Biology: Study of Life and Ernst Mayr

• Biology is the study of life forms and living processes.
• The awe or fear evoked by inanimate and animate objects was a common feature.
• Description of living organisms including human beings began later in human history
• Societies with anthropocentric views of biology achieved limited biological knowledge
• Necessary, systematic descriptions of life forms led to detailed identification, nomenclature, and classification systems
• Recognizing similarities among living organisms led to cultural movements for biodiversity conservation
• Later chapter classify animals and plants from a taxonomist's perspective.

Ernst Mayr (1904–2004)

• Ernst Mayr (1904–2004): Harvard evolutionary biologist called "The Darwin of the 20th century"
• Mayr joined Harvard's Faculty of Arts and Sciences in 1953 and retired in 1975
• He became Alexander Agassiz Professor of Zoology Emeritus
• His 80-year career spanned ornithology, taxonomy, zoogeography, evolution, systematics, and the history/philosophy of biology
• Mayr established species diversity origin as evolutionary biology's central question
• He pioneered the modern definition of a biological species
• Mayr won the Balzan Prize (1983), International Prize for Biology (1994), and the Crafoord Prize (1999)
• He passed at 100.

Chapter 1: The Living World

• The range of living types and extraordinary habitats is amazing and leaves us speechless
• Ecological conflict and cooperation evoke a deep sense of wonder

Diversity in the Living World

• There are many various living organism like potted plants, insects, birds, your pets or other animals and plants
• Some organisms are microscopic
• Increasing the observation area increases the range and variety of organisms seen
• Each different plant, animal, or organism represents a species
• Known and described species range between 1.7-1.8 million.
• Biodiversity is the number and types of organisms present on earth

Nomenclature

• Millions of plants/animals exist, known by local names that vary by location
• Standardizing organism names is necessary for clear communication
• Nomenclature is the process of standardizing living organism names
• Nomenclature requires correct organism description.

Identification

• Assigning a scientific name to each organism is vital to allow biologists to understand the species all over the world
• Acceptable principles/criteria are defined in the International Code for Botanical Nomenclature(ICBN).
• International Code of Zoological Nomenclature (ICZN) are used for animals taxonomy
• Scientific names ensure each organism has a unique name
• Organism descriptions should enable people worldwide to identify it by the same name.

Binomial nomenclature

• Universal principles helps to provide organisms with a scientific
• Each name has a generic name and a specific epithet
• Binomial nomenclature gives each name two components
• Carolus Linnaeus created the system of binomial nomenclature
• Mango is called Mangifera indica
• Mangifera represents the genus
• Indica is a particular species, or specific epithet

Rules of Nomenclature

• Biological names are generally in Latin and written in italics
• First word in a biological name represents the genus
• Second component denotes the specific epithet
• Handwritten biological names must be underlined separately, or italicized when printed
• The first word denoting the genus starts with a capital letter
• Specific epithet start with a small letter
• Author name appears in abbreviated form after the specific epithet
• E.g., Mangifera indica Linn represents Linnaeus originally described the species

Classification

• Impossible to study all living organisms make classification necessary
• Classification groups organisms into convenient categories based on observable characters
• Using terms like plants, animals, dogs, or insects leads to associated characters with that group
• Dogs will not be confused to cats
• Scientific term for categories is taxa

Taxa

• Taxa can indicate categories at varying levels ("plants," "wheat")
• Animals, mammals, and dogs are taxa at different levels
• Living organisms are classified into different taxa
• Taxonomy is the process of classification
• Essential components of modern taxonomy are related to external and internal structure, cell structure, development process and ecological information
• Characterization, identification, classification, and nomenclature are basic to taxonomy

Systematics

• Taxonomy is not new
• Humans are interested about organism
• Early classifications focused on organism uses for food, clothing, and shelter
• Human interest moved towards organism relationships
• Systematics is the branch of study that involves the relationships among taxa
• Systematics is derived from systema
• Systema means systematic arrangement of organisms
• Linnaeus used Systema Naturae as the title
• Systematics now includes identification, nomenclature, and classification
• Systematics takes into account evolutionary relationships between organisms

Taxonomic Categories

• Classification involves steps that represents a rank or category
• Taxonomic category is a part of overall taxonomic arrangement together
• Taxonomic hierarchy is all categories
• Each category represents a unit of classification
• Taxonomic category is also known a taxon (pl.: taxa)
• Animals species/genus
• Taxonomic categories and hierarchy is represented by insects with three pairs of jointed legs
• Insects are recognisable concrete objects which can be classified
• Groups of organism is a category
• Category represents rank
• Each rank, or taxon, represents a classification unit
• Taxonomic groups/categories are distinct biological entities
• Taxonomical studies of organisms are categorised into kingdom, plant division, class, order, family, genus and species

Species

• All known kingdoms are lowest as species category
• Placement relies on organism character knowledge to identifying similarities and differences
• Species needs fundamental similarities in the individual
• Species distinguished from closely related species with distinct morphological differences
• Mangifera indica (mango), Solanum tuberosum (potato) & Panthera leo (lion) all represent different species
• Indica, tuberosum and leo represent specific epithets
• Mangifera, Solanum, and Panthera represent genera
• Each genus may have multiple specific epithets
• Panthera has species Panthera tigris
• Solanum includes species nigrum and melongena
• Humans is species sapiens
• Genera is the term for Homo

Genus

• Genus contains relatable species and its characteristics in species
• Genus is known as aggregates of close species
• Potato and brinjal are different species in the same genus Solanum.
• Lion (Panthera leo), leopard (P. pardus) and tiger (P. tigris) have common features and represent the Panthera
• Panther differ from Felis

Family

• Family consists out of related genera
• Family is characterised by reproductive features and vegetative
• Genera Solanum, Petunia, and Datura form Family Solanaceae in plants
• Genus Panthera (lion, tiger, leopard) is put along with genus, Felis (cats) in the family Felidae in animals
• Cats and dogs may show similar characteristics although belong to Felidae and Canidae

Order

• Species and Genus are categories with similar characters
• Higher taxonomic categories have similar characteristics
• An order is the result of assemblage and a higher category
• Plant families Convolvulaceae, Solanaceae belong to order Polymoniales
• Carnivora includes Felidae and Canidae

Class

• Class includes similar orders
• Primata (monkey, gorilla, gibbon) in class Mammalia and Carnivora (tiger, cat, dog).

Phylum

• Phylum consists out of animals like fishes, amphibians, reptiles, birds and mammals
• Phylum share characteristics like notochord & dorsal neural
• For plants, classes are with categories as Division

Kingdom

• All animals represent to kingdom Animalia
• Plants represent to kingdom Plantae
• Taxonomists have developed sub-categories to facilitate more
• Common characteristics decrease as we move higher from species to kingdom
• Table Organisms with their Taxonomic Categories: Man, Housefly, Mango, Wheat