Peopling the past: new perspectives on the ancient Maya. (1/37)

The new direction in Maya archaeology is toward achieving a greater understanding of people and their roles and their relations in the past. To answer emerging humanistic questions about ancient people's lives Mayanists are increasingly making use of new and existing scientific methods from archaeology and other disciplines. Maya archaeology is bridging the divide between the humanities and sciences to answer questions about ancient people previously considered beyond the realm of archaeological knowledge.  (+info)

Rapid prehistoric extinction of iguanas and birds in Polynesia. (2/37)

The Tongoleleka archaeological site on Lifuka Island, Kingdom of Tonga, is a rich accumulation of pottery, marine mollusks, and nonhuman bones that represents first human contact on a small island in Remote Oceania approximately 2,850 years ago. The lower strata contain decorated Lapita-style pottery and bones of an extinct iguana (Brachylophus undescribed sp.) and numerous species of extinct birds. The upper strata instead feature Polynesian Plainware pottery and bones of extant species of vertebrates. A stratigraphic series of 20 accelerator-mass spectrometer radiocarbon dates on individual bones of the iguana, an extinct megapode (Megapodius alimentum), and the non-native chicken (Gallus gallus) suggests that anthropogenic loss of the first two species and introduction of the latter occurred on Lifuka within a time interval too short (a century or less) to be resolved by radiometric dating. The geologically instantaneous prehistoric collapse of Lifuka's vertebrate community contrasts with the much longer periods of faunal depletion on some other islands, thus showing that the elapse time between human arrival and major extinction events was highly variable on oceanic islands as well as on continents.  (+info)

History of human parasitology. (3/37)

Humans are hosts to nearly 300 species of parasitic worms and over 70 species of protozoa, some derived from our primate ancestors and some acquired from the animals we have domesticated or come in contact with during our relatively short history on Earth. Our knowledge of parasitic infections extends into antiquity, and descriptions of parasites and parasitic infections are found in the earliest writings and have been confirmed by the finding of parasites in archaeological material. The systematic study of parasites began with the rejection of the theory of spontaneous generation and the promulgation of the germ theory. Thereafter, the history of human parasitology proceeded along two lines, the discovery of a parasite and its subsequent association with disease and the recognition of a disease and the subsequent discovery that it was caused by a parasite. This review is concerned with the major helminth and protozoan infections of humans: ascariasis, trichinosis, strongyloidiasis, dracunculiasis, lymphatic filariasis, loasis, onchocerciasis, schistosomiasis, cestodiasis, paragonimiasis, clonorchiasis, opisthorchiasis, amoebiasis, giardiasis, African trypanosomiasis, South American trypanosomiasis, leishmaniasis, malaria, toxoplasmosis, cryptosporidiosis, cyclosporiasis, and microsporidiosis.  (+info)

Climate and the collapse of Maya civilization. (4/37)

In the anoxic Cariaco Basin of the southern Caribbean, the bulk titanium content of undisturbed sediment reflects variations in riverine input and the hydrological cycle over northern tropical South America. A seasonally resolved record of titanium shows that the collapse of Maya civilization in the Terminal Classic Period occurred during an extended regional dry period, punctuated by more intense multiyear droughts centered at approximately 810, 860, and 910 A.D. These new data suggest that a century-scale decline in rainfall put a general strain on resources in the region, which was then exacerbated by abrupt drought events, contributing to the social stresses that led to the Maya demise.  (+info)

Infectious diseases in the 21st century: old challenges and new opportunities. (5/37)

Infectious diseases are the confrontation of two worlds, the microbial world and the world of human physiology. Although these two worlds are as a whole governed by the same laws of nature, they show substantial differences: the microbiological world is 1000 times older, and was initiated by the development of the archaea, the 'living organisms of the extreme': its biomass and its diversity are immense - two to three billion species or 60% of the total biomass of the planet. The number of pathogens that adapted to man, however, is extremely limited - barely 1000. Thus, over billions of years, an evolution of the microbial world took place from 'early life', characterized by chemosynthesis, to the 'modern pathogens', and entailed a dramatic 'concentration' of life conditions and an adaptation towards a narrow range of requirements - those allowing survival in the human body. Within the last two centuries, these two slowly evolving systems, microbial life and human life, were profoundly modified in an unprecedented manner by a third player, human civilization, with its global impact on the environment through physical, chemical, societal, and climatic determinants. An appreciation of the evolution of infectious diseases in the 21st century and of the development of new diagnostic and therapeutic strategies therefore requires a full understanding of these three domains: human physiology, microbiology, and the environment. This review will put major emphasis on the environmental role of civilization on infectious diseases before considering new opportunities to combat them through novel and creative solutions.  (+info)

