THE THEORY OF EVOLUTION BY NATURAL SELECTION
abidaDarwin returned to England in 1836. For the next 17 years, Darwin worked on the notes and specimens collected during his voyage. He made new observations. Artificial selection: He was…
THE HARDY-WEINBERG THEOREM
rubabEnglish mathematician Godfrey II. Hardy and German physician Wilhelm Weinberg independently derived a mathematical model in 1908. This model explains what happens to the frequency of alleles in a population…
THE MODERN SYNTHESIS
The combination of the principles of population genetics and Darwinian evolutionary theory is called modern synthesis. Modern synthesis comes from the study of genetics. It explains why variations exist among…
DEFINITIONS AND KEY POINTS FOR ECOPHYSIOLOGY
sanaTERMS DEFINITIONS Heliophytes The plants which grow best in full sunlight are called heliophytes. Sciophytes The plants which grow best at lower light intensities are called sciophytes. Facultative Seiophytes…
EVIDENCE OF EVOLUTION
Evidences from Biogeography The study at the geographic distribution of plants and animals is called biogeography. Biogeographers explain the reason of distribution of organisms in different regions. Biogeographic studies show…
EARLY DEVELOPMENT OF DARWIN’S IDEAS OF EVOLUTION
Darwin started his work on his theory of natural selection. It was a long hardworking process. Darwin wanted to convince him that change occurs over time. Darwin accepted the opinion…
Multiple Choice And Fill in The Blankd OF MORPHOLOGY
sidraMultiple Choice Questions (MCQs) The inflorescence in which main axis is elongated and bears sessile lateral flowers is called: (a) Spike (b) Corymb (c) Spikelet (d) Catkin The spike with…
WIND
Air in motion is called wind. It can circulate gases, water vapours and small soil particles. The action of wind is an ecological factor. Its affect may be direct or…
WATER
Water is a most important environmental factor. It is essential for all life processes. The living cells have about 80% water. It is essential for the maintenance of turgidity of…
DARWINISM
Charles Robert Darwin (1809— 1882) was born on February 11 1809. His lather as a physician. Dan' in collected dogs and hunting birds during his youth. These activities reduced his…