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Species across the world are rapidly going extinct due to human activities, but humans are also causing rapid evolution and the emergence of new species. A new study published today summarises the causes of humanmade speciation, and discusses why newly evolved species cannot simply replace extinct wild species. The study was led by the Center for Macroecology, Evolution and Climate at the University of Copenhagen.

A growing number of examples show that humans not only contribute to the extinction of species but also drive evolution, and in some cases the emergence of entirely new species. This can take place through mechanisms such as accidental introductions, domestication of animals and crops, unnatural selection due to hunting, or the emergence of novel ecosystems such as the urban environment.

Although tempting to conclude that human activities thus benefit as well as deplete global biodiversity, the authors stress that extinct wild species cannot simply be replaced with newly evolved ones, and that nature conservation remains just as urgent.

"The prospect of 'artificially' gaining novel species through human activities is unlikely to elicit the feeling that it can offset losses of 'natural' species. Indeed, many people might find the prospect of an artificially biodiverse world just as daunting as an artificially impoverished one" says lead author and Postdoc Joseph Bull from the Center for Macroecology, Evolution and Climate at the University of Copenhagen.

The study which was carried out in collaboration with the University of Queensland was published in >Proceedings of Royal Society B. It highlights numerous examples of how human activities influence species' evolution. For instance: as the common house mosquito adapted to the environment of the underground railway system in London, it established a subterranean population. Now named the 'London Underground mosquito', it can no longer interbreed with its above ground counterpart and is effectively thought to be a new species.

"We also see examples of domestication resulting in new species. According to a recent study, at least six of the world's 40 most important agricultural crops are considered entirely new" explains Joseph Bull.

Furthermore, unnatural selection due to hunting can lead to new traits emerging in animals, which can eventually lead to new species, and deliberate or accidental relocation of species can lead to hybridization with other species. Due to the latter, more new plant species in Europe have appeared than are documented to have gone extinct over the last three centuries.

Although it is not possible to quantify exactly how many speciation events have been caused through human activities, the impact is potentially considerable, the study states.

"In this context, 'number of species' becomes a deeply unsatisfactory measure of conservation trends, because it does not reflect many important aspects of biodiversity. Achieving a neutral net outcome for species numbers cannot be considered acceptable if weighing wild fauna against relatively homogenous domesticated species. However, considering speciation alongside extinction may well prove important in developing a better understanding of our impact upon global biodiversity. We call for a discussion about what we, as a society, actually want to conserve about nature" says Associate Professor Martine Maron from the University of Queensland.

Researchers do agree that current extinction rates may soon lead to a 6th period of mass extinction. Since the last Ice Age, 11.500 years ago, it is estimated that 255 mammals and 523 bird species has gone extinct, often due to human activity. In the same period, humans have relocated almost 900 known species and domesticated more than 470 animals and close to 270 plant species.

Source: Faculty of Science - University of Copenhagen [June 28, 2016]

With scientists forecasting sea levels to rise by anywhere from several inches to several feet by 2100, historic structures and coastal heritage sites around the world are under threat. Some sites and artifacts could become submerged.

Scientists, historic preservationists, architects and public officials are meeting this week in Newport, Rhode Island—one of the threatened areas—to discuss the problem, how to adapt to rising seas and preserve historic structures.

"Any coastal town that has significant historic properties is going to be facing the challenge of protecting those properties from increased water and storm activity," said Margot Nishimura, of the Newport Restoration Foundation, the nonprofit group hosting the conference.

Federal authorities have encouraged people to elevate structures in low-lying areas, but that poses challenges in dense neighborhoods of centuries-old homes built around central brick chimneys, Nishimura said, especially ones where preservationists are trying to keep the character intact.

Many of the most threatened sites in North America lie along the East Coast between Cape Hatteras, North Carolina, and southern Maine, where the rate of sea level rise is among the fastest in the world, said Adam Markham, of the Union of Concerned Scientists, a speaker at the conference.

"We're actually not going to be able to save everything," he said.

A look at some of the historic areas and cultural sites that are under threat from rising sea levels:

Statue of Liberty and Ellis Island

Situated in New York Harbor, the Statue of Liberty and Ellis Island are some of New York's most important tourist attractions.

In 2012, Superstorm Sandy submerged most of the low-elevation Liberty and Ellis islands. After the storm, the Statue of Liberty, a gift from the people of France in 1886, was closed for eight months. Ellis Island, the entry point for about 12 million immigrants to the United States from 1892 to 1954, remained closed for nearly a year.

A report by the National Park Service looked at how several parks would be threatened by 1 meter, or around 3 feet, of sea level rise. It found $1.51 billion worth of assets at the Statue of Liberty National Monument were highly exposed to sea level rise.