Environmental and social influences on emerging infectious diseases: past, present and future. (6/37)

During the processes of human population dispersal around the world over the past 50 000-100 000 years, along with associated cultural evolution and inter-population contact and conflict, there have been several major transitions in the relationships of Homo sapiens with the natural world, animate and inanimate. Each of these transitions has resulted in the emergence of new or unfamiliar infectious diseases. The three great historical transitions since the initial advent of agriculture and livestock herding, from ca. 10 000 years ago, occurred when: (i) early agrarian-based settlements enabled sylvatic enzootic microbes to make contact with Homo sapiens; (ii) early Eurasian civilizations (such as the Greek and Roman empires, China and south Asia) came into military and commercial contact, ca. 3000-2000 years ago, swapping their dominant infections; and (iii) European expansionism, over the past five centuries, caused the transoceanic spread of often lethal infectious diseases. This latter transition is best known in relation to the conquest of the Americas by Spanish conquistadores, when the inadvertent spread of measles, smallpox and influenza devastated the Amerindian populations.Today, we are living through the fourth of these great transitional periods. The contemporary spread and increased lability of various infectious diseases, new and old, reflect the combined and increasingly widespread impacts of demographic, environmental, behavioural, technological and other rapid changes in human ecology. Modern clinical medicine has, via blood transfusion, organ transplantation, and the use of hypodermic syringes, created new opportunities for microbes. These have contributed to the rising iatrogenic problems of hepatitis C, HIV/AIDS and several other viral infections. Meanwhile, the injudicious use of antibiotics has been a rare instance of human action actually increasing 'biodiversity'. Another aspect of this fourth transition is that modern hyper-hygienic living restricts microbial exposure in early life. This, in the 1950s, may have contributed to an epidemic of more serious, disabling, poliomyelitis, affecting older children than those affected in earlier, more endemic decades. As with previous human-microbe transitions, a new equilibrial state may lie ahead. However, it certainly will not entail a world free of infectious diseases. Any mature, sustainable, human ecology must come to terms with both the need for, and the needs of, the microbial species that help to make up the interdependent system of life on Earth. Humans and microbes are not "at war"; rather, both parties are engaged in amoral, self-interested, coevolutionary struggle. We need to understand better, and therefore anticipate, the dynamics of that process.  (+info)

Helping the poor emerge from "urban barbarism to civic civilization": public bathhouses in America, 1890-1915. (7/37)

In an era when the luxury of private bathrooms had not yet been made widely available to the masses, local charities and municipal governments worked feverishly to construct public bathhouses. Reformers, including city officials, engineers, physicians, and members of the clergy, increased the number of public bath facilities across America from a mere six in 1894 to 49 by 1904. The urban poor took tens of millions of showers at the turn of the century as a result. What the poor may not have realized, however, is that the reformers of the Progressive Era had in mind a form of social engineering. Bathing, they argued, not only assisted in the containment of disease; it also served to instill upper-middle class values of self-respect, morality, and citizenship into the life and practice of the poor.  (+info)

Burning down the brewery: establishing and evacuating an ancient imperial colony at Cerro Baul, Peru. (8/37)

Before the Inca reigned, two empires held sway over the central Andes from anno Domini 600 to 1000: the Wari empire to the north ruled much of Peru, and Tiwanaku to the south reigned in Bolivia. Face-to-face contact came when both colonized the Moquegua Valley sierra in southern Peru. The state-sponsored Wari incursion, described here, entailed large-scale agrarian reclamation to sustain the occupation of two hills and the adjacent high mesa of Cerro Baul. Monumental buildings were erected atop the mesa to serve an embassy-like delegation of nobles and attendant personnel that endured for centuries. Final evacuation of the Baul enclave was accompanied by elaborate ceremonies with brewing, drinking, feasting, vessel smashing, and building burning.  (+info)