3.Evidence from paleontological or fossil research character. Molecular evidence. The conditions on the earth that favoured chemical evolution were very high temperature, volcanic storms and reducing atmosphere that contained CH4,NH3, water vapour, etc. (c) Other examples of homology are vertebrate hearts or brains. EVOLUTION EVIDENCES FOR EVOLUTION. In a diploid, let p and q represent frequency of allele A and a. EVOLUTION. According to the several theories of Evolution: Learn more about evolution and its theories from the topics given below: Your email address will not be published. (d) The Big Bang theory states that a huge explosion occurred, the universe expanded, temperature came down and hydrogen and helium were formed later. Dec 18, 2020 - Evolution - Class 12, Biology | EduRev Notes is made by best teachers of Class 12. (ii) The earth was supposed to have been formed about 4.5 billion years back in the solar system of the milkyway galaxy. The probability that an allele A with a frequency of p appears on both the chromosomes of a diploid individual is simply the product of the probabilities. Paleontological evidence and 4. This is also true for microbes against which antibiotics or drugs have been used. (v) Embryological evidences Study of comparative embryology shows common patterns of development. Anatomy and morphology 2.1. These are degenerate, non-functional and rudimentary organs to the possessor, while correspond to fully developed and functional organs of related organisms. Vestigial organs like homologous organs provide evidences for organic evolution. Rate the test and post your comments. (a) Organs which are anatomically different but functionally similar are called analogous organs. (ii) These molecules were like RNA, protein and polysaccharides. Darwin’s theory of evolution. In this live Grade 12 Life Sciences show we take a close look at Evolution. Sign in. What is Charles Darwin’s theory of evolution? A study of fossils in different sedimentary layers indicates the geological period in which they existed. a)Homologus organs. The theory of evolution is based on the idea that all species are correlated and progressively varies with time. Question from very important topics are covered by NCERT Exemplar Class 12.You also get idea about the type of questions and method to answer in your class 12th … (iii) Cellular life form first evolved about 2000 million years ago. Evidence for Evolution. EVIDENCES OF ORGANIC EVOLUTION . (ii) Spiny anteater and scaly anteater belong to different orders of class-Mammalia. Some traits are consistently passed on from their parent to the offspring. Required fields are marked *. III. Evidences of Evolution of Class 12. B. Analogous and vestigial organs. Students who are in class 12th or preparing for any exam which is based on Class 12 Biology can refer NCERT Biology Book for their preparation. For example, wings of butterfly and birds. We have number of evidences to prove the biological evolution namely fossils, comparative anatomy and embryo development pattern. But, none of the variants got wiped out completely, Examples of evolution by anthropogenic action is the appearance of resistant cells/entities in a time span of months or years as  opposed to centuries, Through these evidences it was also indicated that evolution is not a directed process in the context of determinism rather is a stochastic process basis the chance events in nature and chance mutations in entities, Entities are better adapted to survive in an otherwise hostile environment as the adaptive ability is inherited, it being a genetic basis whereas fitness is the outcome of the ability to adapt and hence getting selected by nature, Two  key concepts of the Darwinian theory of evolution are branching descent and natural selection.