Cucurbita pepo is a cultivated plant of the genus Cucurbita. It yields varieties of squash and pumpkin, but the most widespread varieties belong to Cucurbita pepo subsp. It has been domesticated in the New World for thousands of years, some authors maintain that C. pepo is derived from C. texana, while others suggest that C. texana is merely feral C. pepo. They have a variety of uses, especially as a food source. C. pepo seems more closely related to C. fraterna, though disagreements exist about the nature of that connection. The morphological differences within the species C. pepo are so vast, its various subspecies and these vast differences are rooted in its widespread geographic distribution. C. pepo is one of the oldest, if not the oldest domesticated species, the oldest known locations are in southern Mexico in Oaxaca 8, 000-10,000 years ago and Ocampo, Mexico about 7,000 years ago. Its ancient territory extended north into Texas and up the Greater Mississippi River Valley into Illinois and east to Florida and it is known to have appeared in Missouri at least 4,000 years ago.
Some varieties grow in regions and some in moist regions. Debates about the origin of C. pepo have been going on since at least 1857, two opposing theories are given about its origin, 1) C. pepo is a direct descendant of C. texana and 2) C. texana is feral C. pepo. C. pepo may have appeared in the Old World prior to moving from Mexico into South America and it is found from sea level to slightly above 2,000 m. Leaves have three to five lobes and are 20–35 cm wide, all the subspecies and cultivars are conspecific and interfertile. They are associated with C. fraterna or a still unknown ancestral specimen in southern Mexico, wild C. pepo is still found in the same areas as C. fraterna in Mexico. C. pepo has more similarities to C. fraterna than it does to C. texana, all studied C. fraterna alleles are found in C. pepo. Consequently, C. fraterna is the nearest relative of C. pepo, C. pepo is most likely an early domesticated form of C. fraterna. It crosses well with both C. pepo and C. texana, unlike most wild Cucurbita species, some fruit specimens of C. fraterna have been found that were not bitter.
Its usual habitat is dry scrub areas. C. pepo could be a compilospecies of C. fraterna and C. texana, C. fraterna is genetically closer to the first group and C. texana is genetically closer to the second group
The prefix paleo- comes from the Greek adjective palaios, meaning old or ancient. The term Paleo-Indians applies specifically to the period in the Western Hemisphere and is distinct from the term Paleolithic. Evidence suggests big-animal hunters crossed the Bering Strait from Eurasia into North America over a land and ice bridge, small isolated groups of hunter-gatherers migrated alongside herds of large herbivores far into Alaska. From c. 16,500 – c. 13,500 BCE, ice-free corridors developed along the Pacific coast and this allowed animals, followed by humans, to migrate south into the interior. The people went on foot or used primitive boats along the coastline, the precise dates and routes of the peopling of the New World are subject to ongoing debate. Stone tools, particularly projectile points and scrapers, are the evidence of the earliest human activity in the Americas. Crafted lithic flaked tools are used by archaeologists and anthropologists to classify cultural periods, scientific evidence links Indigenous Americans to Asian peoples, specifically eastern Siberian populations.
There is evidence for at least two separate migrations, between 8000–7000 BCE the climate stabilized, leading to a rise in population and lithic technology advances, resulting in more sedentary lifestyle. The specifics of Paleo-Indian migration to and throughout the Americas, including the dates and routes traveled, are subject to ongoing research. These people are believed to have followed herds of now-extinct pleistocene megafauna along ice-free corridors that stretched between the Laurentide and Cordilleran ice sheets, another route proposed is that, either on foot or using primitive boats, they migrated down the Pacific coast to South America. Evidence of the latter would since have been covered by a sea rise of hundreds of meters following the last ice age. Archaeologists contend that Paleo-Indians migration out of Beringia, ranges from c. 40,000 – c. 16,500 years ago and this time range is a source of debate and promises to continue as such for years to come. However, alternative theories about the origins of Paleoindians exist, including migration from Europe, the Paleo-Indian would eventually flourish all over the Americas.
