Evolutionary Biology Definitions Essay

Submitted By CarleyBoo
Words: 727
Pages: 3
Open Document
1. Evolution is a change in the genes of a population over time. A gene is a unit that can be inherited and can be passed on unaltered for many, many generations. A gene pool is a set of all genes in a species of population. Evolution has many meanings. All organisms are linked via descent to a common ancestor is often called evolution. Evolution could also be the theory of how the fist living things appeared on earth.
2. Evolution requires genetic variation. Variation in alleles of genes occurs both within and among populations. Genetic variation is important because it provides the genetic material for natural selection. Genetic variation is brought about by mutation, which is a permanent change in the chemical structure of a gene. Polyploidy is an example of chromosomal mutation. Polyploidy is a condition wherein organisms have three or more sets of genetic variation
3. Natural selection is the gradual, non-random process by which biological traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution. Charles Darwin who intended it to be compared with artificial selection, which is now called selective breeding, popularized the term “natural selection.
4. Genetic drift or allelic drift is change in the frequency of a gene variant in a population due to random sampling. The alleles in the offspring are samples of those in their parents, and chance has a role in determining whether a given individual survives and reproduces. A population's allele frequency is the fraction of the copies of one gene that share a particular form. Genetic drift may cause gene variants to disappear completely.
5. Recombination can be thought of as gene shuffling. Most organisms have linear chromosomes and their genes lie at specific location (loci) along them. Bacteria have circular chromosomes. In most sexually reproducing organisms, there are two of each chromosome type in every cell. For instance in humans, every chromosome is paired, one inherited from the mother, the other inherited from the father. When an organism produces gametes, the gametes end up with only one of each chromosome per cell. Haploid gametes are produced from diploid cells by a process called meiosis.
6. Evolution is a change in the gene pool of a population over time; it can occur due to several factors. Three mechanisms add new alleles to the gene pool: mutation, recombination and gene flow. Two mechanisms remove alleles, genetic drift and natural selection. Except in rare cases of high gene flow, new alleles enter the gene pool as a single copy. The fate of any new allele depends a great deal on the organism it appears in. This allele will be linked to the other alleles near it for many generations. The effects of selection and drift are coupled. Drift is intensified as selection pressures increase. This is
Show More

Related Documents: Evolutionary Biology Definitions Essay

chapet 10 vocab for bio Essay

during geological history have resulted from the action of continuous and uniform processes. 7. Variation, in biology, any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences 8. Adaptation, in biology, process by which an animal or plant species becomes fitted to its environment; it is the result of natural selection's acting upon…

Words 488 - Pages 2

AP Biology Paper

Part I. Introduction Chapter 1. What is Human Ecology? Chapter 2. Environment, Technology, and Culture What Is Human Ecology? 1 Chapter 1. WHAT IS HUMAN ECOLOGY? Another Unique Species (Title of Robert Foley’s 1987 book on evolutionary human ecology) I. Introduction What is human ecology? Human ecology is an approach to the study of human behavior marked by two committments. First, human ecologists think that humans should be studied living systems operating in complex environments…

Words 7920 - Pages 32

Evolution and Azt Essays

Evolution The central theory of biology Most influential on all aspect of biological research “Nothing makes sense in biology except in the light of evolution” T. Dobzhanski (1900-1975) Main Concepts Natural Selection Movement of Alleles in pops. And between generations Tree thinking Trade-offs “Evolution in Five Stories” HIV – an evolutionary case studies The evolution of sex The 'Dover trial’ What makes mammals mammals? Human evolution Peppered Moth Genetics…

Words 629 - Pages 3

Race And Gender Analysis

questions by looking at the relationship between human behaviour and biology, as well…

Words 940 - Pages 4

Developmental Biology and bilaterally Symmetrical Animals Essays

Animal Diversity The definition of Cephalization is the development of the head. Paedomorphsis and cephalization It is the tendency for sensory, neural, and feeding organs to be concentrated at the front end of the body, leading to the development of a head during both evolution and embryological development. It is considered an evolutionary trend whereby nervous tissue, over many generations, becomes concentrated toward one end of the organism. This process eventually produces a head region…

Words 863 - Pages 4

Chapter 1: What Is Biology? Essay

NOTES FOR BIOLOGY 1001 SECTION 001 Fall 2012 DR. STEVEN POMARICO, INSTRUCTOR CHAPTER 1 AN INTRODUCTION TO LIFE ON EARTH What is Biology? --- The science of living organisms and life processes. O.K., so what is science? And If biology is the science of “life,” what exactly is life? We all recognize what life is, but it’s difficult to define. The characteristics of life: 1) -Complex, organized structure 2) -Homeostasis - the ability to maintain the structure…

Words 805 - Pages 4

Evolution: Biology and Perfection Essay

the complicated literary definition given to this word. Exact and flawless are some common synonyms of the word perfect. Perfection is something that has reached the pinnacle, the zenith of existence. Nothing which is perfect needs any alterations, modifications or changes. When something is perfect it exists with ease. It does not struggle to remain where it is, and it does not struggle to remain alive; it works in harmony with its environment. Going beyond the definition, something that is perfect…

Words 1819 - Pages 8

Analysis of Arguments Against Id Essay

the fact that scientific theories must be falsifiable, and his second premise deals with the false dichotomy of evolution and intelligent design. While his arguments are logically valid, an objection that could be made about his argument is his definition of intelligent design. One of the premises of Ayala’s argument is that for a theory to be scientific, it must be falsifiable. Since intelligent design proponents tell us that we cannot know the mind of a designer, intelligent design is untestable…

Words 972 - Pages 4

Faulty Wiring Essay

aggressive behavior and beyond the control of the individual. This essay analyzes several causes of sudden violent aggression which result in mass death and injury from the biological perspective. Definition According to Coon (2013), aggression refers to “any action carried out with the intention of harming another person and the human capacity for aggression is staggering.” (p.584). In fact, statistics showed over 58 million people died since World…

Words 1712 - Pages 7

Research skills Essay

permission from the National Academies Press. Teaching About Evolution and the Nature of Science http://www.nap.edu/catalog/5787.html 1 Why Teach Evolution? W hy is it so important to teach evolution? After all, many questions in biology can be answered without mentioning evolution: How do birds fly? How can certain plants grow in the desert? Why do children resemble their parents? Each of these questions has an immediate answer involving aerodynamics, the storage and use of water…

Words 4822 - Pages 20