During the course of the past thirty years, the study of model organisms has become more significant in the study of embryological development. A model organism is a species that is easy to cultivate and monitor in a laboratory environment and is used to represent broad groups of organisms. Examples of successful and important model organisms include the Ascidia, Zebrafish, and Medeka species. Through intense researching of these organisms, scientists have been able to gain valuable insight into the developmental processes of many complex vertebrates, including humans.
Model organisms are used to study embryonic development for several reasons. These organisms have shared characteristics including short life spans and generation intervals, rapid development, and easily distinguished embryos, which make them ideal experimental targets. Through the mapping of developmental processes and similarities between the model organisms and other major vertebrate groups have been discovered, the model organisms serve to represent numerous complex organisms. Also, research involving the model organisms has allowed scientists to gain a better understanding of developmental processes and functions (Anderson and Ingham 1003).
Since 1871, ascidians, or sea squirts, which are simple invertebrate chordates, have been used as model organisms to study embryonic development. The ascidia embryo represents an ideal model for vertebrate development because it has the same basic developmental and morphologic features of vertebrates. Furthermore, as a less complex organism, the ascidians have only a few hundred cells rather than the thousands of cells found in most vertebrates. The ascidia species was also chosen as a model organism because it has a...
... middle of paper ...
...mportant common genes for eye development (Wittbrodt et al. 2002).
Through the use of model organisms, scientists have been able to understand complex processes of embryonic development much better. By using organisms that are smaller, simpler, and easier to observe in a laboratory situation, scientists have made notable achievements in understanding the origins of tissues, organs, and various systems involved in the growth of vertebrates. Model organisms such as the ascidian, zebrafish, and medaka species have each proven important in scientists' study of vertebrate development. Furthermore, the understanding of these processes and the genes involved will likely have medical applications in the future. With a better understanding of the formation and functioning of organs and systems, scientists could find more effective ways to recognize and treat diseases.
Fox, R. 2001. Invertebrate Anatomy OnLine: Artemia Franciscana. Lander University. http://webs.lander.edu/rsfox/invertebrates/artemia.html, retrieved February 13, 2011.
STATEMENT OF USE: “Although many key questions can still only be answered by animal studies, non-animal methods now account for 90% of medical research and include mathematical and computer models, advanced tissue and cell cultures, and scanning technology.” This information will take a great stance in my paper once more research is done about it. Animals do not need to be used to understand biomedical medicine and knowledge. They are not models for anything society taunts them to be. (76
Parthenogenesis is a process of generating human embryos from only eggs put therapeutic cloning within reach
The zebra fish is commonly used for studies involving human diseases. (7). The zebra fish, has a very common genome in relation to humans and serves as a great tool of research for many human diseases. 300 million years separate the zebra fish and the humans last known common ancestor. Shockingly enough their genome is still a great resource for cancer research and many other genetic diseases due to their vast genomic similarities (1). The zebra fish is a model organism in many disease studies such as, cancer, human genetic diseases, neurological disease, Alzheimer’s and many more(8).
In the mid 1960's, R. G. Edwards and colleagues at Cambridge University began studying differentiation of rabbit embryonic cells in an artificial environment. They manipulated these embryonic cells into specific types of form such as connective tissue and muscle neurons.
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.
The relationship between disability and biomedical model is very complex; to understand the concept one needs to understand the biomedical model and the definition of disability. disability is a term that describes a person’s inability to perform daily activities. Biomedical model states that a disability is caused by a disease, disorder, mental or physical condition that deprives a person of the basic necessity of life. Furthermore, the medical model views a disabled person as functionally limited as it defines the norms for human functioning. From these two definitions, it can be concluded that both disability and the medical model are interlinked in ways of how a person’s inability to function have an impact in the interaction of society.
“Humans and sharks both have four gill arches as embryos, but the germ layers and arches develop into unrelated structures in each organism.” I do agree with the first part of this statement because it is true. The second part does not make much sense. The germ layers and arches do develop into related structure in each organism. I do not have a quote for this one but on page 91 Shubin shows a diagram on how a shark and human embryo form. Though they do not look the same in the beginning they still look the same in the end. Therefore developing into a related structure during the embryonic stages.
Figure 4.2 (left): 10X magnification light microscope image of a late gestation period mouse embryo, stained with Haematoxylin/Eosin and Alcian Blue.
