Chanag in living organisms

1- Mechanism of evolution: Evolution is a gradual change that continues through a long period of time and leads to the appearance of new species from old ones. 2- Lamark thought that the main factors in evolution are: A- The law of use and disuse. B - The inheritance of the acquired characters. - The criticism of Lamark was by the exps. of weismann and (1887) or rats. 3- Darwins' theory explained evolution according to: A- Great producitivty. B- Variations and differences. C- Natural selection. D- Trans formation and changes. Criticism of Darwin's theory: 1- Somatic chagnes are not enough for selection. 2- Struggle for selection is not general 3- Struggle for existence does not explain the sudden changes or disappearance of some living organisms like reptiles in jurassic period. 4- Not explain sudden appearance of some tiliter. - The Modern synthetic theory explains the appearance of new species to the changes in population not in the individuals, the factors that lead to evolution are: A- Population genetics [genetic equilibrium - genetic drift] B- Variation in the individuals of species. C- Natural selection and adaptation. D- Isolation and speciation. 5- A population is a group of individuals of a certain species live in a certain environment. 6- The genes of all characters in all individuals of a population are considered as a common source of genes or as gene pool 7- If one of the factors that keep the genetic equilibrium is not full filled genetic drift takes place. 8- The fittest organisms are those who can obtain their food, protect and raise their young until they mature and become able for reproduction. 9- The natural selection means the selection of individuals with suitable traits for success in life. 10- The natural selection occurs by several ways such as: A- The natural environmental conditions (light, temperature...etc) B- The living components of the environment. 11- Examples of natural selection is Biston betularia - cepaea nemoralis snails. 12- Isolation and speciation are: a) Anagenic speciation. b) Phyletic speciation , ex: Darwin's finches in Galapagosisland. 13- Evidences that support evolution: A- Fossil studies B- Taxonomy and evolution C- comparative anatomy D- The vestigial structures e- The physiological resemblance f- Emberyology and evolution 14- Fossil is used to correlate between different layers of sedimentary rocks to determine their ages. 15- The important conditions for fossil formation: a) presence of hard skeleton b) It is buried after death directly c) sutiable medium as we go deeper in the earth , wefind fossils of simple organisms. 16- Types of fossils: A- Fossil of an entire organism B - Fossil of the hard part of the organism C- Moulds and casts D- The petrified remains e- The prints of living organism 17- Both mammoth and insects buried in amber represent fossils of an entire organism. 18- Petrifaction or mineral replacement is the transformation of the organic parts of the living organism into mineral substances keeping all the details of the living organisms. 19- Moulds may be: A- Solid mould which shows the internal details. B- Empty mould which shows the external details. 20- Casts are marks left by living organisms skeleton in the sedimentary rocks after its death. 21- Prints are what was left by the organism in sedimentary rocks when it was alive. 22- scientists proved that every layer or group of layers of sedimentary rocks has its own fossils, the age of fossils can be determined by using radio active elements. 23- Deep layers contain fossils of simple organisms but surface layers contain fossils of higher organisms. 24- Fossils show the succcession of life forms through life epochs also the relationship between two different groups of plants or animals. 25- A complete groups of fossils recording the evolution of elephants and horse were discovered. 26- Species is a group of living organisms that produce fertile off springs similar to their parents if crossed together. 27- Intermediate link, is a contemporary or extinct species of living organism that has the characters of two successive groups of living organisms and fill the gap between them examples: , lung fish, Duck bill, Archaeopteryx, fossils of ferns carrying seeds, and echinodermata. 28- Similarities between living organisms is an evidence for evolution because it is an evidence for the presence of a common origin. 29- vestigial or structures are organs which used to be well developed in early ancestors of vertebrates but they disappeared or diminished in contremproary species, they were important for early ancestors of living organisms and become with no function by the present organisms. 30- Physiology is the study of how living organisms perform their biological activities the living organisms resemble each other in carrying out different biological functions. 31- Emberyology is the study of the different stages of the emberyo development in plants and animals, the early emberyonic stages of different animals are very similar to each other. 32- The gedogical Distribution and evolution where: Distribution of any group of living organisms depends on: A- Its ability to adapt with climatic factors. B- The geographic barriers. C- Competing with other living organisms.