What are biological species? Easy question? Homo sapiens = Canis familaris ? Easily distinguished, but technical literature less clear Biologists have dozens of definitions Not fringe accounts, but prominent with current biological literature Play NB role in/out Biology In – fundamental units of classification Out – debates over environmental laws etc.

Systematics The study of the diversity of organism characteristics, how they relate evolutionarily, establishing their phylogeny regardless of there phenetics.

Phylogeny Origin and evolution of a set of organisms A major task of systematics is to determine the ancestral relationships among known species. Phylogenetics - study of evolutionary relatedness among various groups of organisms (e.g., species, populations). treats a species as a group of lineage-connected individuals over time. classifying groups of organisms according to degree of evolutionary relatedness. characters - nucleotide or amino acid sequences.

Phenetics Attempt to classify organisms based on overall similarity, usually in morphology or other observable traits, regardless of their phylogeny or evolutionary relation.

Biological Classification Biologists group and categorize species of organisms NB extinct and living ! Modern classification has its root in the work of Carolus Linnaeus, who grouped species according to shared physical characteristics. Improve - Common descent, Molecular systematics. Scientific classification belongs to the science of taxonomy or biological systematics.

Common Descent A theory of universal common descent based on evolutionary principles was proposed by Charles Darwin This theory is now generally accepted by biologists, and the last universal common ancestor is believed to have appeared about 3.5 billion years ago. The theory of universal common descent proposes that all organisms on Earth are descended from a common ancestor or ancestral gene pool.

Molecular Systematics The evolutionary relationships of organisms are studied using their DNA, RNA and protein sequences These techniques help in objectively determining the importance of characters or markers and in evaluating evolutionary hypotheses. Molecular systematics has introduced major revisions in many groups of organisms.

Taxon Grouping of organisms (named or unnamed). Once named, a taxon will usually have a rank and can be placed at a particular level in a hierarchy.

Carl Linnaeus Swedish botanist, physician and zoologist laid foundations for the modern scheme of nomenclature. He is also considered one of the fathers of modern ecology. He is known as the "father of modern taxonomy."

The Linnaean system The Linnaean system classified nature within a hierarchy, starting with three kingdoms. Kingdoms were divided into Classes and they, in turn, into Orders, which were divided into Genera (singular: genus), which were divided into Species (singular: species). Below the rank of species he sometimes recognised taxa of a lower (unnamed) rank (for plants these are now called "varieties").

Nomenclature Refers to a method of assigning (unique) names. In biology: Scientific nomenclature Bacterial nomenclature Botanical nomenclature Zoological nomenclature

Binomial Nomenclature Formal method of naming species. Each organism is given a name consisting of two parts A GENERIC name – states genus – common to a group of closely related organisms A specific name – states species – unique to particular organism - often descriptive of characteristics Primula vulgaris specific GENUS

Basics!! Printed - italics, such as Homo sapiens. There are certain aspects which are universally adopted: Printed - italics, such as Homo sapiens. Handwritten - underlined. The first term (genus) is always capitalized, while the specific descriptor will not be for example, Canis lupus or Anthus hodgsoni. When used with a common name, the scientific name usually follows in parentheses, for example, "the house sparrow (Passer domesticus) is endangered."

Kingdom The top-level, or nearly the top-level. Two kingdoms of living things: Animalia for animals AND Vegetabilia for plants (Linnaeus also treated minerals, placing them in a third kingdom, Mineralia). When single-celled organisms were first discovered, they were split between the two kingdoms: mobile forms - animal phylum Protozoa, and colored algae and bacteria - plant division Thallophyta or Protophyta. However, a number of forms were hard to place, or were placed in different kingdoms by different authors: for example, the mobile alga Euglena and the amoeba-like slime moulds. As a result, Ernst Haeckel suggested creating a third kingdom Protista for them

Five kingdoms

Phylum Between Kingdom and Class. Defined - most basic body-parts shared by that group.  e.g. Chordata (animals with a notochord) Arthropoda (animals with a  jointed exoskeleton) Mollusca (animals with a shell-secreting mantle) Angiosperma (flowering plants) etc. 

Genus In biology, a genus (pl. genera) is a taxonomic grouping. In the classification of living organisms, a genus is considered to be distinct from other such genera. A genus has one or more species If more than one species - morphologically more similar than species belonging to different genera.

Remembering The Order A mnemonic : King Phillip Came Over From Germany Stoned (and numerous variants thereof) = Kingdom, Phylum, Class, Order, Family, Genus, Species. LEARN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Dichotomous Keys Diagram or a table. It is important to note that dichotmous keys have NOTHING to do with biology alone. They are simply a tool. You can make a dichotmous key to describe ANYTHING. fairly simple step by step each splitting of a branch with new info/charactersitic.