Poaceae Grasslands such as savannah and prairie where grasses are dominant are estimated to constitute 40.5% of the land area of the Earth, excluding Greenland and Antarctica.[6] Grasses are also an important part of the vegetation in many other habitats, including wetlands, forests and tundra. The Poaceae are the most economically important plant family, providing staple foods from domesticated cereal crops such as maize (corn), wheat, rice, barley, and millet as well as forage, building materials (bamboo, thatch, straw) and fuel (ethanol). Etymology[edit] Evolutionary history[edit] Grasses include some of the most versatile plant life-forms. Prior to 2005, fossil findings indicated that grasses evolved around 55 million years ago. Description[edit] Diagram of a typical lawn grass plant. Growth and development[edit] Grass blades grow at the base of the blade and not from elongated stem tips. Distribution[edit] Ecology[edit] Taxonomy[edit] Uses[edit] Food production[edit] Industry[edit] Sports turf[edit]
Homo rudolfensis Homo rudolfensis (also Australopithecus rudolfensis) is an extinct species of the Hominini tribe known only through a handful of representative fossils, the first of which was discovered by Bernard Ngeneo, a member of a team led by anthropologist Richard Leakey and zoologist Meave Leakey in 1972, at Koobi Fora on the east side of Lake Rudolf (now Lake Turkana) in Kenya. On 8 August 2012, a team led by Meave Leakey announced the discovery of a face and two jawbones belonging to H. rudolfensis. KNM-ER 1470[edit] UR 501 (original specimen), the oldest fossil of genus Homo The fossil KNM-ER 1470 was the center of much debate concerning its species. In March 2007, a team led by Timothy Bromage, an anthropologist at New York University, reconstructed the skull of KNM-ER 1470. 2012 fossil find[edit] See also[edit] References[edit] ^ Jump up to: a b В.П. External links[edit]
Baboon Taxonomy and phylogeny[edit] Five species of Papio are commonly recognized, although there is some disagreement about whether they are really full species or subspecies. They are P. ursinus (chacma baboon, found in southern Africa), P. papio (western, red, or Guinea baboon, found in the far western Africa), P. hamadryas (hamadryas baboon, found in the Horn of Africa and southwestern Arabia), P. anubis (olive baboon, found in the north-central African savanna) and P. cynocephalus (yellow baboon, found in south-central and eastern Africa). Many authors distinguish P. hamadryas as a full species, but regard all the others as subspecies of P. cynocephalus and refer to them collectively as "savanna baboons". This may not be helpful: it is based on the argument that the hamadryas baboon is behaviorally and physically distinct from other baboon species, and that this reflects a separate evolutionary history. The five species of baboons in the genus Papio are:[1] Anatomy and physiology[edit]
Primates A primate ( With the exception of humans, which inhabit every continent,[a] most primates live in tropical or subtropical regions of the Americas, Africa and Asia.[5] They range in size from Madame Berthe's mouse lemur, which weighs only 30 g (1 oz), to the eastern lowland gorilla, weighing over 200 kg (440 lb). Based on fossil evidence, the earliest known true primates, represented by the genus Teilhardina, date to 55.8 million years old.[6] An early close primate relative known from abundant remains is the Late Paleocene Plesiadapis, circa 55–58 million years old.[7] Molecular clock studies suggest that the primate branch may be even older, originating in the mid-Cretaceous period around 85 mya.[7] Considered generalist mammals, primates exhibit a wide range of characteristics. Some primates (including some great apes and baboons) are primarily terrestrial rather than arboreal, but all species possess adaptations for climbing trees. Historical and modern terminology[edit]
Pleistocene Charles Lyell introduced this term in 1839 to describe strata in Sicily that had at least 70% of their molluscan fauna still living today. This distinguished it from the older Pliocene Epoch, which Lyell had originally thought to be the youngest fossil rock layer. He constructed the name "Pleistocene" ("Most New" or "Newest") from the Greek πλεῖστος, pleīstos, "most", and καινός, kainós (latinized as cænus), "new";[2] this contrasting with the immediately preceding Pleiocene ("More New" or "Newer", from πλείων, pleíōn, "more", and kainós; usual spelling: Pliocene), and the immediately subsequent Holocene ("wholly new" or "entirely new", from ὅλος, hólos, "whole", and kainós) epoch, which extends to the present time. Dating[edit] The Pleistocene covers the recent period of repeated glaciations. The name Plio-Pleistocene has in the past been used to mean the last ice age. Paleogeography and climate[edit] Glacial features[edit] The effects of glaciation were global. Major events[edit]
