Population density is loosely defined as the number of organisms in an area divided by the amount of area. Population density is typically measured in kilometers squared. High population density can cause increased competition for resources while low population density can cause problems with finding mates and inbreeding. (01:37)
Dispersion is the spreading of a population or organism away from its parents and happens when organisms are looking for additional resources or as an adaptation to environmental changes. Dispersion is influenced by various environmental factors such as temperature or terrain. Animals disperse by moving, while plants have seed dispersal.
Population growth is loosely defined as the change in the amount of individuals of a specials in an area over time. To find the growth rate of a population, we take the number of individuals moving into an area and subtract the number of individuals moving out of an area by taking the birth rate, adding the immigration rate and subtracting the death rate and emigration rate. Two types of population growth are exponential and logistic growth.
The atmosphere is the layer of air that surrounds the Earth and is comprised mainly of Nitrogen and Oxygen. The atmosphere also contains traces of gases like carbon dioxide, neon, helium, etc. There are 5 main layers of the atmosphere: the troposphere, the stratosphere, the mesosphere, the thermosphere and the exosphere. (04:10)
Japan - The 'Despised' Ainu People
An insightful report on racial discrimination in Japan. "A small boy denies his Ainu ancestry for fear of being bullied in a society where conformity is valued above all else. The Ainu people of the northern island of Hokkaido are despised by the rest of Japan. Different in appearance and language they have suffered more than a century of discrimination." (12:52)
Endangered species are defined as a species that is in immediate danger of going extinct. Species become endangered through a number of factors including disease, human activities and competition with other species. Examples of endangered species include the mountain gorilla and the black rhino. Another category is something called a threatened or vulnerable species. These are species that are in danger in the near-term. (03:01)
Behavioral ecology is the study of ecological and evolutionary causes of behavior in organisms. Behavior is influenced by genetics and the environment and should increase the reproductive fitness of a species. Common behaviors studied including things like learning, communication, foraging, reproductive strategies and social behaviors. (04:38)
Population ecology is the study of populations and their interactions with the environment. A population is a group of individuals of a species in a particular area. Population ecology studies things like population growth, selection strategies, population distribution, demographics and how populations evolve and adapt. (02:26)
"Our Little Ghost" by Louisa May Alcott (poetry reading)
Maybe this is a poem about a living child expressed in a somewhat macabre way, but on close examination that seems less likely. Louisa May Alcott is better known for her novel Little Women, published in 1865, one of the first novels of the movement called Literary Realism. When reality is harsh, literature and art tend to be idealised. Little Women is about a family of four sisters. Beth, the youngest, becomes ill and she actually dies. http://en.wikipedia.org/wiki/Louisa_May_Alcott http:/
Rescue operation in Sendai
Parts of Sendai burns as rescue workers search for survivors amidst the rubble and debris in Japan.
Protesters clash with police in Bahrain
Riot police face off against protesters near Pearl Roundabout as they attempt to block a main thoroughfare to the financial district.
Cleanup begins in Japan after quake
Residents in Japan are returning to their shattered neighborhoods and taking stock of the damage from Friday's devastating 9.0 magnitude earthquake
Libyan rebels face heavy air assault
Rebels are pushed back after being outgunned at Ras Lanuf and Uqaylah but fight to hold Ajdabiyah.
Clashes turn violent in Yemen
At least one person is dead and several injured as Yemen police open fire on protesters in Sanaa. Deborah Lutterbeck reports.
Prayers for Japan
The Pope calls on the faithful to pray for the victims of Japan's earthquake as citizens of Germany and Russia offer condolences. Deborah Lutterbeck reports
Bahrain erupts in violence
Police fire tear gas to disperse crowds in Bahrain as violence erupts. Deborah Lutterbeck reports
Widespread devastation in Japan
Rubble and debris litter the horizon in parts of Japan after an historic earthquake and tsunami.
China's super rich list surges
China tops Forbes billionaire list in Asia, but growing income gap may pose a worry ahead.
Evacuation centers fill up.
With fears of an impending nuclear reactor explosion, people are sprayed to remove radiation.
Japan's markets react to disaster
Japanese financial markets reopened after the most devastating natural disaster in the country's history, with eyes on its nuclear power facilities.