Virtual Tour - Ice Age

The last Ice Age peaked about 20,000 years ago, after which the Earth again began to warm. Fossil evidence shows that by about 15,000 years ago, Ice Age people were roaming the plains and forests in North America, hunting enormous mammals with stone-pointed spears. Most of those animals were extinct by about 10,000 years ago. Did changes in climate or over-hunting by man cause the demise of Ice Age mammals? Scientists are still debating. Meanwhile, you can come face to face with the fossils of a long-tusked American mas todon, a towering giant ground sloth, a saber toothed cat poised to kill, a big horned bison, and dozens of other Ice Age animals.
NMNH Virtual Tour - Ice Age

Nationalities of China

The People's Republic of China officially describes itself as a multi-ethnic unitary state and as such officially recognizes 56 nationalities or Mínzú (民族), within China: the Han being the majority (>92%), and the remaining 55 nationalities being the national minorities. In addition to the 56 official nationalities, there are some Chinese who classify themselves as members of unrecognized nationalities. Also, foreign nationals who have become Chinese citizens form yet another separate group.

Technically, the term "nationality" is incorrect and misleading, rather "ethnicity" is correct, in that none of these groups have their own nation, and thus self-determination. The direct translation of (民族) would be "peoples".

In general, the system of 56 nationalities is applied only within mainland China although Taiwanese aborigines are classified as one of the 56 nationalities - Gaoshan. Hong Kong and Macau do not use this ethnic classification system, and figures by the PRC government do not include Hong Kong and Macau.

The official PRC point of view is that all of these above nationalities are part of a broader "civil ethnicity" known as Zhonghua Minzu.

Nationalities of China

Life Cycle with AIDS

The HIV virus’s life cycle begins as it is born in a host cell. The virus exits the cell through its cell membrane, and searches for a new T-cell to infect. The virus can identify the cell it wishes to find, the CD4+ T-cell, because they have CD4 molecules on their surface. Once the virus reaches a victim, it attaches itself to the CD4 molecules that make up its surface, and the virus’s outer envelope merges with the cells and becomes one.

All About AIDS

Pandemic fears loom over flu season

Pandemic fears loom over flu season

Concerns over the seasonal flu, which sickens millions of people each winter, have taken a back seat this year to fears of the bird flu and the horrifying potential that it could evolve into a worldwide pandemic.

The seasonal flu kills about 36,000 people every year and sends 200,000 to the hospital, according to the U.S. Centers for Disease Control and Prevention. But most of those cases involve people who are elderly, very young or weakened by another condition.

Pandemic fears loom over flu season

NATURE: The Elephants of Africa

Africa. Sprawled across this continent are vast savannahs, seemingly endless deserts, and impenetrable rain forests. Each region is dotted with a unique array of wild animals, from elusive leopards to the delicate, gazelle-like bongo. However, roaming throughout every African ecosystem is one constant: the elephant, which makes its home in every type of landscape. As filmmaker and elephant expert Cynthia Moss shows in THE ELEPHANTS OF AFRICA, elephants are all over the continent. While the celebrated savannah elephants of Kenya and other parts of East Africa draw thousands of tourists to the local parks, this group makes up only a portion of Africa's elephants.

NATURE: The Elephants of Africa

NATURE Lemur

Do you know it--Lemur?

Lemurs are small primates and although we look nothing alike, lemurs and humans are related! Lemurs come as small as a mouse and as large as a housecat. There are 50 species of lemurs and 17 of them are on the endangered species list. Lemurs are most recognizable for their big, bushy tails that they wave to each other in order to communicate and to help them keep their balance when leaping from tree to tree. One type of lemur, the sifaka, is famous for its vertical leaps; it is able to leap 30 feet in one bound.

NATURE. Critter Guide. Lemur. | PBS

Human Genetics and Medical Research

What Are Genes?

Chromosomes contain the recipe for making a living thing. They are found in almost every cell’s nucleus and are made from strands of DNA (deoxyribonucleic acid). Segments of DNA called "genes" are the ingredients. Each gene adds a specific protein to the recipe. Proteins build, regulate and maintain your body. For instance, they build bones, enable muscles to move, control digestion, and keep your heart beating.

A Revolution in Progress