about Kingdoms and sorting things out

The Universe is full of many things. Some are living. Some are non-living. Some are mysterious and we don't know if they are actually living or not, or may appear to be alive, but in a different form than recognized life. For instance, a virus is not considered by many to be a life form per se, because it does not contain certain things which are deemed necessary to be so considered. However, it has the ability to mutate and change. We humans have so much more to learn in the future. The more we learn, the more we discover we don't know and hence recognize we have so much more to learn.


This is a perplexing question, which has been pondered by many for centuries. Gradually, over many years, but more rapidly in just the past half century or so, Scientists are finding life in many places where life was never known to exist or thought to be able to exist. Places like under the Arctic and Antarctic ice caps; like in steaming hot hydrothermal pools like in Yellowstone National Park; and in hydrothermal vents, some called "black smokers" in the deepest ocean trenches. Life abounds around these "black smokers" and other hydrothermal vents, sustained not by photosynthesis as in things which grow in sunlight, but feeding upon hydrogen sulfide for energy.

Therefore, not only does life exist in a lot of places which were previously deemed unsuitable for life, but it leaves much more likely that life can exist other places in the Universe, other than Earth. Scientists involved in astronomy are ever more able to delve into the Universe and report seeing planets circling other suns, which appear to be in temperature zones and potential of elements present, which would allow life. No doubt in the near future, astronomers and other scientists will learn ever more about out Universe and its potential for life.

Who or what created life? Certainly the answer has to be that "it didn't just happen from nothing". Therefore, some mysterious force, which some of us call God, had to have started the process.

A discussion and some points considered to be determinative by the the National Earth Science Teachers Association (NESTA) [copyright 2010] appear on the website "Windows to the Universe" located at http://windows2universe.org/.

"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".

The above information quote is subject to provisions of Creative Commons as shown at http://creativecommons.org/licenses/by-sa/3.0/

PMNS will be setting up another page to discuss things which appear to be alive, but which don't fit all of the above six points, and hence aren't considered alive, yet do some things which make it appear they are alive or possibly possess a third status between live things and things which are not alive.


Many years ago, living things were lumped into two Kingdoms. Animal and Plant. That was it.

Over the years, the number of purported Kingdoms of living things has changed over and over.

Aristotle (384-322 BC) classified animal species in his work the History of Animals. His pupil, Theophrastus (circa 371-287 BC) prepared his own work about the same time, the History of Plants.

Carolus Linnaeus (1707-1778) worked on this matter, as he did on a number of other important natural science areas. Linnaeus laid out modern nomenclature of biological entities, i.e. living things. He also recognized only two kingdoms of living things, which he designated as Regnum Animale (i.e. the Animal Kingdom) and Regnum Vegetabile (i.e. the Plant Kingdom). However, Linnaeus also designated a third kingdom of non-living things which he called Regnum Lapideum (Lapidary, i.e. minerals). He divided these kingdoms into sub units called classes, later grouped into phyla for animals and divisions for plants.

Until about 1674 single cell life was unknown. That year Antonie van Leeuwenhoek delivered to the Royal Society of London documentation of his first microscopic observations of single celled life. van Leeuwenhoek was called the "father of microscopy". These single cell creatures were divided into the classical two kingdoms, as plants and animals. Until van Leeuwenhoek, single cell creatures were unknown.

By the middle of the Nineteenth Century (mid 1800s) having only two kingdoms was realized as blurring the lines between plants and animals as not everything seemed to fit comfortably in only these two categories. A third Kingdom was set up called protoctista. The distinction was that if the life was unicellular, i.e. one celled, then it was protoctista. If it was multicellular, then it went into the traditional plant or animal kingdom. This decision followed previous proposals by Richard Owen and John Hogg. The actual proposal for the third Kingdom came from Ernst Haeckel, after he had revised several concepts first.

Some information, courtesy of Wikipedia, the free encyclopedia retrieved from http://en.wikipedia.org/wiki/Kingdom_(biology).

The order shown by the National Earth Science Teachers Association (NESTA) copyrighted 2010 shows these five kingdoms (we show them in alphabetical order):
Kingdom Animalia
Kingdom Fungi
Kingdom Monera
Kingdom Plantae
Kingdom Protista

There is a great deal of disagreement on the number of Kingdoms and what should go into them, other than the Animal and Plant Kingdoms.