Problem: The number of species invasions has been on the rise at least since the beginning of the 1900s. Species are increasingly being moved by humans (on purpose and accidentally). In some cases the invaders are causing drastic changes and damage to their new habitats (e.g.: zebra mussels and the emerald ash borer in the Great Lakes region and the lion fish along the North American Atlantic coast). Some evidence suggests that invasive species are competitive in their new habitats because they are subject to less pathogen disturbance. Others report confounding evidence that occasionally suggest that species-rich communities harbor many native and exotic species simultaneously while some say that diverse ecosystems are more resilient and resist invasive plants and animals. An important question is, "do invasive species cause extinctions?" Many studies cite effects of invasive species on natives, but not extinctions. Invasive species seem to increase local (i.e.: alpha diversity) diversity, which decreases turnover of diversity (i.e.: beta diversity). Overall gamma diversity may be lowered because species are going extinct because of other causes, but even some of the most insidious invaders (e.g.: Dutch elm disease, emerald ash borer, chestnut blight in North America) have not caused their host species to become extinct. Extirpation, population decline, and homogenization of regional biodiversity are much more common. Human activities have frequently been the cause of invasive species circumventing their barriers, by introducing them for food and other purposes. Human activities therefore allow species to migrate to new areas (and thus become invasive) occurred on time scales much shorter than historically have been required for a species to extend its range.
What invaders are causing changes in the Great Lakes region?
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Answer: zebra mussels and the emerald ash borer


Problem: Roman women were present at most festivals and cult observances. Some rituals specifically required the presence of women, but their active participation was limited. As a rule women did not perform animal sacrifice, the central rite of most major public ceremonies. In addition to the public priesthood of the Vestals, some cult practices were reserved for women only. The rites of the Bona Dea excluded men entirely. Because women enter the public record less frequently than men, their religious practices are less known, and even family cults were headed by the paterfamilias. A host of deities, however, are associated with motherhood. Juno, Diana, Lucina, and specialized divine attendants presided over the life-threatening act of giving birth and the perils of caring for a baby at a time when the infant mortality rate was as high as 40 percent.
What was the amount of participation by women in religious observances?
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Answer: limited


Problem: Dogs bear their litters roughly 58 to 68 days after fertilization, with an average of 63 days, although the length of gestation can vary. An average litter consists of about six puppies, though this number may vary widely based on the breed of dog. In general, toy dogs produce from one to four puppies in each litter, while much larger breeds may average as many as twelve.
What is the average number of pups in a litter?
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Answer:
about six