Evolutionary Biology: Ernst Mayr

Ernst Mayr

• Born on 5 July 1904 in Kempten, Germany.
• Renowned Harvard University evolutionary biologist; dubbed ‘The Darwin of the 20th century’.
• Joined Harvard's Faculty of Arts and Sciences in 1953 and retired in 1975 as Alexander Agassiz Professor of Zoology Emeritus.
• Research encompassed ornithology, taxonomy, zoogeography, evolution, systematics, and the history and philosophy of biology.
• Significantly emphasized species diversity as a pivotal question in evolutionary biology.
• Established a widely accepted definition of biological species.
• Recipient of the Balzan Prize (1983), International Prize for Biology (1994), and Crafoord Prize (1999), known as the triple crown of biology.
• Died at age 100 in 2004.

The Living World

• The diversity of living organisms is vast and spans various habitats like mountains, forests, oceans, lakes, and deserts.
• The scientific nomenclature involves italicized Latin names; for example, Mangifera indica (mango).
• Binomial nomenclature consists of two parts: the genus (first word) and the specific epithet (second word).
• Key rules for naming:
  • Latinized names written in italics.
  • Genus name begins with a capital letter; specific epithet starts with a lowercase letter.
  • Both parts are underlined when handwritten.
  • The abbreviated author name follows the species name, e.g., Mangifera indica Linn.

Classification and Taxonomy

• Classification is essential for organizing living organisms into categories based on observable characteristics.
• Systematics includes identification, nomenclature, and classification, considering evolutionary relationships.
• Taxonomic hierarchy structures categories into ranks such as kingdom, phylum, class, order, family, genus, and species.

Taxonomic Categories

• Each category represents a rank or unit of classification known as a taxon (plural: taxa).
• Species: Groups of organisms with fundamental similarities; identifiable based on distinct morphological differences. Examples:
  • Mangifera indica (mango)
  • Solanum tuberosum (potato)
  • Panthera leo (lion)
• Genus: Aggregates related species with shared characteristics. Example:
  • Genus Solanum includes potato and brinjal.
  • Genus Panthera consists of lion, leopard, and tiger.

Higher Taxonomic Categories

• Family: Composed of related genera with fewer similarities, classified based on vegetative and reproductive features. Example:

  • Family Solanaceae includes Solanum, Petunia, and Datura.
  • Family Felidae includes cats (genus Felis) and big cats (genus Panthera).

• Order: Includes families with some shared characteristics. Example:

  • Order Carnivora encompasses families Felidae and Canidae.

• Class: Groups related orders. Example:

  • Class Mammalia includes order Primata (monkeys, gorillas) and order Carnivora (tigers, cats).

• Phylum: Comprises all classes of animals with common features, such as presence of notochord. Example:

  • Phylum Chordata includes classes pertaining to fish, amphibians, reptiles, birds, and mammals.