Autotrophs capture the light energy from sunlightand convert it to chemical energy they use for food.Heterotrophs must get energy by eating autotrophs or other heterotrophs. •Carnivores •Herbivores •Omnivores Decomposers are heterotrophs that recycle deadorganisms by breaking them down.
• Taxonomy is the science of groupingand naming organisms. Groups organisms based on similarities• Classification the grouping ofinformation or objects based onsimilarities.
•We only know about a fraction of the organisms thatexist or have existed on Earth.•Taxonomists give a unique scientific name to eachspecies they know about, whether it’s alive today orextinct.•The scientific name comes from one of two “dead”languages – Latin or ancient Greek.•Why use a dead language?
•There are at least 50 common names for the cat shown on the previous slides.•Common names vary according to region.•Soooo……why use a scientific name? There are about 1.5 million species already named Scientists estimate between 2 and 100 million species that haven’t been discovered yet
Binomial Nomenclature •developed by Carolus Linnaeus •a two-name system for writing scientific names. •The genus name is written first (always Capitalized). •The species name is written second (never capitalized). •Both words are italicized if typed or underlined if hand written. •Example: Felis concolor or F. concolor 1. Which is the genus? The species?
The major classification levels from mostgeneral to most specific (several of these havesubdivisions)•Linnaeus grouped organisms based onphysical similarities•Today, organisms are grouped based onevolutionary characteristicsA group at any level is a taxon.
Categories within Kingdoms Kingdoms are divided into groups called phyla Phyla are subdivided into classes Classes are subdivided into orders Orders are subdivided into families Families are divided into genera Genera contain closely related species Species is uniqueRemember: King Philip came over for George’s sword.
The Six Kingdoms and Domains number of energy cell type examples cellsArchaebacteria unicellular some autotrophic, prokaryotic “extremophiles” most chemotrophicEubacteria unicellular autotrophic and heterotrophic prokaryotic bacteria, E. coliFungae most heterotrophic eukaryotic mushrooms, yeast multicellularPlantae multicellular autotrophic eukaryotic trees, grassAnimalia multicellular heterotrophic eukaryotic humans, insects, wormsProtista multicellular heterotrophic or autotrophic eukaryotic amoeba, paramecium, algae
The Dichotomous Key• A key is a device for easily and quickly identifying an unknown organism.• The dichotomous key is the most widely used typein biological sciences.• The user is presented with a sequence of choicesbetween two statements, couplets, based oncharacteristics of the organism. By always makingthe correct choice, the name of the organism will berevealed.
Modern TaxonomyPhylogeny, the evolutionary history of an organism, isthe cornerstone of a branch of biology called systematictaxonomy.Systematics, as systematic taxonomy is commonly called,is the study of the evolution of biological diversity.
A phylogenetic tree is a family treethat shows a hypothesis about theevolutionary relationships thought toexist among groups of organisms. Itdoes not show the actual evolutionaryhistory of organisms.
Phylogenetic trees are usually based on acombination of these lines of evidence: Fossil record Morphology-deals with physical structures and organs (like arms) Embryological patterns of development Chromosomes and DNA
Cladistics - is a relatively new systemof phylogenetics classification thatuses shared derived characters toestablish evolutionary relationships.A derived character is a feature thatapparently evolved only within thegroup under consideration.
A phylogenetic tree based on acladistic analysis is called acladogram.What derived character is shared byall the animals on the cladogram onthe next slide?