These peoples were spread over a geographical area, thus there were regional variations in lifestyles. However, all the groups shared a common style of stone tool production, making knapping styles. Food would have been plentiful during the few months of the year. Lakes and rivers were teeming with many species of fish, nuts and edible roots could be found in the forests and marshes. The fall would have been a time because foodstuffs would have to be stored
Glossary of leaf morphology
The following is a defined list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple or compound, the edge of the leaf may be regular or irregular, may be smooth or bearing hair, bristles or spines. For more terms describing other aspects of leaves besides their overall morphology see the leaf article, leaves of most plants include a flat structure called the blade or lamina, but not all leaves are flat, some are cylindrical. Leaves may be simple, with a leaf blade, or compound. In flowering plants, as well as the blade of the leaf, there may be a petiole and stipules, leaf structure is described by several terms that include, Being one of the more visible features, leaf shape is commonly used for plant identification. Edge and margin are both interchangeable in the sense that they refer to the perimeter of a leaf. Leaves may be folded or rolled in various ways, the folding of leaves within a bud is vernation, ptyxis is the folding of an individual leaf in a bud
The Pennsylvanian is, in the ICS geologic timescale, the younger of two subperiods of the Carboniferous Period. It lasted from roughly 323.2 million years ago to 298.9 million years ago Ma. As with most other units, the rock beds that define the Pennsylvanian are well identified. The Pennsylvanian is named after the U. S. state of Pennsylvania, the division between Pennsylvanian and Mississippian comes from North American stratigraphy. In Europe, the Mississippian and Pennsylvanian are one continuous sequence of lowland continental deposits and are grouped together as the Carboniferous Period. The current internationally used geologic timescale of the ICS gives the Mississippian and Pennsylvanian the rank of subperiods, all modern classes of fungi have been found in rocks of Pennsylvanian age. Amphibians were diverse and common, some were several meters long as adults, the collapse of the rainforest ecology in the mid Pennsylvanian removed many amphibian species that did not survive as well in the cooler, drier conditions.
Reptiles, prospered due to specific key adaptations, one of the greatest evolutionary innovations of the Carboniferous was the amniote egg, which allowed for the further exploitation of the land by certain tetrapods. These included the earliest sauropsid reptiles, and the earliest known synapsid, small lizard-like animals quickly gave rise to many descendants. Reptiles underwent an evolutionary radiation, in response to the drier climate that followed the rainforest collapse. The Pennsylvanian has been variously subdivided, the Missourian or Monongahela corresponds to the rest of the Kasimovian. The Desmoinesian or Allegheny corresponds to the half of the Moscovian. The Atokan or upper Pottsville corresponds to the half of the Moscovian. The Morrowan corresponds to the Bashkirian, in the European subdivision, the Carboniferous is divided into two epochs and Silesian. The Silesian starts earlier than the Pennsylvanian and is divided in three ages, Namurian Westphalian Stephanian, the Late Carboniferous a Time of Great Coal Swamps, Paleomap project.
World map from this time period, the Carboniferous -354 to 290 Million Years Ago, University of California Museum of Paleontology. Information on stratigraphies, localities and life, the Pennsylvanian Epoch of the Carboniferous Period,318 to 299 Mya, Paleos. com US Geological Survey comparison of time scales
The Internet Archive launched the Wayback Machine in October 2001. It was set up by Brewster Kahle and Bruce Gilliat, and is maintained with content from Alexa Internet, the service enables users to see archived versions of web pages across time, which the archive calls a three dimensional index. Since 1996, the Wayback Machine has been archiving cached pages of websites onto its large cluster of Linux nodes and it revisits sites every few weeks or months and archives a new version. Sites can be captured on the fly by visitors who enter the sites URL into a search box, the intent is to capture and archive content that otherwise would be lost whenever a site is changed or closed down. The overall vision of the machines creators is to archive the entire Internet, the name Wayback Machine was chosen as a reference to the WABAC machine, a time-traveling device used by the characters Mr. Peabody and Sherman in The Rocky and Bullwinkle Show, an animated cartoon. These crawlers respect the robots exclusion standard for websites whose owners opt for them not to appear in search results or be cached, to overcome inconsistencies in partially cached websites, Archive-It.