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.
Looking at Physical Development it can be seen if the process of genes and environment operating together influence development. As the environment is constantly changing humankind needs to have changeable characteristics, some of which are physical, this is known as “Developmental Plasticity”. Piaget studied water snails and found that shape of the snails shell varied depending on its habitat. Pond snails had longer shells than lake snails who had shorter shells to suit the water turbulence. Suggesting that cells have the properties to change and become “self-organising”, cells can change the way they are developing in response to environmental stimuli. It is argued that genes can be switched “on” or “off” in response to this environmental stimuli and can alter the characteristics they produce.
Lauritzen, Paul. Cloning and the Future of Human Embryo Research. Oxford: Oxford UP, 2001. Google Books. Web. 12 Feb. 2014. source 12 (google books)
Evolutionary developmental biology (evo-devo) was instituted in the early 1980s as a distinctive field of study to characterise the new synthesis of evolution hypothesis (Müller, 2007). Evo-devo is regarded as a new rule in evolutionary biology and a complement to neo-Darwinian theories. It has formed from the combination of molecular developmental biology and evolutionary molecular genetics; their integration has helped greatly to understand both of these fields. Evo-devo as a discipline has been exploring the role of the process of individual development and the changes in evolutionary phenotype, meaning the developmental procedure by which single-celled zygotes grow to be multicellular organisms. Alterations in the developmental program frequently cause differences in adult morphology. When these alterations are helpful, they grow to be fixed in a population and can result in the evolution of new phyla. Evo-devo seeks to figure out how new groups happen by understanding how the method of development has evolved in different lineages. In other word, evo-devo explains the interaction between phenotype and genotype (Hall, 2007). Explanation of morphological novelty of evolutionary origins is one of the middle challenges in current evolutionary biology, and is intertwined with energetic discussion regarding how to connect developmental biology to standard perspectives from the theory of evolution (Laubichler, 2010). A large amount of theoretical and experiential effort is being devoted to novelties that have challenged biologists for more than one hundred years, for instance, the basis of fins in fish, the fin-to-limb change and the evolution of feathers. The biology of development promises to formulate a main contribution to these...
After Bonnet’s aphids gave birth to ninety-five offspring through parthenogenesis, Bonnet wrote to Réaumur of his success. Réaumur then read Bonnet’s letter to the French Academy of Sciences leading to Bonnet being officially named a correspondent in the experiment (Lawrence). Bonnet’s experiments were then repeated and refined by multiple biologists throughout the rest of the eighteenth century. However, progress came slowly. The first significant discovery of parthenogenesis in vertebrates did not occur until the 1950’s when scientists observed the process in certain strains of turkeys. Later, in the 1990’s, scientists observed parthenogenic tendencies in crustaceans such as brine shrimp. Unfortunately, neither of these species were able to reproduce by parthenogenesis in labs (Booth). After this monumental observation, biologists began to investigate the natural process of parthenogenesis in vertebrates living in the wild. The scientists specifically searched for a species that primarily reproduced by parthenogenesis, in an attempt to successfully replicate the process in labs. Through this research, it is now known that snakes,
First, cloning has a long history dating back thousands of years, which has allowed the process of cloning to evolve to more complex organisms. Cloning was first experimented with different plant offspring (“Cloning” n.p.). The cloning process of plants in the past was very simple and only required parts of the plant such as roots, stems, and leaves to be cut and planted, which would grow into an exact copy of the initial plant (“Cloning” n.p.). In the 1950s, scientists were able to successfully clone frogs in a more complex manner by transferring the nucleus from a tadpole cell to a frog egg that had already had its nucleus (“Cloning” n.p.). Scientists later discovered that their cloning procedure was a success when the frog that grew from the egg experimented on had the same genetic makeup as the tadpole that donated a nucleus from one of its cells (“Cloning” n.p.). Dolly the sheep is the product of the first successful cloning of a mammal (“Cloning” n.p.). “In 1997 Scottish scientist Ian Wilmut and his colleagues announced the birth of a clone of an adult mammal” (“Cloning” n.p.). Dolly was created from a cell of a breast gland from an adult sheep was put in an embryo and placed inside a sheep able to give birth (“Cloning” n.p.). Dolly was born looking identical to the shee...