Essential Question: How do biologists classify organisms?

Transcription

1 Topic: The Biological Classification System Essential Question: How do biologists classify organisms? In 2008, Usain Bolt set the world record for the 100 meters with one shoelace undone. 3/25/16 Taxonomy

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3 Why would biologists need to classify living things? Think of three reasons. Share your reasons with your neighbor.

4 Classification of living things To be useful, it helps to create a system just like you did with the seashells. Let s see how well your systems work.

5 Get a set of shells and you will be given a classification by another pair. Pick out a few shells and try using the system made by someone else. Find something about the system that you think works well write a sentence explaining this on the paper itself. Write down one thing you would change and/or improve and why. Sign it and return to original creators.

6 Essential Question: How do you group organisms in an organized way? On Wednesday s page, under the picture of your system, answer the essential question. Put an outline around it to make it easy to find later.

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8 * Important note- the system of classification is man-made and is constantly being changed by taxonomists as new organisms are found or new information is learned (such as similarities in DNA). But the system is based on real relationships.

9 The First Taxonomist The first scientist to develop a system of classification was Aristotle in the fourth century B.C. He divided animals into three groups:

10 Those that fly

11 Those that swim

12 Those that walk, crawl, or run

13 Then he divided these groups in to smaller groups.

14 Then he divided these groups in to smaller groups.

15 Early classification systems In the 1750 s, a Swedish scientist named Carolus Linnaeus sought to improve Aristotle's system. He placed organisms in groups based on observable characteristics. He devised a naming system for organisms so people could not confuse different organisms.

16 The system is called Binomial Nomenclature Each organism is given a twopart name. The first part is the genus a grouping of similar, closely related organisms. For example, the cat family is the genus Felis.

17 Pumas, ocelots, and house cats are all in the genus Felis and share characteristics such as retractable claws and hunting behaviors.

18 The second part of the name is the species name. A species is a group of similar organisms that can mate and produce fertile offspring. The species name often describes a distinctive feature of the organism. This organism is Felis concolor.

19 Felis concolor Genus name (first) species name Underlined (or in italics) Genus capitalized species not capitalized

20 Using Scientific Names When you identify any organism, you must use both the genus and the species names together. Thus, Homo sapiens (humans), not just sapiens.

21 Felis domesticus Felis concolor

22 Today, Classification takes evolution into account. Species with more similar evolutionary history are classified more closely together. How do we know? Much of the information comes from genetics.

23 Levels of Classification Taxonomists group organisms into seven basic levels from broad, general groups down to very specific groups. The more levels two organisms share, the more similar they are.

24 Kingdom Phylum Class Order Family Genus Species

25 Kingdom More types of living things Phylum Class Order Family Genus Species Fewer types of living things

26 Kingdom

27 Phylum

28 Class

29 Order

30 Family

31 Genus

32 Species

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34 Kingdom Phylum Class Order Family Genus Species

35 Kings Play Chess On Friday Generally Speaking

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38 Classification levels are still changing. Levels