmel site of Skhul and the Israeli site of Qafzeh combine archaic and modern features, but most analyses stress the "modernness" of these fossils, dating to 100,000 B.P and 92,000 B.P. respectively, and thus question the Neandertal ancestry of AMHs in Europe and the Middle East.

1. Only the mother contributes mtDNA to an offspring, and this occurs through cloning, thus only mutation may change the pattern of mtDNA from one generation to the next.

2. Researchers from the University of California at Berkeley generated a computerized model of Homo evolution, based upon the average rate of mutation in 147 known samples of mtDNA.

3. The model drew an evolutionary tree, at the base of which is a single female (dubbed "Eve") who lived in sub-Saharan Africa around 200,000 years ago, from whom all modern humans have descended.

4. The details of the Eve theory suggest that her descendants left Africa no more than 135,000 years ago, eventually replacing the Neandertals in Europe and colonizing the rest of the world.

1. Fossil and archaeological evidence has been accumulated to support the African origin of AMHs perhaps by 150,000 years ago.

2. A 1997 discovery in an Ethiopian valley of three anatomically modern skulls (dated to 154,000 to 160,000 B.P.) provides support for the view that modern humans originated in Africa and then spread into Europe and Asia. The skulls are "anatomically modern" - long with broad midfaces, featuring tall, narrow nasal bones.

1. Toolmaking technology shifted from flaking (Middle Paleolithic Mousterian) to the making of Upper Paleolithic blade tools, which is much more efficient and allows for greater specialization and diversity.

2. Tool Diversity

1. Between 7 and 5 million years ago, our hominin ancestors originated in Africa, as apelike creatures became bipeds.

2. By 2.5 million years ago, hominins were making crude stone tools.

3. By 1.7 million years ago, hominins had spread from Africa into Asia and eventually into Europe.

1. The traditional view has been that modern behavior originated around 40,000 years ago, only after H. sapiens had pushed into Europe.

2. One of the key topics of investigation is trying to explain the long time lag between the time when the species first looked modern (150,000-100,000 B.P.) and the time when it started acting modern (90,000-40,000 B.P.)

1. Klein argues that around 50,000 B.P. a genetic mutation rewired the human brain, allowing for an advance in language.

2. This improved communication gave humans the capacity for behavioral modernity.

3. The fossil record does not support this model; AMH skulls from this time period show no change in brain size or function.

1. The last 30 years have witnessed the discovery of evidence for early modern behavior in Africa and the Middle East prior to 40,000 B.P. in the form of finely made stone and bone tools, long-distance exchange, dietary changes, self-ornamentation, and abstract carvings.

2. Evidence from sites in Africa dating from 300,000 to 30,000 B.P. suggests a long process of gradual cultural development followed by a migration out of Africa with a fairly developed culture.

3. What might appear to be a sudden cultural revolution outside of Africa around 40,000 B.P. (Klein) was the product of gradual evolution in Africa.

1. Klein argues that behavioral modernity was the result of a genetic change that rewired the brain around 50,000 B.P.

2. Other researchers argue the capacity for behavioral modernity was present in AMHs long before it was expressed.

3. Behavioral modernity arose due to an increase in the frequency and duration of interactions between AMH communities.

1. Kelsey Foster worked to determine the butchering pattern used by Paleolithic hunters at the Verberie le Buisson Campin site, located along the banks of the Oise River in northern France.

2. Foster examined the faunal remains from the entire upper occupation level of the site - 1,133 specimens of reindeer bone fragments - for any indication of human modification of bone.

3. Foster found that Paleolithic occupants at Verberie systematically processed bone marrow, involving a butchering sequence of primary dismemberment of the carcass into smaller units, with intentional eating of high marrow elements at the butchering site and the movement of larger meat pieces to a larger residential camp for later consumption.

1. In December 1994, near the French village of Vallon-Pont-d'Arc, more than 300 images of animals and human hands painted during the Upper Paleolithic (about 30,000 years ago) were discovered.

2. The scale of the site is on par with other major examples of Paleolithic art, such as Lascaux (France) and Altamira (Spain).

3. Researchers are hopeful that the new discovery will provide insight into the evolution of human symbolism.

4. Of particular interest is the fact that the depictions included nongame animals (e.g., bears, rhinos, an owl, a hyena, and a panther), unlike the massive Lascaux site.

5. One prevailing hypothesis is that such caves served not as habitats, being too dark, but as ritual sites.