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Linnaeus And Biological Classification . Chapter 5 Pages 103-105. Grouping. Placing organisms into domains and their subdivisions is a classification scheme that indicates the evolutionary relationships of the organisms being studied.
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Linnaeus And Biological Classification Chapter 5 Pages 103-105
Grouping • Placing organisms into domains and their subdivisions is a classification scheme that indicates the evolutionary relationships of the organisms being studied. • Helpful to have a universal system to group these organisms
Taxonomy • Biologists needed a system of naming things that everyone would recognize around the world. • The science which deals with describing, classifying, and naming organisms.
Linnaeus • Karl van Linne (Carolus Linnaeus) • Swedish botanist in the mid 1700’s • In 1750 developed a method of a two word naming system • Binomial Nomenclature • A naming system that uses two words to identify an organism
Binomial Nomenclature • The first word of a proper scientific name is the genus • These organisms shared certain traits in the same genus • Always capitalized • The second part of the name is the specific epithet and describes a specific species • Always lowercased
Grouping • Grouped organisms into genera on the basis of similar morphology • Organisms were then grouped into larger categories called classes and orders.
Taxonomic Categories • Used to show complex evolutionary relationships among related organisms. • Domain • Kingdom • Phylum • Class • Order • Family • Genus • Species
During Linnaeus’s time, and until the 1960’s, biologists grouping all living organisms into one of two kingdoms: Plantae Animalia Animalia- contained the organisms that fed on other organisms (heterotrophs) and that were capable of independent movement All other organisms (autotrophs and saprotrophs, or decomposers) were classified in the kingdom Plantae Early Grouping
Invention • With the invention of the electron microscope and the accumulation of more information from biologist things began to change • This led to the Kingdoms we have today • Fungi • Plantae • Animalia • Protista • Eubacteria • Archeabacteria
Domains • During the 1980’s biologists began to recognize that not all prokaryotes were closely related. • Three Domains • Eubacteria • Archaea • Eukaryea
Fungi • Eukaryotic • Not capable of photosynthesis and whose cell walls contain the polysaccharide chitin • Unicellular and multi-cellular • Yeast, mold, mushrooms
Plantae • Plants • Cells with cell walls • Contain polysaccharide cellulose • Multi-cellular and capable of photosynthesis
Animalia • Animals • Are all multi-cellular • Cells lack cell walls and they are ingestive heterotrophs • Rely on other organisms for food, which they take into their bodies to digest.
Protista • Protists • Eukaryotic • “mis-fits” do not fit the definition of a plant animal or fungi. • Algae, protozoans, and slime molds. • Most are unicellular • Some multi-cellular • May or may not have cell walls
Cont. • Nutritionally they can be autotrophs, heterotrophs, saprotrophs or a combination of several. • Many scientists believe this grouping is artificial
Classifying marine mammals • Marine mammals have four main characteristics • Warm-blooded • Live birth • Mammary glands • Hair • They also have a large well developed brain
Evolutionary history of Marine Mammals • Has a fetus the mammal has four limbs, a pelvis and a tail • The fore-limbs become flippers that have great similarity to land mammal limbs • The nostril located to the front of the fetus shifts to the top of the head to form a blow hole.
Whale Hunting • In the past whales have almost gone extinct due to being hunted for their oil and blubber • This is no longer necessary due to our advanced technology. • However whales and many marine mammals are still hunted due to lack of law enforcement in many areas
Save Marine Life • In 1972 the Marine Mammals Protection Act was designed to stop needless hunting of these beautiful creatures.
What divides the Cetaceans into categories. • Cetaceans are divided on the basis of structures in the mouth • The toothed whales belong to Odontoceti. • The baleen whales are toothless and have strainers suspended from their upper jaws to collect plankton. They belong to Mysticeti.
Whale? Shark? Fish? • The whale has a horizontal tail fluke whereas sharks and fish have a vertical tail. • In many species the markings on their body can be as different has a humans fingerprint, allowing scientists to better identify them.
Dolphins vs. Whales • The dolphins as a sub-group of toothed whales all have a large dorsal fin. The killer whale is the larges dolphin.
Pinnipeds vs. Cetaceans • Both marine mammals. • Pinnipeds are often found on land for breeding, raising young and resting. • Have hind limbs • Dense fur. • Lack tail fluke
Greenpeace • Greenpeace is an international, non-profit organization dedicated to: “preserving the earth and all the life it supports;… and halting the needless slaughter of whales, dolphins, seals and other endangered animal.” • In 1986 they contributed to the law that now makes hunting whales illegal • The goal now is to close loop-holes to make “scientific whaling” illegal