Classification and Evolution Vocabulary التصنيف و التطور Classification and Evolution Vocabulary

Classification and Evolution Vocabulary, Overview Key Question: How do scientists categorize and name organisms? Initial Thoughts:

Early History Aristotle, a Greek philosopher, developed a system to classify living organisms over 2000 years ago. The science of classifying and naming organisms is called taxonomy. Aristotle began his system of taxonomy by dividing organisms into two groups called kingdoms. Plant Kingdom and Animal Kingdom Aristotle then divided these kingdoms into smaller groups. Animal Kingdom- Land, Water, Air

Early History Carolus Linnaeus, a Swedish physician created his own structure for classifying organisms. Body structure, size, shape, color, methods for obtaining food Binomial Nomenclature “Latin name” The first word of an animal’s scientific name is the genus. A genus is a group of different organisms that have similar characteristics. Together the genus name and the specific name make up the scientific name of the species. That’s a lot of names…

Canis familiaris Canis lupus Canis latrans

Modern Classification Classification is grouping ideas, information, or objects based on their similarities. Today, organisms are classified by the chemical makeup of the organism and its ancestors. Scientists find relationships among organisms by looking at similarities in genes, body structures, fossils, and embryos. All of these things help scientists determine an organisms phylogeny. The phylogeny of an organism is its evolutionary history.

Six-Kingdom System Organisms are classified into six kingdoms: Animal, Plant, Fungi, Protista, Eubacteria, Archaebacteria Organisms are placed into a kingdom based on characteristics like presence of a nucleus, single-celled or multi-cellular, ability to make food, and ability to move.

Six-Kingdom System

Prokaryotic vs Eukaryotic Organisms can be categorized as either prokaryotic or eukaryotic. Prokaryotes are uni-cellular organisms that have no true nucleus. Archaebacteria and Eubacteria Eukaryotes are multi-cellular organisms that contain a true nucleus. Protista, Fungi, Plant, Animal

Autotroph vs Heterotroph Organisms can also be categorized as either autotrophs or heterotrophs. Autotrophs are organisms that can “produce” their own food. Photosynthesis Heterotroph are organisms that “consume” other organisms for food.

Levels of Classification Kingdom --------------- Animalia Phylum --------------- Chordata Class --------------- Mammalia Order --------------- Carnivora Family --------------- Felidae Genus --------------- Panthera Species ------- Panthera leo

Common Names vs Scientific Names Erithacus rubecula Eopsaltria australis Turdus migratorius

Prairie Dogs Flying Fox Starfish Seahorse

Common Names vs Scientific Names Scientific names serve four basic functions: Help scientists avoid errors in communication Organisms with similar histories have similar names Give descriptive info about the species Allow information about organisms to be organized efficiently Scientists and nature enthusiasts can use a variety of tools to identify organisms. A dichotomous key is a detailed list of traits used to identify a specific organism.

Dichotomous Key

Evolution A species is a group of organisms whose members successfully reproduce among themselves. Over time, an organism’s hereditary features change in response to their environment. These changes can be observed through the study of evolution.

Evolution of the Horse

Charles Darwin Charles Darwin developed the theory of evolution in the mid-1800s. Darwin was the HMS Beagle’s naturalist responsible for recording information about all the plant and animal life observed during the journey. While on the Galapagos Islands, Darwin was puzzled by the number of finch species that were closely related, yet had different characteristics.

Natural Selection The factors Darwin identified that govern natural selection are: Organisms produce more offspring than can survive. Variations are found among individuals of a species. Some variations enable members of a population to survive and reproduce better than others. Over time, offspring of individuals with helpful variations make up more and more of a population. Variations are the occurrence of an inherited trait that makes an individual different from other members of the same species.

Natural Selection Darwin’s observations and experiments convinced him that individuals with traits most favorable for a specific environment survived and passed on these traits to their offspring. After extensive experiments all resulting in the same conclusions, this hypothesis eventually became the theory of evolution by natural selection. Natural Selection means that organisms with traits best suited for their environments are more likely to survive.

Adaptation Some variations can be harmful for an organism, but some can be beneficial. An adaptation is any variation that makes an organism better suited to its environment. These adaptations include a change in color, body shape, behavior, or chemical makeup.

Evidence for Evolution Scientists can study ancient organisms and their process of evolution by looking at fossils. Fossils are the remains of life from an earlier time. They give scientists an idea of what organisms existed and looked like millions of years ago. Fossil records give scientists convincing evidence that living things evolved, but there are other types of evidence to support the theory.

Evidence for Evolution Body parts that are similar in origin and structure are called homologous. Vestigial structures are also evidence for evolution. These structures are body parts that are reduced in size don’t serve a particular function.

Extinction By the time you are done reading this slide, one more plant or animal species may have joined the list of extinct species. Extinction is a natural event, the dying out of a species. The environment is constantly changing. Through the process of natural selection, those species that are unable to change or adapt are naturally removed. Evidence shows there have been at least four mass extinctions. Although many species die, many new species evolve to take advantage of the empty environment.

Analysis Questions Name the six kingdoms and give an example of each. Scientific names often describe a characteristic of the organism. What does Lathyrus odoratus tell you about the sweet pea? Using an example, explain how a new species of organism could evolve. How does an organism become extinct?

Summary/Reflection Write a paragraph explaining what you learned about classification and evolution. Create a mnemonic device to help you remember the levels of classification (Kingdom, Phylum, Class, Order, Family, Genus, Species). Kids have dreams but dreams cost money. Kilo-, hecto-, deca-, base, deci-, centi-, milli-.