PPT-Natural Selection The Theory of Evolution

Evolutionary Ideas A lthough Darwin is given much credit for evolutionary theory he was not the first person to come up with the idea Evolution is the change in a population over time The concept of evolution had been discussed for more than 100 years prior to Darwins theory. Scientific Theory. Social use of the word “theory”. Not the same as in science. Implies a hunch or a casual guess. Scientific Theory. 1. Highly probable explanation based on vast collections of scientific data. The Importance of Evolution in Ecology. Ecologists study proximate or “how” questions:. How nutrients flow through ecosystems. Evolutionary biologists study ultimate or “why” questions:. Why does a stickleback fish have armor in one lake but not another?. IB Diploma Biology. A . Return. to Senn Island…. Evolution & Natural Selection (5.1-5.2). IB Diploma Biology. Pentadactyl Limbs. Organism (type). Function of pentadactly limb. Crocodile (reptile). Motivation. Most powerful mode of evolution. Explains observation of Descent with Modification. Nonrandom survivorship/reproduction of individuals based on particular features of their phenotype. . Any environmental agent may be the cause of natural selection. Unit:09. Lesson: 01. Be prepared to share your response to the following:. Biological evolution happens at the __________ level, not the individual organism level.. All three definitions mention genetic changes or changes in allele frequency within a population from one generation to the next.. Recent Evolution in Humans. Evolution is very much still happening today — and it's happening to us.. Right here, right now.. Our genes constantly change over time thanks to the power of selection.. Chapters 14-18. Charles . Darwin. , DOB 1809, . On the Origin of Species by Means of Natural Selection. , . HMS Beagle –. 1831-36. Greeks – life arose in water and more complex followed simpler ones. Early atmosphere, evidence, natural selection and disease agents influence natural selection. . Introduction . Evolution “ simple” definition: change over time. Evolution helps us to understand the history of life.. Gibson. Geoscience Research Institute. www.grisda.org. Summary. Evolution is the theory that all organisms have descended from a common ancestor by unguided (natural) processes.. The Cambrian Explosion contradicts the pattern . (Hons), Zoology. Panjab University, Chandigarh. ORIGIN OF UNIVERSE. BIG BANG THEORY. Thermonuclear explosion. Origin of universe occurred 20 . bya. .. ORIGIN OF EARTH. NEBULAR HYPOTHESIS. Condensation of gases under Gravitational force. Chapter 17: Processes of Evolution. Early Beliefs. 19. th. century: discovered species shared many traits, but lived in different parts of the world. Problematic – species only looked similar on the outside, but inside were very different . Charles Robert Darwin. . (1809-1882) was an English naturalist who . born on 12th February, 1809. at Shrewsbury, England. . He went on . voyage. . (trip, expedition, tour). for five years (1831 to 1836) and . wallace. and was explained in book “ on the origin of species by means of Natural Selection . . Darwin put the theory based on his observations as he travelled round the world on the ship Beagle.. Diversity and Evolution Of Living Organisms . The scientific theory of evolution is the . organizing . principle. of life science.. 2. The scientific . theory of . evolution is supported . by . multiple forms.