Homo gautengensis Homo gautengensis is a hominin species proposed by biological anthropologist Darren Curnoe in 2010. The species is composed of South African hominin fossils previously attributed to Homo habilis, Homo ergaster or in some cases Australopithecus and is argued by Curnoe to be the earliest species in the genus Homo.[1] Discovery and analysis[edit] Analysis announced in May 2010 of a partial skull found decades earlier in South Africa's Sterkfontein Caves in Gauteng near Johannesburg identified the species, named Homo gautengensis by anthropologist Dr. Geochronology[edit] Identification of H. gautengensis was based on partial skulls, several jaws, teeth and other bones found at various times and cave sites in the Cradle of Humankind. Description[edit] Curnoe believes H. gautengensis stood just over 3 feet (0.91 m) tall and weighed about 110 pounds (50 kg). The researchers believe it lacked speech and language skills. Implications[edit] See also[edit] References[edit]
Gorilla Gorillas constitute the eponymous genus Gorilla, the largest extant genus of primates by physical size. They are ground-dwelling, predominantly herbivorous apes that inhabit the forests of central Africa. The genus is divided into two species and either four or five subspecies. The DNA of gorillas is highly similar to that of a human, from 95–99% depending on what is counted, and they are the next closest living relatives to humans after the chimpanzees (including bonobos). Gorillas' natural habitats cover tropical or subtropical forests in Africa. Etymology Evolution and classification Primatologists continue to explore the relationships between various gorilla populations.[8] The species and subspecies listed here are the ones upon which most scientists agree. The proposed third subspecies of Gorilla beringei, which has not yet received a trinomen, is the Bwindi population of the mountain gorilla, sometimes called the Bwindi gorilla. Physical characteristics A skull of a gorilla Nesting
Hominini Through DNA comparison, scientists believe the Pan / Homo divergence occurred between 5.4 and 6.3 million years ago, after an unusual process of speciation that ranged over 4 million years.[5] Few fossil specimens on the Pan side of the split have been found, the first fossil chimpanzee discovery being published in 2005,[6] dating to between 545 ± 3 kyr (thousand years) and 284 ± 12 kyr via Argon-argon dating, from Kenya's East African Rift Valley. All of the extinct genera listed in the table to the right are ancestral to Homo, or are offshoots of such. However, both Orrorin and Sahelanthropus existed around the time of the split, and so may be ancestral to all three extant species. In the proposal of Mann and Weiss (1996),[7] the tribe Hominini includes Pan as well as Homo, but within separate subtribes. Homo (and, by inference, all bipedal apes) is in the subtribe Hominina, while Pan is in the subtribe Panina. Wood (2010) discusses the different views of this taxonomy.[8]
Pliocene As with other older geologic periods, the geological strata that define the start and end are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The boundaries defining the Pliocene are not set at an easily identified worldwide event but rather at regional boundaries between the warmer Miocene and the relatively cooler Pleistocene. The upper boundary was set at the start of the Pleistocene glaciations. Etymology[edit] The Pliocene was named by Sir Charles Lyell. Subdivisions[edit] Piacenzian (3.600–2.588 Ma)Zanclean (5.332–3.600 Ma) The Piacenzian is sometimes referred to as the Late Pliocene, whereas the Zanclean is referred to as the Early Pliocene. In the system of North American Land Mammal Ages (NALMA) include Hemphillian (9–4.75 Ma), and Blancan (4.75–1.806 Ma). Climate[edit] Mid-Pliocene reconstructed annual sea surface temperature anomaly Paleogeography[edit] Sea level changes exposed the land-bridge between Alaska and Asia. Flora[edit] Titanis.
