What is Life?



Short-eared owl
Click on image for full size (96K JPEG)
Image courtesy of Corel Photography.
What is life? Does this seem like a strange question to you? Well, let's think about it. 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. It's almost as hard as describing where life came from.

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



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Learn about ocean life!

What is Life?



Short-eared owl
Click on image for full size (96K JPEG)
Image courtesy of Corel Photography.
What is life? Does this sound like a strange question to you? Of course we all know what is meant by the word "life", but how would you define it?

Do all living things move? Do they all 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. It's almost as hard as describing where life came from.

Even the biologists (people who study life) 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 to take in energy
2) Living things get rid of waste
3) Living things grow and develop
4) Living things respond to their environment
5) Living things reproduce and pass their traits onto their offspring
6) Over time, living things evolve (change slowly) in response to their environment

Therefore, in order for something to be considered to "have life" as we know it, it must possess these characteristics.

Image archive

Learn about ocean life!

What is Life?



Short-eared owl
Click on image for full size (96K JPEG)
Image courtesy of Corel Photography.
What is life? If this strikes you as an odd question, consider it for a moment. (It's almost as hard as describing the origin of life). Of course we all have an intuitive sense of what life is, but how would you actually define it? Given the incredible diversity of living things, from the mold on your old tuna sandwich to monkeys in the rainforest, how could one word encompass all that "life" represents?

Even biologists have a difficult time defining the very concept they study. However, given our knowledge of the life forms present on Earth, it is recognized that all living things do share a set of characteristics in common:

1) Living things take in and use energy
2) Living things eliminate waste products
3) Living things grow and develop
4) Living things respond to their environment
5) Living things reproduce
6) Living things show variation based on heredity
7) Over time, living things evolve (change slowly) in response to their environment.

Therefore, in order for something to be considered to be "alive" or to "have life" as we know it, it must possess these characteristics.

Image archive

Learn about ocean life!



Last modified April 29, 2004 by Lisa Gardiner.
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