This is a Most important question of gk exam. Question is: Branch of Biology deals with extinct organisms - , Options is: Palynology, 2. Phylogency, 3.
Portal:Extinct and endangered species
De-extinction , also called resurrection biology , the process of resurrecting species that have died out, or gone extinct. Although once considered a fanciful notion, the possibility of bringing extinct species back to life has been raised by advances in selective breeding, genetics , and reproductive cloning technologies. Key among those advances was the development in the s of a technique known as somatic cell nuclear transfer SCNT , which was used to produce the first mammalian clone , Dolly the sheep born , died In , using SCNT, scientists very nearly achieved de-extinction for the first time, attempting to bring back the extinct Pyrenean ibex or bucardo, Capra pyrenaica pyrenaica.
A clone was produced from preserved tissues, but it died from a severe lung defect within minutes of being born. The near success of the attempt sparked debate about whether species should be brought back from extinction and, if they are brought back, how it should be done and how the species should be managed. The candidate species for de-extinction are many. Some high-profile examples include the woolly mammoth Mammuthus primigenius , the passenger pigeon Ectopistes migratorius , the thylacine Thylacinus cynocephalus , and the gastric-brooding frog Rheobatrachus silus.
De-extinction does not extend to dinosaurs , partly because of the extreme old age of specimens and the severe degradation of DNA over time. The possibility of bringing extinct species back to life was first explored in the early 20th century, through an approach known as back breeding or breeding back. Back breeding, for the production of a breed that displays the traits of a wild ancestor, is based on the principles of selective breeding, which humans have used for centuries to develop animals with desired traits.
As a consequence, the resulting Heck cattle bore little resemblance to the aurochs. In the latter part of the 20th century, tools emerged that enabled scientists to isolate and analyze DNA from the bones, hair, and other tissues of dead animals. Coupled with advances in reproductive technologies such as in vitro fertilization , researchers were able to identify cattle that are close genetic relatives of the aurochs and combine their sperm and eggs to produce an animal the so-called tauros that is morphologically and genetically similar to the aurochs.
Other advances in genetic technologies have raised the possibility of inferring and reconstructing the genetic sequences of extinct species from even poorly preserved or cryopreserved specimens. Reconstructed sequences could be compared against the sequences of extant species, allowing for the identification of not only living species or breeds best suited for back breeding but also genes that would be candidates for editing in living species.
The discovery of CRISPR c lustered r egularly i nterspaced s hort p alindromic r epeats , a naturally occurring enzyme system that edits DNA in certain microorganisms, greatly facilitated the refinement of genome editing for de-extinction. Cloning for de-extinction has centred primarily on the use of SCNT. SCNT entails the transfer of the nucleus from a somatic body cell of the animal to be cloned into the cytoplasm of an enucleated donor egg an egg cell that came from another animal and that has had its own nucleus removed.
The egg cell is stimulated in the laboratory to initiate cell division , leading to the formation of an embryo. The embryo is then transplanted into the uterus of a surrogate mother, which in the case of de-extinction is a species closely related to the one that is being cloned. In the attempt to resurrect the extinct Pyrenean ibex in , researchers transferred nuclei from thawed fibroblasts of cryopreserved skin specimens into enucleated eggs of domestic goats.
It may also be possible to use stem cells to resurrect extinct species. Somatic cells can be reprogrammed through the introduction of specific genes, creating so-called induced pluripotent stem iPS cells. Such cells can be stimulated to differentiate into different cell types, including sperm and eggs that potentially can give rise to living organisms. Similar to the other techniques of de-extinction, however, the success of an approach based on stem cells depends largely on the quality of DNA that is available in preserved specimens.
Cloning, stem cell manipulation, genome reconstruction, and genome editing are powerful technologies with significant ethical ramifications when applied to de-extinction. The expense and inefficiency of SCNT, for example, has raised questions about its practicality for resurrecting extinct species. Perhaps the greatest concern, however, is the potential of those technologies, as well as back breeding, to alter the course of natural history.
De-extinction provides an opportunity for humans to rectify past harms inflicted on other species, as well as to expand species diversity. But many extinct species were driven out of existence as a result of habitat loss, and others lived in habitats that have since been altered dramatically. In addition, in the near term, resurrected species would be considered endangered and would therefore require conservation , for which resources often are constrained or lacking. De-extinction, by providing the option to bring species back later, also could have the unintended consequence of condoning extinction and could give impetus to endeavours that threaten biodiversity.