Information had been kept on digital tape for five years, with Kahle occasionally allowing researchers, when the archive reached its fifth anniversary, it was unveiled and opened to the public in a ceremony at the University of California, Berkeley. Snapshots usually become more than six months after they are archived or, in some cases, even later. The frequency of snapshots is variable, so not all tracked website updates are recorded, Sometimes there are intervals of several weeks or years between snapshots. After August 2008 sites had to be listed on the Open Directory in order to be included. As of 2009, the Wayback Machine contained approximately three petabytes of data and was growing at a rate of 100 terabytes each month, the growth rate reported in 2003 was 12 terabytes/month, the data is stored on PetaBox rack systems manufactured by Capricorn Technologies. In 2009, the Internet Archive migrated its customized storage architecture to Sun Open Storage, in 2011 a new, improved version of the Wayback Machine, with an updated interface and fresher index of archived content, was made available for public testing.
The index driving the classic Wayback Machine only has a bit of material past 2008. In January 2013, the company announced a ground-breaking milestone of 240 billion URLs, in October 2013, the company announced the Save a Page feature which allows any Internet user to archive the contents of a URL. This became a threat of abuse by the service for hosting malicious binaries, as of December 2014, the Wayback Machine contained almost nine petabytes of data and was growing at a rate of about 20 terabytes each week. Between October 2013 and March 2015 the websites global Alexa rank changed from 162 to 208, in a 2009 case, Netbula, LLC v. Chordiant Software Inc. defendant Chordiant filed a motion to compel Netbula to disable the robots. Netbula objected to the motion on the ground that defendants were asking to alter Netbulas website, in an October 2004 case, Telewizja Polska USA, Inc. v. Echostar Satellite, No.02 C3293,65 Fed. 673, a litigant attempted to use the Wayback Machine archives as a source of admissible evidence, Telewizja Polska is the provider of TVP Polonia and EchoStar operates the Dish Network
The term Woodland Period was introduced in the 1930s as a generic term for prehistoric sites falling between the Archaic hunter-gatherers and the agriculturalist Mississippian cultures. The Eastern Woodlands cultural region covers what is now eastern Canada south of the Subarctic region and this period is variously considered a developmental stage, a time period, a suite of technological adaptations or traits, and a family tree of cultures related to earlier Archaic cultures. Many Woodland peoples used spears and atlatls until the end of the period, the most cited technological distinction of this period was the widespread use of pottery, and the diversification of pottery forms and manufacturing practices. Intensive agriculture characterizes the Mississippian period from ca, 1000-1400 CE and may have continued up to European contact, around 500 years ago. Eastern Woodlands lived in wigwams and longhouses, clay for pottery was typically tempered with grit or limestone. Pots were usually made in a conoidal or conical jars with rounded shoulders, slightly constricted necks, pots were coiled and paddled entirely by hand without the use of fast rotation such as a pottery wheel.
Some were slipped or brushed with red ochre, pottery and permanent settlements have often been thought of the three defining characteristics of the Woodland period. Nevertheless, these sites were typical Archaic settlements, differing only in the use of basic ceramic technology. Most of these are evident in the Southeastern United States by 1000 BCE, in some areas, like South Carolina and coastal Georgia, Deptford culture pottery manufacture ceased after ca.700 CE. In coastal regions, many settlements were near the coast, often near salt marshes, people tended to settle along rivers and lakes in both coastal and interior regions for maximum access to food resources. Most groups relied heavily on white-tailed deer, but a variety of small and large mammals were hunted also, including beaver, raccoon. Shellfish formed an important part of the diet, attested to by numerous shell middens along the coast, seasonal foraging characterized the strategies of many interior populations, with groups moving strategically among dense resource areas.
