Advantages:

      Disadvantages:

Dialogue: 
I think de-extinction can be a very powerful tool but it is a double-edged sword. It can be used to revive mammoths that would compact the permafrost and prevent it from melting easily. It can also be discovered cures for diseases by studying revived animals or stopping danger of extinction by reviving species. But, it would modify the ecosystem and destabilize it, which could result in terrible catastrophes extinguishing other species massively.  

Summary:
De-extinction is the process of creating an organism that is or resembles as extinct. And there 4 ways written in this page to do so. The first one is cloning, the most effective on copying the original species. It is done by extracting the nucleus of a cell conserved from the extinct species and introducing it into an egg without nucleus from the most similar species alive. The second one is genome editing which uses the system of CRISPR/Cas, concretely CRISPR/Cas9. When DNA is inserted into an organism and it is incorporated in specific zones of the organism's chromosomes, those regions are known as CRISPR. And then the organism's chromosomes gets transcribed into its RNA and Cas9 (a protein) binds to it. Then, Cas9 detects and  cuts DNA. This is very useful because it allows genome editing. The third one is back breeding, one of the least accurate when trying to get the original animal if not the most. It consists of breeding similar animals to get ancestral traits from one them. By doing this dozens with different traits from different existing animals it can be obtained an animal really close to the extinct one. This method depends on the ancestral trait still being in nowadays species. And the last one is iterative evolution. This last one consists of giving an existing animal (similar to the extinguished one) the same conditions the extinguished animal had when evolved for them to evolve into an exemplar very similar to the original. 
Some advantages of de-extinction are that species in danger of extinction or species recently extinguished species can be preserved. Revived species can be studied to get cures for diseases. Revived species can be used as a "flagship" to attract people to donate for conservation of species and ecosystems. And some species can be introduced to help the imbalances of the ecosystem such as mammoths that compact the permafrost and prevent it from melting at higher temperatures than normally.
But there are also disadvantages to de-extinction. The revived species can have negative consequences for the ecosystem. It could be or become an invasive species putting in danger other species. It can make prey species extinguish if there are too many predators compared to before or create a competition for food and get one species extinct. There are hundreds of ways to harm the environment due to revived species. Another negative option that could happen would be that the revived species died due to its habitat having changed so much because of humans. Or humans itself could start poaching them to get a resource like elephants and ivory and end by extinguish them. It is also very expensive and can divert money to this cause instead to the conservation of actual species.
Leaving pros and cons a side, there are many candidates to be de-extinguished, such as the Wooly Mammoth, the Pyrenean ibex, the aurochs, quagga, passenger pigeon and the Thylacine.

No author (January 28, 2023). De-extinction. Retrieved from: https://en.wikipedia.org/wiki/De-extinction

The main idea of this article is how to prevent de extinction, one of their ideas is to put sperm of an animal on eggs of another animal. 

- What is de-extinction
- Tools of species resurrection
- Cloning for de-extinction
- Ethical considerations

I believe that de-extinction is very powerful because it helps you to have any species you want for any time you want. However it can be very risky to have de-extinction because something may go wrong and that "animal" maybe be a very dangerous animal. 

In this article they talk about de-extinction and do a short introduction of de-extinction. There are many candidates for de-extinctions but we still don't know which they are going to do first. German zoologists Lutz and Heinz Heck crossbred different types of cattle in an attempt to back breed for an animal that resembled the aurochs, an extinct species of European wild ox ancestral to modern cattle.

Dialogue:
I think that de-extinction should be carefully planned, if we decide to do it. We should avoid unplanned experiments, we must be very careful about consequences and conditions of the new species. At most, I imagine it as a very limited experiment, to understand and test technology, but not a tool that is widely used. In general terms, I prefer to care about what we have now and avoid playing God. The past shows us that, whenever man interfered with nature, results were awful. We can see it almost everyday, when we see non-native species of plants and animals that have invaded foreign areas, damaging local species and fostering devastation among native ones.

