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Biodiversity Organizing and Classifying Life on Earth

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microbes

Biodiversity Outcomes

  • Explain why it is important to classify organisms
  • Describe the contributions of Carl Linnaeus.
  • List the three Domains of life and four Kingdoms in Domain Eukaryota.
New species are still being discovered; identification is key in discerning between organisms.
Both of the species below are in the \”wild carrot\” family, but one is poisonous.  Identification would have been critical to early humans to avoid potentially toxic or otherwise dangerous species.
Queen Anne\'s Lace

Queen Anne\'s Lace

Poison Hemlock

Poison Hemlock

herring

Once trade routes were established, it was important that organisms be properly named.  The problem was that many organisms were getting the same names, even though they actually had significant differences.

A \”herring\” fish could mean a species that was tasty or something that was inedible.

Since there are 10+ million species on Earth, simply identifying is not enough.  There needs to be some way of discussing relationships between species and that is where classification comes in.
linnauesflowerclock

The \”Father of Taxonomy,\” the science of classification, is Carl Linnaeus, introduced last week in the Flowers activity. 

Linnaeus, among many other things, developed a \”flower clock\” that could be used to indicate the time of day by which flower was open.

Carl Linnaeus also developed a scientific naming (nomenclature) system that could be used to identify an individual species and indicate how it related to other identified species.  This system is still used with some modifications.

linaeus
Biodiversity
One of the groups Linnaeus classified was the Corvidae.
 
The Corvids include the crows, ravens, jays, and magpies.
All organisms were classified as either plants or animals.  Then these two groups were broken into smaller and smaller groups until you were left with a single species.  

 

So a bird similar to the American Crow, the Western scrub jay, is classified in the same Kingdom, Phylum, Class, Order, and Family.  It has a different Genus and species (Aphelocoma californica).

crowclass
Microscope technology and genetic analysis revealed that we needed to add microscopic organisms to Linnaeus\’ classification system.  It turns out not everything was simply a plant or an animal.
domains 2

There are now three Domains: Bacteria, Archaea, and Eukaryota (also called Eukarya) that are ranked higer than Kingdom.

There are four Kingdoms in Domain Eukaryota: Protists, Fungi, Plants, and Animals.

Three Domains of Life

Microscopic single-celled organisms that were the earliest forms of life on earth and gave rise to archaeans and eukaryotes.

Bacteria

Microscopic single-celled organisms that were the earliest forms of life on earth and gave rise to archaeans and eukaryotes.
Microscopic single-celled organisms that arose from the bacteria and can be found in extreme environments like salt lakes and hot springs.

Archaea

Microscopic single-celled organisms that arose from the bacteria and can be found in extreme environments like salt lakes and hot springs.
Single-celled to multi-cellular organisms that have more complex cellular structures than bacteria or archaea.

Eukaryota

Single-celled to multi-cellular organisms that have more complex cellular structures than bacteria or archaea.

Four Kingdoms of Domain Eukaryota

Primarily microscopic single-celled organisms that have complex internal structures. Most are found in water and include amoeba and algae.

Protists

Primarily microscopic single-celled organisms that have complex internal structures. Most are found in water and include amoeba and algae.
Decomposers that primarily obtain energy and nutrients from the remains of other organisms. Includes mushroom-producing species and yeast.

Fungi

Decomposers that primarily obtain energy and nutrients from the remains of other organisms. Includes mushroom-producing species and yeast.
Multi-cellular organisms that can convert sunlight energy to sugar energy. Includes moss, grasses, and trees.

Plants

Multi-cellular organisms that can convert sunlight energy to sugar energy. Includes moss, grasses, and trees.
Multi-cellular organisms that need to consume other organisms to survive and typically move to obtain that food. Includes sponges, beetles, and humans.

Animals

Multi-cellular organisms that need to consume other organisms to survive and typically move to obtain that food. Includes sponges, beetles, and humans.
foxclassification

Most of Linnaeus\’ original hierarchy of classification is still intact, with modifications made as new complexity is revealed.

biodiversity 1

Check your knowledge.  Can you:

  • explain why it is important to classify organisms?
  • describe the contributions of Carl Linnaeus?
  • list the three Domains of life, and four Kingdoms in Domain Eukaryota?

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