Evolution Natural and Artificial Selection

Vocabulary (in Sections 10.1, 10.2, 10.3) Evolution Natural Selection Artificial Selection Species Genetic Variation Adaptation Fitness Population

Evolution Evolution is simply change over time. – The change usually creates more complexity but not necessarily. – In biology, evolution is associated with the change in genetic composition of a population over successive generations. – For biological evolution to take place, there has to be a form of genetic inheritance. In today’s world, inheritance is through DNA, though there are other molecules (RNA for example) capable of doing DNA’s job.

Variation In order for biological evolution to take place, there has to be genetic variation. Genetic variation is defined as the differences in genomes (the genes) found among members of a species. The variation in genes within a population is a of genetic mutation. – Without genetic mutation, eventually, due to genetic drift, there would be no variation.

Natural Selection Natural selection is the creative force that makes biological evolution possible. Natural selection is defined as the process by which heritable traits that increase an organism’s chances of survival and reproduction are favored than less beneficial ones. – The traits are encoded in genes and natural selection “selects” which genes are most adaptive in a given environment (defined by habitat and ecological niche).

Natural Selection Those individuals whose genes are more well adapted to an environment are more fit and more likely to pass on their genes. Over time, through the process of genetic mutation and natural selection, species evolve (called speciation) – giving rise to new species. – Eventually, the original species might go extinct at the hands of the “new,” potentially better adapted (more fit), species they have spawned.

Darwin’s Finches

Interesting Website on Evolution _2_12.html#1

Darwin’s Bibliography by Date 1829–1832. [Records of captured insects, in] Stephens, J. F., Illustrations of British entomology [1] 1835: Extracts from letters to Professor Henslow (read at a meeting of the Cambridge Philosophical Society on 16 November 1835, with comments by John Stevens Henslow and Adam Sedgwick, and printed for private distribution dated 1 December 1835.[2] Selected remarks had been read by Sedgwick to the Geological Society of London on 18 November 1835, and these were summarised in Proceedings of the Geological Society published in 1836.[3] Further extracts were published in the Entomological Magazine and, with a review, in the Magazine of natural history.[2]) 1836: A LETTER, Containing Remarks on the Moral State of TAHITI, NEW ZEALAND, &c. – BY CAPT. R. FITZROY AND C. DARWIN, ESQ. OF H.M.S. 'Beagle.'[4] : Zoology of the Voyage of H.M.S. Beagle: published between 1839 and 1843 in five Parts (and nineteen numbers) by various authors, edited and superintended by Charles Darwin, who contributed sections to two of the Parts: 1838: Part 1 No. 1 Fossil Mammalia, by Richard Owen (Preface and Geological introduction by Darwin)

Darwin’s Bibliography by Date 1838: Part 2 No. 1 Mammalia, by George R. Waterhouse (Geographical introduction and A notice of their habits and ranges by Darwin) 1839: Journal and Remarks (The Voyage of the Beagle) 1842: The Structure and Distribution of Coral Reefs 1844: Geological Observations on the Volcanic Islands visited during the voyage of H.M.S. Beagle 1846: Geological Observations on South America 1849: Geology from A Manual of scientific enquiry; prepared for the use of Her Majesty's Navy: and adapted for travellers in general., John F.W. Herschel ed. 1851: A Monograph of the Sub-class Cirripedia, with Figures of all the Species. The Lepadidae; or, Pedunculated Cirripedes. 1851: A Monograph on the Fossil Lepadidae, or, Pedunculated Cirripedes of Great Britain 1854: A Monograph of the Sub-class Cirripedia, with Figures of all the Species. The Balanidae (or Sessile Cirripedes); the Verrucidae, etc. 1854: A Monograph on the Fossil Balanidæ and Verrucidæ of Great Britain 1858: On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection (Extract from an unpublished Work on Species)

Darwin’s Bibliography by Date 1859: On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life 1862: On the various contrivances by which British and foreign orchids are fertilised by insects 1865: The Movements and Habits of Climbing Plants (Linnean Society paper, published in book form in 1875) 1868: The Variation of Animals and Plants under Domestication 1871: The Descent of Man, and Selection in Relation to Sex 1872: The Expression of Emotions in Man and Animals 1875: Insectivorous Plants 1876: The Effects of Cross and Self Fertilisation in the Vegetable Kingdom 1877: The Different Forms of Flowers on Plants of the Same Species 1879: "Preface and 'a preliminary notice'" in Ernst Krause's Erasmus Darwin 1880: The Power of Movement in Plants 1881: The Formation of Vegetable Mould through the Action of Worms