Other concerns include unknowns about the fate of resurrected animals, from the health of cloned individuals to whether the animals would be able to adapt to current environmental conditions and whether they would be able to produce viable offspring. The potential to be leveraged as a means of advancing financial and commercial interests has led some to question the motivation of researchers and companies behind certain de-extinction projects. Nonetheless, de-extinction has helped fuel important progress in science, building particularly on knowledge in developmental biology and genetics.
It also has generated interest in endangered species , with many of the tools of de-extinction also being applicable to conservation of endangered species. The reconstruction of extinct genes could be used, for example, to restore genetic diversity in threatened species or subspecies. We welcome suggested improvements to any of our articles. You can make it easier for us to review and, hopefully, publish your contribution by keeping a few points in mind.
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Written By: Kara Rogers. See Article History. Learn More in these related Britannica articles: See also de-extinction. The sequencing of the dodo genome by geneticists in reinvigorated this discussion as well as the ethical debate of using de-extinction techniques to alter natural history. Genetics , study of heredity in general and of genes in particular. Genetics forms one of the central pillars of biology and overlaps with many other areas, such as agriculture, medicine, and biotechnology.
Cloning , the process of generating a genetically identical copy of a cell or an organism. Cloning happens all the time in nature—for example, when a cell replicates itself asexually without any genetic alteration or recombination. Prokaryotic organisms organisms lacking a cell nucleus such as bacteria create genetically identical duplicates of…. Somatic cell nuclear transfer SCNT , technique in which the nucleus of a somatic body cell is transferred to the cytoplasm of an enucleated egg an egg that has had its own nucleus removed.
Introduction The tools of species resurrection Ethical considerations. Edit Mode. Tips For Editing. You may find it helpful to search within the site to see how similar or related subjects are covered. Any text you add should be original, not copied from other sources. At the bottom of the article, feel free to list any sources that support your changes, so that we can fully understand their context.
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million-year-old fossils show how extinct organisms attacked their prey
Extinction , in biology , the dying out or extermination of a species. Extinction occurs when species are diminished because of environmental forces habitat fragmentation, global change, natural disaster, overexploitation of species for human use or because of evolutionary changes in their members genetic inbreeding , poor reproduction , decline in population numbers. Rates of extinction vary widely. For example, during the last , years of the Pleistocene Epoch about 2.
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In biology , extinction is the termination of an organism or of a group of organisms taxon , usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa , where a species presumed extinct abruptly "reappears" typically in the fossil record after a period of apparent absence. More than 99 percent of all species, amounting to over five billion species, that ever lived on Earth are estimated to have died out. Estimates on the number of Earth s current species range from 10 million to 14 million, of which about 1.
Branch of Biology deals with extinct organisms -
More than 90 percent of all organisms that have ever lived on Earth are extinct. Learn what may cause animal die-offs. As new species evolve to fit ever changing ecological niches, older species fade away. But the rate of extinction is far from constant. At least a handful of times in the last million years, 50 to more than 90 percent of all species on Earth have disappeared in a geological blink of the eye. Though these mass extinctions are deadly events, they open up the planet for new life-forms to emerge. Dinosaurs appeared after one of the biggest mass extinction events on Earth, the Permian-Triassic extinction about million years ago.
Should we bring extinct species back from the dead?
But no amount of trickery will stop the inevitability of death. Death is the inescapable endpoint of life. And this is as true for species as it is for individuals. Estimates suggest All species that exist today — including human beings — will invariably go extinct at some point. For example, researchers have identified the Big Five mass extinctions: Unfortunately, we are also now getting a good firsthand view of what extinction looks like, with the rapid increase in extinction rates over the last century. But what factors make any one species more or less vulnerable to extinction? The rate of extinction varies between different groups of animals and over time, so clearly not all species are equally susceptible.
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De-extinction , also called resurrection biology , the process of resurrecting species that have died out, or gone extinct. Although once considered a fanciful notion, the possibility of bringing extinct species back to life has been raised by advances in selective breeding, genetics , and reproductive cloning technologies. Key among those advances was the development in the s of a technique known as somatic cell nuclear transfer SCNT , which was used to produce the first mammalian clone , Dolly the sheep born , died In , using SCNT, scientists very nearly achieved de-extinction for the first time, attempting to bring back the extinct Pyrenean ibex or bucardo, Capra pyrenaica pyrenaica. A clone was produced from preserved tissues, but it died from a severe lung defect within minutes of being born.
