Shop Windows to the Universe

Please help support Windows to the Universe, and our activities to help Earth and space science teachers, with a tax-exempt donation today!

Exploratour - Life on Earth

Short-eared owl
Click on image for full size
Corel Photography

This tour is a detailed look at life on Earth, and what we know about how it came to be. To proceed with the tour, just click on the forward indicator in the "football" at the top right portion of this page.

If you had to explain to someone what "life" is, what would you tell them? Do all living things move? Do they eat and breathe? Even though we all seem to know what is meant by saying something is "alive", it's not very easy to describe what "life" is.

The study of life is called "biology" and the people who study it are "biologists". They even have a tough time describing what life is! But after many years of studying living things, from the mold on your old tuna sandwich to monkeys in the rainforest, biologists have determined that all living things, do share some things in common:

1) Living things need energy
2) Living things grow and develop
3) Living things respond to their surroundings
4) Living things reproduce
5) Living things reproduce and pass their traits onto their offspring
6) Over time, living things evolve (change slowly) in response to their environment

We will discuss some of these things in the pages that follow.

This is page 1 of 20

Shop Windows to the Universe Science Store!

Our online store includes books on science education, classroom activities in The Earth Scientist, mineral and fossil specimens, and educational games!

You might also be interested in:

Science, Evolution, and Creationism

How did life evolve on Earth? The answer to this question can help us understand our past and prepare for our future. Although evolution provides credible and reliable answers, polls show that many people turn away from science, seeking other explanations with which they are more comfortable....more

Exploratour - Life in the Solar System

Life as we know it on earth requires a certain environment to survive. Life on Earth can survive in temperatures of -130 degrees to +130 degrees. Even so, there are creatures on earth which seem to be...more

Exploratour - Life in the Solar System

Believe it or not, many scientists believe that life may have begun on these distant, solar system traveling objects. Out in their distant home, the Oort Cloud, comets are exposed to the kind of cosmic...more

Exploratour - Life in the Solar System

In spite of the fact that Mars has an atmosphere, the environment of Mars seems unfriendly toward life as we know it on earth. Mars is small, so there is not much gravity. For this reason, much of the...more

Exploratour - Life on Mars?

In spite of Mars' similarity to Earth in size and closeness to the sun, the environment of Mars seems unfriendly toward life as we know it on Earth. Mars is small, so there is not much gravity. For this...more

Exploratour: NASA's Exploration for Life

Believe it or not, many scientists believe that life may have begun on these distant, solar system traveling objects. Out in their distant home, the Oort Cloud, comets are exposed to the energy needed...more

Exploratour - Life in the Solar System

Earth is teeming with life. The table below gives a brief overview of life on Earth, catagorized the way biologists catagorize life on Earth. The Animal Kingdom mammals elephants, rodents, etc arthropods...more

Exploratour - The Archean Age

In the 1950's, biochemists Stanley Miller and Harold Urey, conducted an experiment which demonstrated that some of the basic elements of life, including amino acids, could be formed spontaneously by simulating...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF