Kerala SSLC Biology Chapter 8 Notes The Paths Traversed by Life English Medium
Earth originated first, followed by Later so many diverse organisms were formed on the earth. These facts fascinated human beings always. Though many arguments originated in course of time, most of them were discarded for want of evidences. Scientific enquiries are going on even today to collect more evidences to make explanations more logical.
→ The Panspermia theory and the theory of chemical evolution are theories related to the origin of life on earth and are discussed even today.
→ Acquired characters : The characters developed during the life time of organisms.
→ Darwin’s finches : The finches that led Charles Darwin to the theory of natural selection.
→ Charles Darwin presented his Natural selection theory on the origin of species by means of natural selection.
→ Thomas Robert Malthus An economist, influenced Darwin’s speculations about the diversity of the beaks of finches.
→ Neo Darwinism : Modified version of Darwinism revised in the light of new information from the branches of genetics, cytology, geology and paleontology.
→ Homologous organs : Organs that are similar in structure and perform different functions.
→ Fossils: Are the remnants of primitive organisms.
→ Anthropoidea : The category which included humans, chimpanzee, gorilla, orangutan, gibbon and monkeys.
→ Cercopithecoidea : The category in which monkeys are included.
→ Hominoidea : The category which included humans, chimpanzee, gorilla, orangutan and gibbon.