What Makes Some Species More Likely to Go Extinct?
The scope of biology is enormous - it s the history of all living organisms and their role on earth. There are many branches of biology, each focused on different aspects of research. Biology is first split into 3 main branches that focus on 3 different organisms: Zoology animals , botany p … lants , and microbiolog y organisms. More information on each branch as well as numerous sub-branches are listed below in alphabetical order. Branches of Biology. Agriculture - the science and practice of producing crops and livestock from the natural resources of the earth. Anatomy - the study of the animal form, particularly the human body. Astrobiology - the branch of biology concerned with the effects of outer space on living organisms and the search for extraterrestrial life. Biochemistry - the chemical processes in all living organisms and the study of the structure and function of cellular components, such as proteins, carbohydrates, lipids, nucleic acids, and other biomolecules, and of their functions and transformations during life processes.
Biology is the natural science that studies life and living organisms , including their physical structure , chemical processes , molecular interactions , physiological mechanisms , development and evolution. Biology recognizes the cell as the basic unit of life, genes as the basic unit of heredity , and evolution as the engine that propels the creation and extinction of species. Living organisms are open systems that survive by transforming energy and decreasing their local entropy  to maintain a stable and vital condition defined as homeostasis. Sub-disciplines of biology are defined by the research methods employed and the kind of system studied: It was used again in in a work entitled Philosophiae naturalis sive physicae: The first German use, Biologie , was in a translation of Linnaeus work. The term came into its modern usage with the six-volume treatise Biologie, oder Philosophie der lebenden Natur —22 by Gottfried Reinhold Treviranus , who announced: Although modern biology is a relatively recent development, sciences related to and included within it have been studied since ancient times.
Exhilarating because of the unprecedented opportunities to understand life and boost conservation efforts, but terrifying in part for its ethical quandaries. In her recent book How to Clone a Mammoth:
February 17, The Cambrian Period, which occurred between million and million years ago, is an important point in evolutionary history where most of the major groups of animals first appear in the fossil record. Often called the "Cambrian explosion," fossils from this time provide glimpses into evolutionary history as the world s ecosystems were rapidly diversifying. Most fossils preserve the physical remains of organisms and their structure; however, geologists and paleobiologists at the University of Missouri recently collaborated to study fossils that reveal the behaviors of predators preserved as traces in ancient sediments. Thus, fossils from southeast Missouri are helping scientists unlock clues about the behaviors of these predators and their interactions with their prey. Evidence shows that these ancient organisms were behaviorally sophisticated, tailoring their attacks for effectiveness. Trilobites are a fossil group of extinct marine invertebrate animals with external skeletons see photo. As predators and scavengers, they flourished in the Cambrian period and were very prominent in the oceans that once were located in Missouri. In that time, I ve run across thousands of fossilized trilobite burrows. It is rare that we get to study the activities of million-year-old organisms, yet the fossils in this locality are helping us determine how these organisms behaved. The field area near the mountains is home to an abundance of trilobite trace and body fossils. James Schiffbauer and John Huntley, both assistant professors of geological sciences in the MU College of Arts and Science, worked with Shelton and Tara Selly, a graduate student in Schiffbauer s research group, to collect slabs of rocks from the site. Selly, then analyzed them in the lab at MU. Using sophisticated three-dimensional laser scanning and digital photograph analyses, sections of the rocks revealed burrows or trails left behind by trilobites and their prey—often worm-like creatures—in ocean sediments. To the scientists, these intersecting trails show how the predators caught their prey.
Earth is in the midst of its sixth mass extinction: Somewhere between 30 and species disappear every day, thanks largely to humans, and more than types of mammals, birds, reptiles, and amphibians have vanished since Indeed, earlier this month, ecologists at the University of California, Santa Barbara UCSB , published guidelines for how to choose which species to revive if we want to do the most good for our planet s ecosystems. The two animals at the forefront of this discussion are the woolly mammoth , a hairy, close relative of the elephant that lived in the Arctic, and the passenger pigeon , a small, gray bird with a pinkish red breast once extremely common in North America. The last mammoths died about years ago, and the passenger pigeon vanished around As cool as it might be to visit a zoo filled with woolly mammoths, saber-toothed tigers, and giant tortoises, the best reasons for bringing back extinct animals have more to do with ecology than tourism. Every animal in an ecosystem has a function:
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