Recently evidence has accumulated of a reliance of woodland peoples on cultivation in this period, at least in some localities. This is especially true for the middle period and perhaps beyond. C. Margaret Scarry states in the Woodland periods, people diversified their use of plant foods, increased their consumption of starchy foods. They did so, however, by cultivating starchy seeds rather than by gathering more acorns and Yarnell refer to an indigenous crop complex as early as 3800 B. P. in parts of the region. The beginning of the Middle Woodland saw a shift of settlement to the Interior, as the Woodland period progressed and inter-regional trade of exotic materials greatly increased to the point where a trade network covered most of the Eastern United States. Throughout the Southeast and north of the Ohio River, burial mounds of important people were very elaborate and contained a variety of mortuary gifts, the most archaeologically certifiable sites of burial during this time were in Illinois and Ohio
The Clovis culture appears around 11, 500–11,000 uncal RCYBP, at the end of the last glacial period, and is characterized by the manufacture of Clovis points and distinctive bone and ivory tools. Archaeologists most precise determinations at present suggest that this age is equal to roughly 13,200 to 12,900 calendar years ago. Clovis people are considered to be the ancestors of most of the cultures of the Americas. The only human burial that has been associated with tools from the Clovis culture included the remains of an infant boy named Anzick-1. Researchers from the United States and Europe conducted paleogenetic research on Anzick-1s ancient nuclear, the results of these analyses reveal that Anzick-1 is closely related to modern Native American populations, which lends support to the Beringia hypothesis for the peopling of the Americas. The Clovis culture was replaced by more localized regional cultures from the time of the Younger Dryas cold climate period onward. Post-Clovis cultures include the Folsom tradition, Suwannee-Simpson, Plainview-Goshen, each of these is commonly thought to derive directly from Clovis, in some cases apparently differing only in the length of the fluting on their projectile points.
Recent preliminary carbon dating shows a culture from around or prior to 13,000 years ago, along with horse, camel, a hallmark of the toolkit associated with the Clovis culture is the distinctively shaped, fluted stone spear point, known as the Clovis point. The Clovis point is bifacial and typically fluted on both sides, the culture was originally named for a small number of artifacts found between 1932 and 1936 at Blackwater Locality No. 1, a site between the towns of Clovis and Portales, New Mexico. These finds were deemed especially important due to their association with mammoth sp. Clovis sites have since been identified throughout much, but not all, of the contiguous United States, as well as Mexico and Central America and it is generally accepted that Clovis people hunted mammoths, as Clovis points have repeatedly been found in sites containing mammoth remains. In total, more than 125 species of plants and animals are known to have used by Clovis people in the portion of the Western Hemisphere they inhabited.
The oldest Clovis site in North America is believed to be El Fin del Mundo in northwestern Sonora, Mexico and it features occupation dating around 13,390 calibrated years BP. In 2011, remains of Gomphothere were found, the evidence suggests that humans did in fact two of them here. Theres the Aubrey site in Denton County, which produced a date that is almost identical. After this time, Clovis-style fluted points were replaced by other fluted-point traditions with an uninterrupted sequence across North. An effectively continuous cultural adaptation proceeds from the Clovis period through the ensuing Middle, whether the Clovis culture drove the mammoth, and other species, to extinction via overhunting – the so-called Pleistocene overkill hypothesis – is still an open, and controversial, question
Radiocarbon dating is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was developed by Willard Libby in the late 1940s, Libby received the Nobel Prize for his work in 1960. The radiocarbon dating method is based on the fact that radiocarbon is constantly being created in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting radiocarbon combines with oxygen to form radioactive carbon dioxide. When the animal or plant dies, it stops exchanging carbon with its environment, and from that point onwards the amount of 14C it contains begins to decrease as the 14C undergoes radioactive decay. Measuring the amount of 14C in a sample from a plant or animal such as a piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died. The idea behind radiocarbon dating is straightforward, but years of work were required to develop the technique to the point where accurate dates could be obtained.
