-
Jean--Baptiste Lamarck's Philosophie Zoologique published, presenting early ideas on the mechanisms of evolution. Jean-Baptiste Lamarck, a French naturalist, published his theory of evolution. His theory was that evolution occurred through the inheritance of acquired characteristics, or the use/disuse theory.
-
Charles Lyell publishes "Principles of Geology." This pushed a uniformitarian view of geology, or the theory that forces in the past are the same as forces in the present, and that we can use the forces present today to infer things about the past.
-
Darwin begins a five-year voyage on the HMS Beagle. He considers differences among mockingbirds in the Galapagos Islands, his first examination of the evolution of species. His trip around the world lasts five years.
-
Darwin makes his first landing on a tropical shore at St Jago, Cape Verde Islands. Field notebooks begin to be used. From February 1832 to May 1834 the Beagle surveys the east coast of South America. In December arrives in Tierra del Fuego.
-
Early part of the year is spent surveying in Tierra del Fuego and another visit to the Falkland Islands. April to May Darwin and FitzRoy make an inland expedition along the River Santa Cruz. Repeated ports of call in Tierra del Fuego, eventually leaving the Straits of Magellan in June. From June 1834 to September 1835 the Beagle surveys the west coast of South America. Calls at Chiloé Island. From end of July to November Darwin resides in Valparaiso, returns to Chiloé until February 1835
-
Charles Lyell eagerly met Darwin for the first time on 29 October and soon introduced him to the up-and-coming anatomist Richard Owen, who had the facilities of the Royal College of Surgeons to work on the fossil bones collected by Darwin.
-
In mid-December Darwin took lodgings in Cambridge to organise work on his collections and rewrite his Journal.[63] He wrote his first paper, showing that the South American landmass was slowly rising, and with Lyell's enthusiastic backing read it to the Geological Society of London on 4 January 1837. On the same day, he presented his mammal and bird specimens to the Zoological Society.
-
Makes a short geological excursion in Wales. Settles with his wife and young family in Down House, in the village of Downe in Kent. Publishes "The structure and distribution of coral reefs" On a visit to his wife’s family home, Maer in Staffordshire, makes a brief pencil sketch of his theory of ‘descent with modification'.
-
Charles Darwin, working for many years, writes an essay on the theory of evolution. This was never published.
-
Darwin writes out two versions of his developing theory of species evolution: the Sketch of 1842 and Essay of 1844. Following the negative reception of the anonymously published Vestiges of Natural Creation (1844), by the Edinburgh publisher Robert Chambers, Darwin declined to work his essay up for publication.
-
Herbert Spencer begins publishing a projected 10 volume work concerning the principles of synthetic philosophy, in which evolution is invoked as a universal principle that involves progress through stages toward greater complexity.
-
Henry Fairfield Osborn was a student of Cope. He was instrumental in expanding the exhibits and research program at the American Museum of Natural History. He led many fossil hunting expeditions in the American West and trained many of the vertebrate paleontologists in the early 20th century.
-
Alfred Russel Wallace publishes a paper coming to some of the same conclusions as Darwin, including natural selection. Darwin's friends present both Wallace's and Darwin's theories at the Linnean Society.
-
They essentially summaraised Darwins on theories on evolution, thus inspiring him to publish his work sooner than he planned.
-
Darwin, suffering from sickness both in himself and his family , finishes his book "The Origin of Species" and publishes it. It becomes wildly popular.
-
Darwin continued to live in Down, living a quiet life of research and writing. He travelled very little - no more than the occasional short trip to London. He published five further editions of Origin of Species (1860, 1861, 1866, 1869, 1872), and three other works related to the topic of species evolution:
-
In addition, Darwin published seven volumes on plants and worms, dealing with the fertilization of orchids by insects (1862), climbing plants (1865), insectivorous plants (1872),, cross and self-fertilization (1876), different flowers on plants of the same species (1877), movement of plants (1880), and the production of top-soil by worms (1882)
-
Mendel's works with pea plants published, setting the background for the basis of natural selection.
-
Darwin examined human evolution and sexual selection in The Descent of Man, and Selection in Relation to Sex, followed by The Expression of the Emotions in Man and Animals. His research on plants was published in a series of books, and in his final book, he examined earthworms and their effect on soil.
-
Walter Flemming published his results on the study of cell mitosis, detailing the role of chromosomes in cell division.
-
August Weismann publishes findings detailing how important DNA is to heredity, along with germ cell theory - the theory that inheritance only takes place by means of germ cells such as egg and sperm, and that other cells do not pass on their genes.
-
Walter Sutton proposed that chromosomes were the basis for Mendelian inheritance of characteristics.
-
Thomas Hunt Morgan developed studies on the chromosomes of the fruit fly (Drosophila melanogaster), and by 1920 he and other researchers firmly established the chromosome theory of heredity. Further work showed that chromosomes are regular linear arrangements of genes.
-
Barbara McClintock demonstrated that gene order in chromosomes can change by rearrangements and that specific traits in strains of corn are tied to their genetic distribution.
-
DNA is proven to be the genetic material by which inheritance passes from one generation to the next, and thus is the blueprint for evolution.
-
Oswald Avery, Colin MacLeod, and MacLyn McCarty discovered DNA (deoxyribonucleic acid) as the material of the gene. DNA is a long chain molecule made up of four different kinds of molecular groups (nucleotides).
-
James Watson and Francis Crick determined the structure of DNA as a double helix a sort of twisted ladder shape with spines made of sugar and phosphate and rungs made of pairs of the four bases adenine, guanine, thymine, and cytosine.
-
Meselson and Stahl, investigating how the DNA molecule manages to reproduce itself so exactly as cells in a developing organism divide and multiply, confirmed that the double spiral unzips along its length and nucleotides then link up with each half of the chain to form two duplicates of the original model.
-
Miescher isolated DNA. Miescher separated the leucocytes from the bandaging material and the serum. This separation posed a problem for Miescher. Solutions of NaCl or a variety of alkaline or alkaline earth salt solutions used to wash the pus resulted in a “slimy swelling” of the cells, which was impossible to process further. This “slimy swelling” of the cells was presumably due to high-molecular-weight DNA, which had been extracted from cells that had been damaged.