Homo habilis Homo habilis (also Australopithecus habilis) is a species of the Hominini tribe, which lived from approximately 2.33 to 1.44 million years ago, during the Gelasian Pleistocene period.[1] While there has been scholarly controversy regarding its placement in the genus Homo rather than the genus Australopithecus,[2][3] its brain size has been shown to range from 550 cm3 to 687 cm3, rather than from 363 cm3 to 600 cm3 as formerly thought.[3][4] These more recent findings concerning brain size favor its traditional placement in the genus Homo, as does the need for the genus to be monophyletic if H. habilis is indeed the common ancestor.[citation needed] Homo habilis has often been thought to be the ancestor of the more gracile and sophisticated Homo ergaster, which in turn gave rise to the more human-appearing species, Homo erectus. Findings[edit] KNM ER 1813[edit] OH 7[edit] OH 24[edit] KNM ER 1805[edit] Interpretations[edit] Homo habilis - Forensic facial reconstruction/approximation Notes[edit]
Orangutan Orangutans are the most arboreal of the great apes and spend most of their time in trees. Their hair is typically reddish-brown, instead of the brown or black hair typical of chimpanzees and gorillas. Males and females differ in size and appearance. Dominant adult males have distinctive cheek pads and produce long calls that attract females and intimidate rivals. Younger males do not have these characteristics and resemble adult females. Orangutans are the most solitary of the great apes, with social bonds occurring primarily between mothers and their dependent offspring, who stay together for the first two years. Orangutans are among the most intelligent primates; they use a variety of sophisticated tools and construct elaborate sleeping nests each night from branches and foliage. Etymology The word was first attested in English in 1691 in the form orang-outang, and variants with -ng instead of -n as in the Malay original are found in many languages. Taxonomy, phylogeny and genetics
Homo Homo is the genus of hominids that includes modern humans and species closely related to them. The genus is estimated to be about 2.3 to 2.4 million years old,[1][2] possibly having evolved from australopithecine ancestors, with the appearance of Homo habilis. Several species, including Australopithecus garhi, Australopithecus sediba, Australopithecus africanus, and Australopithecus afarensis, have been proposed as the direct ancestor of the Homo lineage.[3][4] These species have morphological features that align them with Homo, but there is no consensus on which gave rise to Homo, assuming it was not an as-yet undiscovered species. The most salient physiological development between the earlier australopith species and Homo is the increase in cranial capacity, from about 450 cm3 (27 cu in) in A. garhi to 600 cm3 (37 cu in) in H. habilis. Homo sapiens (modern humans) is the only surviving species in the genus, all others having become extinct. Naming[edit] Species[edit] See also[edit]
Miocene The Miocene /ˈmaɪəsiːn/ (symbol MI[1]) is the first geological epoch of the Neogene period and extends from about 23.03 to 5.332 million years ago (Ma). The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words μείων (meiōn, “less”) and καινός (kainos, “new”)[2] and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The earth went from the Oligocene through the Miocene and into the Pliocene as it cooled into a series of ice ages. The apes arose and diversified during the Miocene epoch, becoming widespread in the Old World. Subdivisions[edit] The Miocene faunal stages from youngest to oldest are typically named according to the International Commission on Stratigraphy:[5] These subdivisions within the Miocene are defined by the relative abundance of different species of calcareous nanofossils (calcite platelets shed by brown single-celled algae) and foraminifera (single-celled protists with diagnostic shells). Climate[edit]
Geologic time scale The geologic time scale (GTS) is a system of chronological measurement that relates stratigraphy to time, and is used by geologists, paleontologists, and other earth scientists to describe the timing and relationships between events that have occurred throughout Earth's history. The table of geologic time spans presented here agrees with the nomenclature, dates and standard color codes set forth by the International Commission on Stratigraphy. Evidence from radiometric dating indicates that the Earth is about 4.54 billion years old. The geology or deep time of Earth's past has been organized into various units according to events which took place in each period. Different spans of time on the GTS are usually delimited by changes in the composition of strata which correspond to them, indicating major geological or paleontological events, such as mass extinctions. Terminology[edit] History and nomenclature of the time scale[edit] Graphical representation of Earth's history as a spiral