IAS Zoology

Online guidance for the students of Zoology

All Academic content is by Dr. Girish Chandra, PhD (unless otherwise stated), ex Professor, Delhi University

  • Burst of evolution takes place when animals are put into new environment.
  • Nothing in biology makes sense except in the light of evolutionT. Dobzhansky
  • Contrary to Darwinism, reproduction and not survival is at the centre of evolutionary process.
  • Batrachotoxin, the poison from the skin of South American tree frogs, Phyllobates and Dendrobates, is the most toxic animal secretion known to mankind. Only 200 microgram of it is enough to kill a man.
  • Natural selection requires genetic variations but natural selection also reduces genetic variations by eliminating alleles. Thus evolution by natural selection bites the hand that feeds it.
  • In humans there are at least 4500 genes that cause diseases.
  • The combined length of blood capillaries in human body is about 96,500 kms. If blood has to fill all these capillaries, no blood will be left in arteries and veins. Therefore, body selectively supplies blood to organs that need it most.
  • Natural selection refines and specializes a species to live in its environment but the same specializaion brings its doom when the environment changes. Thus the species also follow the cycle of birth, growth and death.
  • Although chimpanzee genome differs from human genome by hardly 1.5%, yet there have been 40 million evolutionary events that separated chimps from us. Read on the Riddle of Human Origin
  • Biological evolution tracks opportunities but is blind to destinations other than survival – Strickburger. Read on different Ways of Evolution
  • Natural selection causes a change in gene frequency but is not the same as a change in gene frequency. Read details in Hardy-Weinberg’s Law

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