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Biology is the science of life. It concerns the characteristics and behaviors of living things, of both today and long ago, how they come into being, and what interactions they have with each other and their environments. The term "biology" was coined in the late 1700s by French naturalists Pierre-Antoine de Monet and Jean-Baptiste de Lamarck.
Overview of biology
Biologists study life over a wide range of scales:
- at the atomic and molecular scale, through molecular biology, biochemistry and genetics (study of organic molecules, their structures, properties and interactions)
- at the cellular scale, through cell biology
- at the multicellular scale, through physiology and histology
- at the level of the population of organisms, in population genetics
- on the multi-species scale of lineages, through systematics (comparison and classification of living organisms), anatomy, ontogeny, and ethology (behavior and adaptability)
- to the top of the scale, ecology (study of ecosystems, interactions between living organisms and their environment)
Major Branches of Biology
Aerobiology -- Anatomy -- Astrobiology -- Biochemistry -- Bionics -- Biogeography -- Bioinformatics -- Biophysics-- Biotechnology -- Botany -- Cell biology -- Chorology -- Cladistics -- Cytology -- Developmental biology -- Disease (Genetic diseases, Infectious diseases) -- Ecology (Theoretical ecology, Symbiology, Autecology, Synecology)-- Ethology --Entomology-- Evolution (Evolutionary biology) -- Evolutionary developmental biology ("Evo-devo" or Evolution of Development) -- Freshwater Biology -- Genetics (Population genetics, Quantitative genetics, Genomics, Proteomics) -- Histology -- Immunology -- Infectious diseases -- Pathology -- Epidemiology -- Limnology -- Marine biology -- Microbiology (Bacteriology) -- Molecular Biology -- Morphology -- Mycology / Lichenology -- Neuroscience (Neuroanatomy, Neurophysiology, Systems neuroscience, Biological psychology, Psychiatry, Psychopharmacology, Behaviorial science, Neuroethology, Psychophysics, Computational neuroscience, Cognitive science)-- Oncology (the study of cancer) -- Ontogeny -- Paleontology (Palaeobotany, Palaezoology)-- Phycology (Algology) -- Phylogeny (Phylogenetics, Phylogeography) -- Physiology -- Phytopathology -- Structural biology -- Taxonomy -- Toxicology (the study of poisons and pollution) -- Virology -- Zoology
Related Disciplines
Medicine -- Physical anthropology
People and History
Famous biologists -- History of biology -- Nobel prize in physiology or medicine -- Timeline of biology and organic chemistry
What are our priorities for writing in this area? To help develop a list of the most basic topics in Biology, please see Biology basic topics.
Evolution and biology
One of the central, organizing concepts in biology is that all life has descended from a common origin through a process of evolution. Charles Darwin was the first to rigorously argue this idea, which he did with his proposal of natural selection as an evolutionary mechanism. The evolutionary history of a species (which includes the characteristics of the species from which it descended) and its relationship to other species is called its phylogeny. Widely varied approaches to biology generate information about phyologeny. These include the comparisons of DNA sequences conducted within molecular biology or genomics, and comparisons of fossils or other records of ancient organisms in paleontology. Biologists organize and analyze evolutionary relationships through various methods, including phylogenetics, phenetics, and cladistics. Major events in the evolution of life, as biologists currently understand them, are summarized on this evolutionary timeline.
Classification of life
The classification of living things is called systematics, or taxonomy, and should reflect the evolutionary trees (phylogenetic trees) of the different organisms. Taxonomy piles up organisms in groups called taxa, while systematics seeks their relationships. The dominant system is called Linnaean taxonomy, which includes ranks and binomial nomenclature. How organisms are named is governed by international agreements such as the International Code of Botanical Nomenclature (ICBN), the International Code of Zoological Nomenclature (ICZN), and the International Code of Nomenclature of Bacteria (ICNB). A fourth Draft BioCode was published in 1997 in an attempt to standardize naming in the three areas, but it does not appear to have yet been formally adopted. The International Code of Virus Classification and Nomenclature (ICVCN) remains outside the BioCode.
Traditionally, living things were divided into five kingdoms:
However, this five-kingdom system is now considered by many to be outdated, and if one does not want to hyperinflate the number of kingdoms, one can use the three-domain system. These domains reflect whether cells have nuclei or not as well as differences in cell membranes / cell walls.
- Archaea -- Eubacteria -- Eukaryota
The distinction between life and non-life is difficult, there is also a series of intracellular "parasites" that are progressively less alive in terms of being metabolically active:
External links and resources
Links
- Kimball's Biology Pages, http://www.ultranet.com/~jkimball/BiologyPages/ : An online searchable textbook.
- The Tree of Life, http://tolweb.org/tree/phylogeny.html : A multi-authored, distributed Internet project containing information about phylogeny and biodiversity.
- The Journal of Biology, http://www.jbiol.com : A small, but free, research journal
- BioCode, http://www.rom.on.ca/biodiversity/biocode/biocode1997.html : A proposal for organism naming
Further reading
- Lynn Margulis: Five Kingdoms: An Illustrated Guide to the Phyla of Life on Earth, 3rd ed., St. Martin's Press, 1997, paperback, ISBN 0805072527 (There are numerous other editions)
- Neil Campbell, Biology: Concepts & Connections (4th edition), Benjamin-Cummings Publishing Company, 2002, hardcover, 781 pages, ISBN 080536627X A college-level textbook.