Speciation, Biology

Ernst Mayr, for whom, species and species problem have been the main concern of research, points out that speciation, the multiplication of species, that is division of one parent species into several daughter species is one process responsible for the evolutionary diversity of organic world. Darwin no where in his book Origin of Species defined the word species precisely although he interpreted speciation in terrns of reproductive isolation (Darwin again did not use the term reproductive isolation in his book.) Darwin did en~phasise that occupation of an unique ecological niche by each species could be a major characteristic of speciation. In this unit we shall briefly analyse the species concept laying emphasis on biological species and discuss in detail different types of mechanisms of speciation. Further we shall briefly look into how isolation brings about genetic repatterning and proceed to discuss the mechanisms of isolation with well chosen examples. As an illustration of how isolating mechanisms develop gradually, we shall explain the concept of ring species - the evolution of distinct new species. Finally there will also be a discussion on a phenomenon called genetic drift which however has no causal connection with speciation process but explains that in peripheral isolates gene frequencies drift due smapling error.

Posted Date: 4/5/2013 5:10:45 AM | Location : United States

Related Discussions:- Speciation, Assignment Help, Ask Question on Speciation, Get Answer, Expert's Help, Speciation Discussions

Write discussion on Speciation
Your posts are moderated
Related Questions
Q. Does glycolysis take place within the mitochondria? Glycolysis happens in the cytosol and not in the mitochondria. Pyruvic acid molecules later enter mitochondria to partici

Diarrhoeas disease: Diarrhoeas disease rank among  th most leading causes of children's death in developing countries. We shall discuss two main problems in this section i.e.

In chronic myelogenous leukemia, white blood cells proliferate ceaselessly. In affected white blood cells, the BCR-ABL oncogene, the result of a gene fusion, transmits a constitu

Q. Which are the target tissues and target organs of the neurohypophysis? The target organs of oxytocin are the mammary glands and the uterus and target organs of ADH are the k

The cystic fibrosis allele occurs in European populations with q=0.02, what fraction of this population can be expected to have cystic fibrosis?

Sexual Reproduction All metazoans, if or if not capable of propagating asexually, produce special cells termed as gametes. The gametes may be either male gametes or sperms or

What is lamarckism? Lamarckism is the theory that unites the law of use and disuse with the law of the transmission of acquired characteristics, i.e., that asserted that acquir

Q. Colony collapse disorder in honey bees? Honey bees (Apis mellifera) are social insects and live in colonies in hives. Honey bees were introduced from Europe to the USA to po

Yabapox Yabapox is a disease affecting mangabeys, rhesus, cynos, vervets, stumptails, and patas monkeys. It is caused by the Yaba-like disease virus (YLDV) and Yaba monkey tumor v

Define regulation of malice enzyme by starvation & refeeding? ME catalyzes the oxidative decarboxylation of malate to pyruvate and CO 2 simultaneously generating the reduced