Essays on Speciation

The purpose of this paper is to review the article, “Was Darwin Wrong?”, by David Quammen (2004) and to offer some discussion at the end of the paper. The main thrust of the Quammen’s article is to provide a description of the current and past evidence that supports Darwin’s theory of evolution through natural selection. With a few exceptions, the title of the article is answered with a firm “no, Darwin was right.” Quammen first began with a discussion of the concept of theory and explained that a theory is an explanation for a set of circumstances ...

Introduction

The process of learning in animals and humans come through a series of situations that come together to motivate, and ignite the brains and enable them to repeat specific actions in the face of certain circumstances. The basic logic presented by psychologists and biologists is that there is intrinsic motivation based on the brain which controls the nerves and models of an animal or human being. This implies that an external variable triggers an extrinsic motivation that gets the organism to ignite the internal or intrinsic motivation in order to undertake certain actions and internalize it in order to ...

Different cultures have developed different mythologies and creation stories that try to explain the origin of humans. Similarly, scientists have established the processes of evolution that provide an explanation of the same. However, evolution is different from the mythologies and creation stories in which it is based on the scientific language. Another difference between the creation stories and evolution is that evolution is grounded in the ideas that can be tested. According to Chapter 2, Evolution can be termed as the scientific way to depict how the species appear and change over time. To provide a clear understanding of ...

Evolution is the scientific way of explaining how species come into existence and how they change over time. Evolution is also a mythology which explains the origin of human beings. Most of the evidence for evolution, which come as a result of historical and cultural processes contributes to scientific thought, hence making the scientists accept evolution as a fact. The process of evolution has many areas of discussion, for example, the four forces of evolution, the concepts of species and population, variation, isolation mechanisms, and speciation. This paper explains the concepts one by one in details. There were different ...

Nursing:

Purpose The aim of the lab was to investigate what happens when a natural physical barrier suddenly splits a species within a given population.

Introduction

A species is a group of organisms within a population that can interbreed under natural conditions to produce fertile and viable offspring (The University of Miami, n.d.). In this context, a species exhibits reproductive isolation, in which physical and behavioral traits allow them to reproduce only with organisms that possess similar traits (Howard & Berlocher, 1998). Speciation describes how new sets of species are created and occurs when a group of organisms within a species separates ...

Consequences of Assortative Mating in Humans

Assortative mating refers to whereby individuals having same genotype mate with each other to produce offsprings’. This changes the genotypic and allelic frequencies in a given population. It is sometimes due to the frequent intra-sexual competition within a population. There are several consequence of assortative mating. It results to homozygosity increase due to phase disequilibrium of gametes. Therefore, the gametes will have no differences. Another consequence is that the variance of the total population will also increase. Genetic effects in a given population are greatly influenced by the assortative mating degree. In a population where assortative mating has occurred, ...

Genetics Exercise

Directional selection entails natural selection favoring one phenotype causing its allele frequency to shift in one direction. The constant increase in frequency of the favored allele is independent of its dominance compared to other alleles; thus, even recessive alleles can ultimately become fixed. For instance, environment pressures and changes of diet affect the size (depth) of beaks of a population of cardinals in the subsequent generations. During the rainy spells, there is a huge supply of small seeds as compared to large seeds; therefore, the cardinals seldom ate large seeds and their beaks become shorter. Throughout the dry spells, neither the ...