Much of historic Boston is along the water and is at risk due to sea level rise, including Faneuil Hall, the market building known as the "Cradle of Liberty," and parts of the Freedom Trail, a walking trail that links historic sites around the city.

Boston has seen a growing number of flooding events in recent years, up from two annually in the 1970s to an average of 11 annually between 2009 and 2013, according to a 2014 report by the Union of Concerned Scientists. If sea levels rise by 5 inches, the group reported, the number of floods is projected to grow to 31 annually. If seas rise by 11 inches, the number of flooding events is projected to rise to 72 per year.

Newport

The Point neighborhood in the Rhode Island resort town has one of the highest concentrations of Colonial houses in the United States, and it sits 4 feet above mean sea level. Tidal flooding is already occurring in the neighborhood, and that is expected to increase as sea levels rise, Nishimura said. The smell of sea water already permeates the basement of some homes.

Annapolis

Maryland's capital, on Chesapeake Bay, boasts the nation's largest concentration of 18th-century brick buildings. The city briefly served as the nation's capital in the post-Revolutionary War period, and the Treaty of Paris, which formally ended the war, was ratified there. The city is also home to the U.S. Naval Academy.

The city already sees tidal flooding dozens of times a year, and scientists have predicted number could rise to hundreds annually in the next 30 years.

Jamestown

Established in 1607, it is the first permanent English colony in North America. It sits along the tidal James River in Virginia, and most of the settlement is less than 3 feet above sea level. A large part of the settlement has already eroded because of wave action, Markham said. Storms have also damaged the site, including Hurricane Isabel in 2003, which flooded nearly 1 million artifacts. A rising water table at the site also poses a threat to archaeological remains, Markham said.

He called the loss of archaeological artifacts "an urgent problem" along the U.S. coastline.

Hawaii

Reports by the National Park Service and others have found that rising sea level rises threaten archaeological sites at various historic places in Hawaii. Those include ancient fish ponds at Pu'ukohola Heiau National Historic Site and a "Great Wall" at a sacred site in Pu'uhonua o Honaunau National Historical Park. It is considered the best-preserved such wall in Hawaii.

International Sites

Dozens of UNESCO World Heritage Sites are under threat from sea level rise, according to a 2014 report by climate scientists Ben Marzeion, of the University of Innsbruck in Austria, and Anders Levermann, of the Potsdam Institute in Germany.

Among those are: the Tower of London; Robben Island in South Africa, where Nelson Mandela was imprisoned for 27 years; Venice, Italy, and its lagoon; Mont-Saint-Michel, home to an abbey built atop a rocky islet in France; the Kasbah of Algiers, Algeria; the historic district of Old Quebec, Canada; Old Havana in Cuba; and archaeological areas of Pompeii, Italy, and Carthage in Tunisia.

The authors wrote that their findings indicate that "fundamental decisions with regard to mankind's cultural heritage are required."

Author: Michelle R. Smith | Source: The Associated Press [April 11, 2016]

The reunification of ancient Egypt achieved by Nebhepetre Mentuhotep II—the first pharaoh of the Middle Kingdom—was followed by a great cultural flowering that lasted nearly 400 years. During the Middle Kingdom (mid-Dynasty 11–Dynasty 13, around 2030–1650 B.C.), artistic, cultural, religious, and political traditions first conceived and instituted during the Old Kingdom were revived and reimagined.

This transformational era will be represented through 230 powerful and compelling masterworks (individual objects and groups of objects) in the major international exhibition Ancient Egypt Transformed: The Middle Kingdom, opening October 12 at New York’s Metropolitan Museum of Art. Fashioned with great subtlety and sensitivity, and ranging in size from monumental stone sculptures to delicate examples of jewelry, the works of art are drawn from the preeminent collection of the Metropolitan—which is particularly rich in Middle Kingdom material—and 37 museums and collections in North America and Europe. This is the first comprehensive presentation of Middle Kingdom art and culture and features many objects that have never been shown in the United States.

“The astonishing continuity of ancient Egyptian culture, with certain basic principles lasting for thousands of years, gives the impression of changelessness,” said Adela Oppenheim, Curator of Egyptian Art. “But the works of art in the exhibition will show that ancient Egypt constantly evolved, and was remarkably flexible within a consistent framework. New ideas did not simply replace earlier notions; they were added to what had come before, creating a fascinating society of ever-increasing complexity.”

Arranged thematically and chronologically, the exhibition opens with a forceful, monumental statue of King Mentuhotep II, carved in an intentionally archaic style that suggests a link to the legendary kings of early Egypt (ca. 3300 B.C.).

