植物学及园艺学英文版 botany and horticulture (12).ppt

1、Evolution of the Theory of Evolution,Carl Linnaeus (1707 1778) Swedish biologist considered the father of modern taxonomy. Most of his life as a student and professor (from 1741) was spent at Uppsala University. Invented the bionomial nomenclature for organisms (e.g., Homo sapiens, Taraxacum officin

2、ale).,Georges-Louis Leclerc Comte de Buffon (1701 1788) French mathematician, biologist, cosmologist, naturalist. Founder of the science of biogeography Keeper of the Jardin du Roi (now Jardin des Plantes) in Paris. Author of the incredible Histoire naturelle (44 volumes), translated into many langu

3、ages. It contained everything known about the natural world at the time. It can be found online at rs.fr,Erasmus Darwin (1731 1802) Medical doctor , poet and author Had 14 Children with 2 wives and a mistress Grandfather of Charles Darwin Poems about nature and evolution: The Economy of Vegetation T

4、he Loves of the Plants The Temple of Nature Prose works for scientists: Zoonomia (1794 1796) Phytologia (1800),Erasmus Darwins Take on Evolution Life appeared spontaneously early in earths history Self-generated variation and diversification led to all modern plants and animals, including humans No

5、original creation or divine intervention was necessary; nature had its own “laws of nature.” (Erasmus Darwin was apparently an unbeliever, but never publicly denied the existence of God.) Mechanism of evolution: development of useful characteristics passed on to succeeding generations basically a pr

6、ecursor to, Lamarcks theory of the inheritance of acquired characteristics.,Jean-Baptiste Lamarck (1744 1829),Made important contributions to cell theory, botany, invertebrate zoology, and evolutionary theory. He published a book Philosophie Zoologique stating that species are created by spontaneous

7、 generation and change and increase in complexity over time (transmutation) Evolutionary changes are caused by the need to adapt to changes in the environment striving for improvement.,Lamarcks 2 Basic Principles: The Law of Use and Disuse If a body part is used, it becomes more developed and strong

8、er (striving for improvement). The Inheritance of Acquired Characteristics Characteristics of an organism that are developed or obtained through Use and Disuse can be passed on to offspring.,Georges Cuvier (1769 1832) French naturalist and zoologist who compared fossil animals with living animals an

9、d established the fields of comparative anatomy (study of body parts) and paleontology (study of fossils).,Cuviers Ideas Cuviers work paved the way for the theory of evolution, but he himself did not believe in evolution. He believed that all present organisms had been created exactly as they were n

10、ow and had never changed, pointing out that mummified cats and other animals in ancient Egyptian tombs were identical to those of today. He believed that fossils were the remains of previously existing organisms that had become extinct through some great catastrophe. He developed this Theory of Cata

11、strophism He ridiculed Lamarcks theory,Thomas Malthus (1766 1834) 1798 wrote an essay Principles of Population, and reasoned that in nature, plants and animals produce far more offspring than can survive. If the human population continued to grow unchecked, sooner or later there would be insufficien

12、t living space and food for everyone.,Charles Lyell (1797-1875) Rejected the Theory of Catastrophism Developed the Theory of Uniformitarianism - evolution happens through gradual changes, not catastrophic events Published book Principals of Geology - stated earth is old and changing slowly,Charles D

13、arwin (1809-1882 ) Sailed on a 5 year voyage on British ship HMS Beagle to the coast of South America As he traveled along islands that were isolated from the mainland, he saw slight differences in species,Especially along the Galapagos Islands (West Indies) he noticed that the finches there had mod

14、ified characteristics on each island,He concluded there must have been a common ancestor from the mainland, and different characteristics evolved to fill different niches on each island (different type of food).,He read the essays and books of previous scientists mentioned, and compiled all the prev

15、ious theories and developed the theory of Descent with Modification by Natural Selection Published the book On The Origin of Species in 1859,This was very controversial at the time, as it went against the Creationist beliefs of the Catholic Church,Alfred Russel Wallace (1823-1913) Developed a theory

16、 of evolution very similar to Darwins at the same time as Darwin This prompted Darwin to quickly publish his theory Today both men are credited with the Theory of Natural Selection,Darwin-Wallace Theory of Evolution 1. Overproduction - species produce more offspring than needed, and some will die 2.

17、 Struggle for Existence - there will be competition for resources 3. Variation - individuals have variations in characteristics 4. Survival of the Fittest - those equipped with the best variations (against predators, parasites, disease, starvation environmental extremes) will survive long enough to

18、reproduce and the less fit will die 5. Natural Selection - the best traits will be passed on to offspring, others will die/disappear 6. Evolution of new Species - gradually variations accumulate so that new species have formed,Example of Evolution the long neck of the giraffe,b) Darwins view,Problem

19、 with Darwins theory:how do variations arise?There was no knowledge of genes, chromosomes, DNA, mutations etc. at the time.This weakness caused Darwins theory to not be fully accepted.,Gregor Mendel (1822-1884),Worked with pea plants and documented inheritance patterns When he died his work had not

20、been accepted,August Weismann (1834-1914),He cut off tails of mice for 22 generations and all were born with normal tails Developed germ plasm theory - stating (in a multicellular organism) inheritance only takes place by the gametes. Other cells of the body (somatic cells) do not function as agents

21、 of heredity.,Weismanns idea rules out the inheritance of acquired characteristics as proposed by JeanBaptiste Lamarck The largely random process of mutation, which must occur in the gametes (or stem cells that make them) is the only source of change for natural selection to work on.,Hugo deVries (1848-1935) Perfomed experiments very similar to Mendels and developed t