Hours after violent clashes between masses of protesters and police, Egyptians swarmed the polls early this week for the beginning rounds of parliamentary elections. They are the first elections since a prodemocracy uprising ousted longtime president Hosni Mubarak from office earlier this year. The poll stations have been remarkably peaceful, despite the simmering anger over the military’s extended role in running the government. In contrast, the Democratic Republic of Congo's presidential and legislative elections this week were beset by fraud, some observers say. In one town, rebel fighters attacked a polling place, killing at least five people and burning ballots. The voting was Congo's second since the end of the country's last war and the first organized by the government rather than the international community. -- Lloyd Young (30 photos total)

The Christian religious holiday may not arrive until December 25, but secular and commercial festivities have been in full swing for almost a month already. Increasingly the non-religious aspects of the holiday are celebrated even in countries without a strong Christian tradition. Gathered here are images of preparations from around the world as it begins to look a lot like Christmas. -- Lane Turner (42 photos total)

It's been just over a month since the capture and death of Libyan dictator Moammar Khadafy, ending his 42-year reign. Since then, the rebels have declared that the nation is liberated, installed a transitional government, and started the process of writing a constitution. Still, substantial problems remain. Pockets of fighting have erupted among rival tribes and some rebels have refused to give up their cache of weapons. Doctors continue to struggle to treat the wounded and sick, with a few of the most severely injured being sent to rehabilitation centers in Boston and elsewhere. Last weekend, Khadafy’s son, Seif, was captured and could face war crimes for his part in the conflict. -- Lloyd Young (EDITOR'S NOTE: We will not post a Big Picture on Friday, November 25, due to the Thanksgiving Holiday.) (40 photos total)

Protesters unhappy with the pace of change and the continued military rule in Egypt flooded Cairo's Tahrir Square over the weekend demanding civilian rule. Riot police responded with tear gas, beatings, and live ammunition, leaving at least 20 dead in continuing clashes. Egypt holds parliamentary elections next week, and demonstrators want presidential elections to be held shortly afterward. The ruling military has proposed to delay those elections until late 2012 or even 2013, angering Egyptians frustrated with the military's role in government. Collected here are images of the struggle over the weekend. -- Lane Turner (24 photos total)

There's still time! The deadline for entries for this year's National Geographic Photo Contest is November 30. Photographers of all skill levels (last year more than 16,000 images submitted by photographers from 130 countries) enter photographs in three categories: Nature, People and Places. The photographs are judged on creativity and photographic quality by a panel of experts. There is one first place winner in each category and a grand prize winner as well. The following is a selection of 54 entries from each of the 3 categories. The caption information is provided and written by the individual photographer. -- Paula Nelson (54 photos total)

In Guatemala City, a place called "The Mine" can deliver both a means of survival and a grisly death. Every day, dozens of residents salvage a living by scouring the massive dump for scrap metal. Facing the threat of mudslides, collapses, and disease, they can potentially earn twice the daily minimum wage. Associated Press photographer Rodrigo Abd documented their efforts. -- Lloyd Young (EDITOR'S NOTE: Our apologies, but due to an illness on our staff, we were unable to post a Big Picture on Monday.) (25 photos total)

According to projections by the United Nations, the world population has reached 7 billion and continues to grow rapidly.  While more people are living longer and healthier lives, gaps are widening between the rich and the poor in some nations and tens of millions of people are vulnerable to food and water shortages.  There is, of course, the issue of the impact of that sheer number on the environment, including pollution, waste disposal, use of natural resources and food production.  This post focuses on wheat and the effect of our numbers on the environment.  Wheat is the most important cereal in the world and along with rice and corn accounts for about 73 percent of all cereal production.  It isn't surprising that 7 billion people have a lasting impact on our world's natural resources and the environment in which we live. -- Paula Nelson (36 photos total)

With a per capita GDP of $900, Afghanistan ranks as one of the world's ten poorest countries. By any measure, challenges are numerous. Aid agencies observe an erosion of women's rights as foreign troops prepare to leave, the infant mortality rate is among the world's highest, and despite eradication efforts, 90 percent of the world's opium is still produced by Afghan farmers. Meanwhile, military fatalities approach 2800 since the war began in 2001. Civilians are afforded no such precision for their casualties, with varying estimates in the tens of thousands being the only accounting. Gathered here are images from the country made in October of the lives of women and children, daily life, and consequences of the conflict in Afghanistan and in the United States. -- Lane Turner (37 photos total)

The Hajj pilgrimage draws millions of Muslims from around the world every year to Mecca, the birthplace of the Prophet Muhammad, Islam's holiest place. Saudi Arabia expects to host perhaps three million people in a ritual journey that every able-bodied Muslim who can afford it must make at least once in their lifetime. It is the largest annual gathering of humanity anywhere. Timed to the Muslim lunar calendar, the Hajj is followed by the celebrations of the three-day festival of Eid al-Adha, or the Feast of Sacrifice, which symbolizes Abraham's willingness to sacrifice his son. Collected here are photographs of the Hajj in Mecca, Saudi Arabia, as well as images of preparations for the Hajj and Eid al-Adha in many other parts of the Muslim world. -- Lane Turner (42 photos total)

The growing population of the world, now estimated to be over 7 billion, marks a global milestone and presents obvious challenges for the planet.  There are extremely densely populated cities and sparsely populated countries.  China is the most populous country with India following closely behind. This post brings together some disparate illustrations of our world as it grows, including scenes from Mong Kok district in Hong Kong, which has the highest population density in the world, with 130,000 per one square kilometer. In Mongolia, the world's least densely populated country,  2.7 million people are spread across an area three times the size of France.  Then there's Out Skerries, a tiny outcropping of rocks off the east coast of Scotland where the population is just 65.  And doing what he can to contribute to that 7 billion global milestone is Ziona, the head of a religious sect called "Chana."  He has 39 wives, 94 children, and 33 grandchildren. The world is an interesting place. -- Paula Nelson  (41 photos total)

The 16th Pan American Games wrapped up with closing ceremonies this past weekend in Guadalajara, Mexico. Over 6,000 athletes from 42 nations in the Western Hemisphere competed for gold, silver, and bronze medals in many of the same events that will be seen during the Olympic Games next summer in London. Athletes were also vying for Olympic qualifying berths in many of the events. The 2015 edition of the games will be held in Toronto. -- Lloyd Young (35 photos total)