Research has been ongoing since the 1960s to determine what the proportion of 14C in the atmosphere has been over the past fifty thousand years. The resulting data, in the form of a curve, is now used to convert a given measurement of radiocarbon in a sample into an estimate of the samples calendar age. Other corrections must be made to account for the proportion of 14C in different types of organisms, additional complications come from the burning of fossil fuels such as coal and oil, and from the above-ground nuclear tests done in the 1950s and 1960s. Conversely, nuclear testing increased the amount of 14C in the atmosphere, measurement of radiocarbon was originally done by beta-counting devices, which counted the amount of beta radiation emitted by decaying 14C atoms in a sample. The development of dating has had a profound impact on archaeology. In addition to permitting more accurate dating within archaeological sites than previous methods, histories of archaeology often refer to its impact as the radiocarbon revolution.
Radiocarbon dating has allowed key transitions in prehistory to be dated, such as the end of the last ice age, and they synthesized 14C using the laboratorys cyclotron accelerator and soon discovered that the atoms half-life was far longer than had been previously thought. This was followed by a prediction by Serge A. Korff, employed at the Franklin Institute in Philadelphia and it had previously been thought that 14C would be more likely to be created by deuterons interacting with 13C. At some time during World War II, Willard Libby, who was at Berkeley, learned of Korffs research, in 1945, Libby moved to the University of Chicago where he began his work on radiocarbon dating. He published a paper in 1946 in which he proposed that the carbon in living matter might include 14C as well as non-radioactive carbon, by contrast, methane created from petroleum showed no radiocarbon activity because of its age. The results were summarized in a paper in Science in 1947, Libby and James Arnold proceeded to test the radiocarbon dating theory by analyzing samples with known ages
National Park Service
It was created on August 25,1916, by Congress through the National Park Service Organic Act and is an agency of the United States Department of the Interior. As of 2014, the NPS employs 21,651 employees who oversee 417 units, the National Park Service celebrated its centennial in 2016. National parks and national monuments in the United States were originally individually managed under the auspices of the Department of the Interior, the movement for an independent agency to oversee these federal lands was spearheaded by business magnate and conservationist Stephen Mather, as well as J. Horace McFarland. With the help of journalist Robert Sterling Yard, Mather ran a publicity campaign for the Department of the Interior and they wrote numerous articles that praised the scenic and historic qualities of the parks and their possibilities for educational and recreational benefits. This campaign resulted in the creation of a National Park Service, Mather became the first director of the newly formed NPS.
On March 3,1933, President Herbert Hoover signed the Reorganization Act of 1933, the act would allow the President to reorganize the executive branch of the United States government. It wasnt until that summer when the new President, Franklin D. Roosevelt, President Roosevelt agreed and issued two Executive orders to make it happen. In 1951, Conrad Wirth became director of the National Park Service, the demand for parks after the end of the World War II had left the parks overburdened with demands that could not be met. In 1952, with the support of President Dwight D. Eisenhower, he began Mission 66, New parks were added to preserve unique resources and existing park facilities were upgraded and expanded. In 1966, as the Park Service turned 50 years old, emphasis began to turn from just saving great and wonderful scenery, Director George Hartzog began the process with the creation of the National Lakeshores and National Recreation Areas. Since its inception in 1916, the National Park Service has managed each of the United States national parks, Yellowstone National Park was the first national park in the United States.
In 1872, there was no government to manage it. Yosemite National Park began as a park, the land for the park was donated by the federal government to the state of California in 1864 for perpetual conservation. Yosemite was returned to federal ownership, at first, each national park was managed independently, with varying degrees of success. In Yellowstone, the staff was replaced by the U. S. Army in 1886. Due to the irregularities in managing these national treasures, Stephen Mather petitioned the government to improve the situation. In response, Secretary of the Interior Franklin K. Lane challenged him to lobby for creating a new agency, Mather was successful with the ratification of the National Park Service Organic Act in 1916. Later, the agency was given authority over other protected areas, the National Park System includes all properties managed by the National Park Service