TAXONOMY

TAXONOMY NOTES, PT. 1

TAXONOMY Taxonomy = the science of grouping organisms on the basis of their similarities First taxonomic systems proposed by Greek philosopher Aristotle around 350 B.C. He divided living things into two groups: Animals & Plants He subdivided plants & animals on the basis of their size and structure Ex. Herbs, shrubs & trees were three major divisions of plants

TAXONOMY Aristotle’s system was used for more than 2000 years During the mid-1700’s, biologists set out to discover previously unknown forms of life As a result, thousands of newly discovered organisms were discovered yearly Using Aristotle’s system, biologists found it did not sufficiently describe the relationships between two organisms Ex. two species of cat with very different habitats and behavior would be forced into different groups

TAXONOMY System used to name these new organisms greatly varied This made communication between biologists very difficult Swedish botanist named Carolus Linnaeus developed new classification system He suggested that organisms with similar structures should be placed in the same taxonomic group and this group should be called a species

TAXONOMY Species = A biological group whose members resemble one another and interbreed to produce fertile offspring He suggested that similar species be grouped into a larger category called genus Ex. dogs, wolves and jackals are different species but are similar enough to be considered members of the same genus

COMMON NAME Most organisms are known by their common name Very confusing because one animal may end up with many names Ex. Mountain lion also known as puma, cougar, catamount or panther

COMMON NAME Two organisms may end up with the same name Ex. Dolphin (the bony fish, found in restaurants OR the mammal that people see at Sea World) Animals common names may be misleading Ex. starfish, silverfish and jellyfish are all very different and none of them are fish

SCIENTIFIC NAME To avoid such problems, the scientific name is used Scientific name is accepted by all scientists Linnaeus suggested that an organism’s scientific name be its genus name followed by its species name Known as binomial nomenclature (bi = two, nom = name) (nomenclature = system of naming things) Western lowland gorilla scientific name = Gorilla gorilla gorilla

SCIENTIFIC NAME Written in Latin in a very specific way Genus name begins with a capital letter Species name begins with a lower case letter Written in italics if typed or underlined if handwritten

SCIENTIFIC NAME Many scientific names are descriptive The red maple is Acer rubrum = red maple in Latin Sometimes scientists name organisms after a scientist he/she admires Genus Linnea, an herb in cold areas, named in honor of Linneaus Red maple = Acer rubrum Linnea borealis

SCIENTIFIC NAME Sometimes species names describe where an organism lives Darlingtonia californica = carnivorous cobra lily of California

TAXONOMY NOTES, PT. 2

TAXONOMY Theory of evolution has, since 1753, influenced classification Modern taxonomy still utilizes structural similarity as a basis but they also use chromosome structure, reproductive potential, biochemical similarities, and embryology to determine classification

CHROMOSOMAL MAKE-UP Scientists believed for a long time that humans were more closely related to gorillas than to chimpanzees based on our structures but found, when looking at chromosomes, that we are much more closely related to chimps than to gorillas.

REPRODUCTIVE POTENTIAL Scientists will cross closely related plants to see which ones will produce fertile offspring. Those that do are considered to be in the same species. Ex. Donkey + horse = mule (which is infertile ) Shows that they are NOT the same species

BIOCHEMICAL MAKE-UP Horseshoe crab was classified by its external appearance. When blood proteins were examined, it was found that these so-called crabs were more closely related to spiders. They have since been reclassified.

EMBRYOLOGY Scientists can look at the wing of a bat and the flipper of a whale and determine that they came from the same embryonic tissue and initially develop in the same manner. Meaning, bats and whales had a common ancestor and bats are more closely related to whales than they are to birds.

CLASSIFICATION Categories of classification—Largest to the smallest Kingdom (Kings) Phylum (Play) Class (Chess) Order (On) Family (Fancy) Genus (Girls) Species (Shoes)

CLASSIFICATION Ex. Humans Kingdom Animalia Phylum Chordata Class Mammalia Order Primates Family Hominidae Genus Homo Species sapiens Order Primates Kingdom Animalia Family Hominidae

CLASSIFICATION Ex. Killer whale Kingdom Animalia Phylum Chordata Class Mammalia Order Cetacea Family Delphinidae Genus Orcinus Species orca Class Mammalia Kingdom Animalia Order Cetacea Family Delphinidae

CLASSIFICATION Ex. Tiger Kingdom Animalia Phylum Chordata Class Mammalia Order Carnivora Family Felidae Genus Panthera Species tigris Ex. Lion Kingdom Animalia Phylum Chordata Class Mammalia Order Carnivora Family Felidae Genus Panthera Species leo

CLASSIFICATION Siberian Tiger Family Felidae Order Carnivora Female Lion

FIVE KINGDOMS Animalia = all multicellular animals Plantae = all multicellular plants Protista = most unicellular organisms Monera = cyanobacteria, bacteria, other organisms that lack nuclei Fungi = all fungi

MAJOR PHYLA Porifera—the sponges Colenterata/Cnidaria—Jellyfish, coral, anemones

MAJOR PHYLA Platyhelminthes—flat worms Nematoda—round worms

MAJOR PHYLA Annelida—segmented worms Mollusca—oysters, clams, octopus, squid

MAJOR PHYLA Arthropoda—insects, crabs, lobsters, shrimp Echinodermata—sea stars, sand dollars, sea urchins

MAJOR PHYLA Chordata—Birds, fish, mammals, reptiles, amphibians