Reproduction is arguably the most important aspect of life as we know it. Through reproduction, living organisms have been able to multiply and sustain themselves on earth. It is important to note that there are diversified forms of reproduction based on the types of living organisms which have been effectively categorized. For example, the reproduction processes in mammals is quite different to that of birds and reptiles to mention a few. Reproduction has also played a significant role in helping scientists identify organisms based on their reproductive habits and characteristics (Cothran 338). Reproduction therefore is a very important process which has facilitated the survival and longevity of the existence of species. One theory that has revolutionized the manner in which scientist view development and progress in the life of organisms is evolution. A theory initiated by Charles Darwin, evolution has proven concrete and reliable in elaborating on quite a number of biological …show more content…
Viviparity is believed to have emanated or rather evolved from early conditions of lecithotrophy and oviparity (Maryoung et al 707). Lecuthotrophy basically refers to the reproduction process where nutrients are provided to embryos through the yolk. There are various techniques both modern and traditional that have been applied in effectively analyzing the evolution of viviparity among animals. One such hypothesis is through the analysis of the sequence taken by viviparity leading to its characterization as a linear model. Through this model, it is believed that the egg in question might have stayed for longer periods within the reproductive tract of the parent. This speculation or rather theoretical conclusion is based on the assumption that that fertilization occurred internally within the female parent’s body (Maryoung et al
The experiment can be improved by counting the number of eggs each gravid Artemia carries and the number of successfully born offspring to further support the hypothesis that the females fed on high nutrition have higher fecundity compared to the ones treated with low nutrition.
Evolution, also known as descent with modification, is a phrase Darwin used in proposing the evolution of Earth’s many species. Charles Darwin noticed that the descendants of ancestral species were different from the present day forms of species. Darwinism is a theory of biological evolution developed by Charles Darwin who was an English naturalist. He expounded the theory of evolution in his book of the Origin Species in 1859. He expresses that all types of organisms emerge and develop through natural selection, small, acquired traits that expands the individuals of capacity, survival, and reproduction. In this book, Darwin theorized that animals and plants evolve and develop with the aid of the creator through the process of natural selection.
The word “monotreme” is Greek for “one-hole,” referring to the cloaca that is the exit for the urinary, reproductive, and excretory systems (Dawson, 1983). The creatures are oviparous--the females lay eggs that develop outside of her body. This paper will explain the background of the animals, the anatomy of the tract and egg, breeding behavior, and genetics behind this unique reproductive system. It will pay special attention to the similarities of the monotreme reproductive system to those of animals we are more familiar with.
Social reproduction is the reproduction of cultural, human, and social capital in society. Therefore languages, traditions, cultural values, education, food security, and social circles are passed down from one generation to the next through Karl Mannheim’s concept of “fresh contact” and through society as a whole. Social reproduction is effective when social structures and equality within society are maintained. Inequality, poverty, and social changes that force society to adapt can impede the process of social reproduction causing what is known as a “crisis in social reproduction” (Wells, 2009). Born into Brothels demonstrates a crisis of social reproduction that negatively impacts the lives of children living in Sonagachi as a result of globalization, neoliberal policies, poverty, lack of adequate education and social structures to pass down capital, and the stigma of prostitution. Additionally, it shows the need for children to make economic contributions to their families that prevent them from leaving the brothel.
Anyone with even a moderate background in science has heard of Charles Darwin and his theory of evolution. Since the publishing of his book On the Origin of Species by Means of Natural Selection in 1859, Darwin’s ideas have been debated by everyone from scientists to theologians to ordinary lay-people. Today, though there is still severe opposition, evolution is regarded as fact by most of the scientific community and Darwin’s book remains one of the most influential ever written.
The traditional explication for the maintenance of sex was that the process of meiosis and fertilization engender genetic variation on which natural cull can act.
Evolution is the heart of life. Without it, life could not be sustainable. When the environment changes and the species within the environment fails to adapt or change, then all living organisms would perish over time. Charles Darwin, a biologist and naturalist, is known worldwide for his contributions to science for the extensive research and experiments conducted to help support the theory of evolution and how it worked. One basic mechanism that can be used to understand evolution is natural selection. “Resources are limited in nature, organisms with heritable traits that favor survival and reproduction will tend to leave more offspring than their peers, causing the traits to increase in frequency over generations.” (Darwin, Evolution,
The battle between sexual and asexual reproduction is a competition that has been ongoing for millions of years. Somewhere along the way due to its higher level of genetic variation, sexual reproduction was able to overcome the two fold advantage of asexual reproduction, and now dominates reproduction in organisms. However, some types of organisms such as worms and corals have acquired the ability to reproduce both sexually and asexually. The purpose of this paper is to explore the differences in asexual and sexual reproduction both from a biological and an evolutionary standpoint and to explain why evolution has made it possible for soft corals to reproduce both sexually and asexually.
The Female reproduction cycle includes seven key parts; FSH, LH, estrogen progesterone, ovulation, menstruation and pregnancy. When fertilization occurs, the egg will begin to divide through mitosis. After several divisions a cluster of cells surrounding the embryo, called a blastocyst implantation .Where they attach to the uterine wall by the secretion of enzymes. Within a few days of this process the uterus will continually divide , the embryo; Releasing hormones to keep the corpus luteum functioning for a few weeks to allow nourishment and protection to reach and line the uterus. Then membrane like chorionic villi are formed to help with protection. These form an essential organ called the placenta; the connection between mother and embryo. This serves as the embryo’s main source of nourishment.
The merger of two germinal cells, one being a sperm cell and the other being an egg cell, is complete within twelve hours, at which time the egg is fertilized and becomes a zygote containing forty six chromosomes required to create a new human life. It is during this remarkable process when conception occurs. Conception confirms life and makes that undeveloped human one of a kind (Rorvik & Shettles, 1983, p. 16). Many researchers, as well as scientists, identify the first moments of life as the instant when a sperm cell unites with an ovum, o...
The reproductive system is the part of the human body that is necessary to continue the human existent. Reproduction in humans normally would begin by a male and female having sexual intercourse with each other.
The evolutionary theory is the concept that species evolve over time through the mechanism of natural selection of survival and reproduction. Natural selection means acting on the assumption that various living organisms were produced by genetic diversity and mutation. The evolution theory may also be referred to as the philosophizing science. This theory states that all phenomena are derived from natural causes and can be explained by scientific laws without reference to a plan or purpose.
Evolution is a complex process by which organisms change over time; it is a process in which traits are passed from one generation to the next (Darwin and Beer 1996:108-139). Evolutionists have tried to explain the loss of functions of different organs, for centuries. The two most prominent scientists that studied evolution were Jean-Baptist Lamarck and Charles Darwin. Lamarck’s theory of inheritance of acquired characters and Darwin’s variational evolution were the most important theories that attempted to explain evolution before the discovery of genes during the beginning of the twentieth century.
Charles Darwin, the English naturalist and geologist is attributed and accredited for his theory of evolution. His theory of evolution is based on the premise that strong heritable traits help individuals to survive in adverse and inimical environments.