In 1862, Congress passed and President Lincoln signed the Pacific Railroad Bill, …
In 1862, Congress passed and President Lincoln signed the Pacific Railroad Bill, which granted public land and funds to build a transcontinental railroad. The Central Pacific Railroad would lay tracks from California heading east, and the Union Pacific Railroad would lay tracks from the Missouri River west. The photograph taken in Placer County, "Grading the Central Pacific Railroad," shows some of the construction. Work on the railroad was physically difficult and at times dangerous, and attracting workers was a challenge. The majority of the Central Pacific's laborers were Chinese. A Chinese worker is shown in the image "Heading (top cut) of East Portal, Tunnel No. 8." Both railroad companies actively recruited Chinese laborers because they were regarded as hard workers and were willing to accept a lower wage than white workers, mostly Irish immigrants. As construction progressed, the Central Pacific and the Union Pacific competed to see which could lay the most track each day. A photograph of a sign near Promontory Park, Utah, commemorates the day that Central Pacific crews laid an unprecedented 10 miles of track. The meeting of the two sets of tracks ? the "gold spike" ceremony ? took place on May 10, 1869. Several photographs and drawings depict this historic moment. Now the country was connected as never before: a journey between San Francisco and New York that previously took up to six months now took only days. The photograph "High Bridge in Loop," from Views from a Trip to California, shows a train passing quickly through a mountain pass. The transcontinental railroad allowed people to travel more, farther, and in pleasant conditions, as reflected in the photograph "Commissary Car, 'Elkhorn Club.'" The photograph "Knights of Pythias at the Santa Fe Railway Station, Anaheim" shows an example of the popularity of trains. Even as the transcontinental railroad brought the new country together, it brought change to the world of Native Americans. The tracks ran through a number of tribal territories, bringing into conflict cultures that held very different views of the land and how it might be used and lived on. The painting The First Train, by Herbert Schuyler, depicts three Indians pointing past their encampment at a train in the far distance. The railroad also brought an increasing number of European Americans west. One consequence of this influx was the depletion of the buffalo herds, a major food source for Plains Indians. European Americans would often shoot buffalo for sport from the train; by 1880, the buffalo were mostly gone and Plains Indians had been gathered onto reservations. Millions of acres of open grassland were being settled by the people moving west. Eventually, much of this land became the farmland that fed a growing nation. The transcontinental railroad opened up the West to the rest of the country, even if they never made the trip themselves. A Currier & Ives hand-colored lithograph depicts a train running along the Truckee River in Northern California. The San Francisco publishing firm of Lawrence & Houseworth hired photographers and published photographic tourist catalogs containing views of the West, which they sold commercially. The railroad took hold in popular culture, as shown by sheet music for the song "New Express Galop [sic]." There was even a railroad board game illustrating "Railroads Between New York and San Francisco, California, with Scenes on the Way."
This list of conceptual understandings regarding evolution are aligned across grade levels …
This list of conceptual understandings regarding evolution are aligned across grade levels to help instructors identify age-appropriate learning goals for their students and understand how concepts taught at one grade level lay the groundwork for more sophisticated concepts later on. The Framework is divided into five strands: History of life; Evidence of evolution; Mechanisms of evolution; Nature of science; and Studying evolution
Extinction is a fact of modern life. Humanity's relentless encroachment on the …
Extinction is a fact of modern life. Humanity's relentless encroachment on the wilderness has marred the diversity of life with conspicuous gaps where the Tasmanian tiger, the Passenger Pigeon, the Ivory-billed Woodpecker, and countless others used to be. As these extinctions accumulate, the Earth inches closer and closer to its sixth mass extinction. We are all too familiar with the concept of mass extinction - a disaster strikes and sets off a chain of events that result in a massive die-off. But you may not have considered what comes next: what happens to surviving species in the wake of a massive extinction event? Recent research suggests that mass extinctions shake up life on Earth in surprising ways.
In the next few months, college students across the country will be …
In the next few months, college students across the country will be offered the chance to save a life by swabbing cells from the insides of their cheeks and registering as a potential marrow donor with Be The Match The Give A Spit About Cancer campaign, which launched in October, helps college students organize marrow donor registry drives. The cells collected in these drives are used to figure out who might be able to donate marrow or blood stem cells to a patient with a life-threatening disease like leukemia. While ethnicity is irrelevant to most medical procedures, marrow and blood stem cell transplants are an exception to this rule.
This month, the World Health Organization announced that tuberculosis cases are on …
This month, the World Health Organization announced that tuberculosis cases are on the decline for the first time in at least 20 years. We seem finally to be winning what has been a very long battle. Tuberculosis bacteria have been attacking us since modern humans began to migrate out of Africa around 40,000 years ago. If you enjoy classic literature, you'll be familiar with the cough, fever, and weight loss of consumption (the old-fashioned term for tuberculosis), which used to be a near certain death sentence. That changed when the aminoglycoside antibiotic streptomycin was discovered in 1943.
Though we often think of evolution as occurring at a snail's pace, …
Though we often think of evolution as occurring at a snail's pace, one fish species is highlighting just how quickly evolution occurs in the right circumstances. Between 1947 and 1976, General Electric released more than a million pounds of PCBs into the Hudson River. PCBs can kill fish and seabirds and have been linked to cancer and other serious health problems in humans. PCBs were banned in 1979, but the toxins have remained at high levels in the Hudson because they settle into the sediments on the bottom of the river and don't break down. Now, scientists have discovered that, over the past 60 years, one bottom-feeding fish species, the Atlantic tomcod, has evolved resistance to PCBs.
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