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Aristotle ordered the diversity of known animals into two groups: enaimos(with red blood) and, anaimos(without red blood); and plants (including fungi). -
Until 16th Century, the Church imposed the idea that the Earth was the center of the Universe. -
Heliocentric theory, proposed by Aristarchus of Samos and Nicolaus Copernicus -
Until the 18th Century, naturalists believed that divine or Holy creation was the cause for the Universe, life and species to originate and remained the same. -
Carolus Linnaeus in his book Systema Naturae determined that species would be ordered in hierarchical or classification taxonomic categories and established the kingdoms Vegetabilia and Animalia -
George Louis Leclerc suggested that diet, climate and customs made species change to adapt to the new environment, becoming new ones with inheritable characteristics. -
Notable advances in chemical investigation (photosynthesis was discovered; biogeochemical cycles, combustion, and respiration were understood).
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In the 19th Century, Lamarck classified animals in vertebrates (with spinal column and cranium) and invertebrates (without spinal column and cranium), and plants. -
Jean-Baptiste Lamarck reformulated the theory of spontaneous generation: he thought that from the microbes descended all the species that inhabit the world. -
Jean-Baptiste Lamarck suggested that organisms are in greater development during their lifetime, and these acquired characteristics are inherited to their offspring. -
Louis Pasteur did a series of experiments with which he demonstrated that microbes didn’t appear through spontaneous generation. -
Charles Darwin published The Origin of Species, where he referred to three aspects of evolution; these are adaptation, transformation and diversification of species (with the help of natural selection). -
Ernst Haeckel created a system of three kingdoms, he designated the name “Protista” to encompass all unicellular organisms. -
Albert Einstein believed that the Universe was static, introduced the cosmological constant, which was an unknown force opposite to gravity that kept an equilibrium. -
Proposed by Alexander Frieddman, the universe will stop its expansion and will collapse back to its starting point, this will happen indefinitely. -
In The Origin of Life, Alexander Oparin proposed that life on Earth had originated in a primitive atmosphere not rich in oxygen. Also, he proposed that the first living beings must have risen from inorganic matter (chemical evolution). -
Georges Lemaître proposed that the phenomenon that caused the expansion was a great explosion that took place 14,000 million years ago -
Edwin Hubble deduced that Universe is in motion, and the appearance of stillness is due to the huge distances between the galaxies and the further they were, they shifted to red (Doppler effect involved). -
Édouard Chatton observed that the presence or absence of the nucleus was the most notorious characteristic of the cell, he divided them in eukaryotes and prokaryotes. -
Herbert Faulkner Copeland separated bacteria from the protista creating the fourth kingdom of cells without organelles which he called Monera. -
George Gamow, Ralph Alpher and Robert Herman predicted the background radiation, temperature of the Universe and redshift -
Suggested by Fred Hoyle, Hermann Bondi, and Thomas Gold. It opposes to the Big Bang and Big Crunch, proposes that the Universe is in constant expansion due to the continuous creation of new matter. -
Harold Urey, after reading Oparin’s book, deduced the initial compounds of the reducing atmosphere of primitive Earth. -
H. Urey and Stanley L. Miller designed a model of the hydrosphere of primitive Earth, which resulted in the simplest reduced compounds turned into complex organic molecules like amino acids, proving the heterotroph hypothesis. -
Robert Whittaker documented a wide and diverse subgroup of species, they were not plants but another kingdom, Fungi. -
Many scientists independently proposed the existence of a first biologic world based on RNA molecules. -
Small molecules of RNA that performed catalytic functions were discovered on living beings, they were called ribozymes. -
Suggested by Alan Guth explains that in the initial seconds of the explosion, the Universe expanded faster (inflationary), which agrees with the homogeneity observed. -
Carl Woese established the new classification scheme of three domains: Bacteria, Archaea and Eukarya. -
Lynn Margulis and Karlene Schwartz created a new category called "Super Kingdom", to place prokaryote and eukaryote super kingdoms; creating two subkingdoms under prokaryote one: Eubacteria and Archaeobacteria.