Profound changes in the concept of kingship are demonstrated through a series of royal statues that span several hundred years. Early Middle Kingdom pharaohs are often depicted with youthful faces and confident expressions. In contrast, the evocative, fleshy faces and deep-set, hooded eyes of later kings present startling images of maturity and humanity.

During the 12th Dynasty, the construction of pyramid complexes resumes, after a lapse of more than a century. The innovation found in these complexes is exemplified by that of Senwosret III (around 1878-1840 B.C.) at Dahshur, site of Metropolitan Museum excavations since 1990. A detailed 1-to-150 scale model made by Ron Street, Supervisor of the Museum’s Three-Dimensional Imaging, Prototyping, and Molding Studio, will show the original form of the complex.

Royal women were always closely connected to the pharaoh, as evidenced by the placement of their burials and chapels near those of the king. Although less is known about Middle Kingdom queens and princesses, indicating altered or perhaps diminished roles during the era, some of the finest ancient Egyptian jewelry was produced for elite women of the time. Inscriptions and symbolic motifs endowed the jewelry with spiritual power and related to the role these women played in supporting the kings as guarantors of divine order on earth.

During the Middle Kingdom, members of all levels of Egyptian society commissioned a wider variety of works of art and constructed commemorative chapels at significant holy sites; statues of squatting figures rendered in a cubic, block-like form and statues in an attitude of prayer originate during this period.

Thematic groupings of artifacts from domestic settings, tombs, and temples reveal the breadth of artistic expression, evolution of styles, and the transformation of many aspects of Egyptian culture and religion. First attested in the Middle Kingdom are a variety of intriguing, protective magical objects, notably some that were believed to shield pregnant women and young children. Among them are curved hippopotamus tusks that are unique to this era and are covered with images of beneficial supernatural beings.

The family was always a central element of ancient Egyptian culture, but in the Middle Kingdom larger groups of relatives are depicted together on stelae and sculptures. One remarkable stela on view features depictions of 30 individuals. Others include poignant groupings of mothers and their young children.

Significant changes in afterlife beliefs during the Middle Kingdom are manifest in new kinds of objects present in burials. Intricately and finely rendered miniatures of painted wood (so-called models) from the tomb of the chancellor Meketre (ca. 1980–75 B.C.), excavated by the Metropolitan in 1920, depict food production, manufacturing, and journeys by boat; they are displayed in several sections of the exhibition.

During the Middle Kingdom, the god Osiris gained importance as a funerary deity and, from then on, the dead at all levels of society became manifestations of the god. Because Osiris functioned as the ruler of the underworld, certain symbols and regalia that had been the sole prerogative of the reigning king were appropriated for non-royal use: mummies sometimes had a uraeus on the brow (a stylized cobra usually seen on a pharaoh’s crown), and a flail (a standard attribute of the pharaoh) could be placed inside a coffin. Canopic jars, which held the organs of the deceased, became much more ornate in the Middle Kingdom. With lids in the form of human heads, the vessels are small sculptures in their own right.

As devotion to Osiris increased, his cult center at Abydos (north of Luxor) gained prominence. Annual processions were held between his temple and his supposed burial place in the desert to the west. To participate eternally in these elaborate rites and ensure their afterlife, individuals at many levels of society erected memorial chapels—some with outstanding artworks—for themselves and their families along the procession route.

Deity temples—largely built of fragile mud brick in the Old Kingdom—were transformed dramatically during the Middle Kingdom, when pharaohs commissioned decorated stone temples throughout the country. Decoration included spectacular sculpture and reliefs depicting the pharaoh presenting offerings to and revering deities, as well as statues of the gods.

Colossal statues were first made during the Old Kingdom, but they became much more common during the Middle Kingdom. Portions of colossal statues will be displayed throughout the exhibition, with the largest in scale being presented at its conclusion: a monumental head of pharaoh Amenemhat III that was transported to the Delta city of Bubastis and reused by later kings. The same happened to the colossal statue of a mid-Dynasty 12 king, on loan from the Ägyptisches Museum und Papyrussammlung, Berlin, and on view in the Museum’s Great Hall. Pharaohs after the Middle Kingdom reused the monuments of their predecessors, particularly those of the Middle Kingdom, both for economy and to link themselves to the past.

General knowledge of the history of the Middle Kingdom—the achievements of its artists, its religious beliefs, burial customs, and relationships with other lands—stems in large part from Metropolitan Museum sponsorship of numerous excavations at Middle Kingdom sites including Deir el-Bahri (1920–31), Lisht (1906–34, 1984–91), and Dahshur (1990–present).

Source: The Metropolitan Museum of Art [September 26, 2015]