Summary:
De-extinction is about bringing an extinct species back to life. Methods for de-extinction can be divided into three large groups:
     -Back-breeding: which means recreating a primitive species by selecting/reproducing animals that look like the primitive to get something close to the old ones. But, in fact, there is little or no knowledge about what you are going to obtain and, definitely, you cannot get the real animal (neither regarding physical constitution nor behaviour).
      -Cloning (like Dolly the sheep): you take adn from one species and introduce it into an egg of another animal and then introduce this into a third animal, to obtain a clone. 
       -Synthesis: it is about making up a desired adn sequence as if it were a recipy. You get adn from the extinct species and compare it with the adn of a living one, to detect differences. Once differences are isolated, you can inject the new sequence (containing ith the differences) into the germinal line (eggs and spermatozoon) of the living species and cross- breed animals with the alteredsequences, to obtain something similar to the extinct one.
But the case is: what are we going to do with these species we will bring back? Are we aware of the consequences that this might bring? Are we prepared to offer them the right habitat to live? We need to consider that, once the old species disappeared, another species might have taken its place. So, when we return the extinct animal to its habitat, what will happen with the species that are currently living there? How will this affect them? Will there be enough space for the new species without threatening existent ones?

De-extinction should be limited in its scope, limited in its ambition and limited also regarding the species we bring back. Bringing back creatures from the past should help us to value and take care about what we have now, not to lose it. 

American Museum of Natural History. (2014). The Science Behind De-extinction. Retrieved from:  https://www.youtube.com/watch?v=Pkc_WodJxsk

There is no main idea because it explains to you everything about de-extinction. For example it talks about other reasons why de-extinction happens, how many species per year are being driven to extinction, how many native species of most land hanitats have fallen, how many vertebrate species have been driven to extinction and many more. 

- What is de-extinction
- Other force at play
- How many species per year are being driven to extinction
- Native species of most land hanitats have fallen 20%
- 680 vertebrate species have been driven to extinction since the 16th century

I believe that de-extinction is a very important problem after seeing all this graphics and data you also without knowing what de-extinction is that de-extinction is a serious problem we are facing right now. 

In this article we can see so many data that it even begin to look dangerous. It explains many things, for example what is de-extinction, how many species per year are being driven to extinction, how many native species of most land hanitats have fallen and much more. It gives you a defenition of  extinction, "Extinction, as it pertains to biology, is defined as “the dying out or extermination of a species.” This can be caused by a number of factors such as natural disasters, planetary shifts, movements of the sun and stars, human causation or evolution itself". We need to understand what probems we are facing now with de-extinction and how we can solve them.

Dialogue:
I believe it is totally unethical to experiment with animals like scientists are doing to de-extinct species. As it says in the article, many animals used for pregnancies or for genetic engineering suffer and die, and are treated just as tools. And also the embryos die due to failure in vital organs. And apart from the animal well-being, the ecosystem well-being is also in danger. But, it could have some good benefits by introducing the right animals in the right place.

Summary:
De-extinction is more or less targeting a species that is extinct, and bringing it back to life. It is also known as resurrection biology. First presented in 2013 as a serious scientific experiment. The first major project of an organization named Revive & Restore was to resurrect the passenger pigeon. 
Back in Nazi Germany, two brothers called Heinz and Lutz Heck, wanted to bring back ancient animals seen as "purity". They used back-breeding (similar to selective breeding) to bring back the aurochs and the tarpans and accomplished to make the Heck horse and the Heck cattle, similar to the species mentioned before. 
Another possibility to De-extinct is cloning, that can't bring back a dinosaur but it can an animal from which we have preserved DNA. For example passenger pigeons. The process to accomplish this is to use an egg with nucleus removed and "fertilized" with the DNA extracted from the extinct species. Then put that egg inside a surrogate and a baby from the extinct species should be born. But it has many problems apart from being really hard to reconstruct the genomes from the extinct species, sometimes even impossible, clones are normally born with serious health problems. The third possibility is genetic engineering. A company named Colossal had a 15 million dollars funding to bring back to life the woolly mammoth. They say that now, with new technology, they can actually do it. And this is thanks to genetic  engineering, which is using a gene editing tool named CRIPSR and going into certain genes and modify them to get the traits needed to look similar to the extinct species. 
Most of these experiments force animals to be inserted a "fertilized" egg. But should we really use them as surrogates? It is quite unethical to do so. Take for example an elephant. Elephants are very intelligent, and subduing them to be pregnant, have babies and watch them die once and once again is extremely cruel. And also the baby would suffer a lot, being full of health problems and having such a horrible short life. 

Kelley, Debra. (February 7, 2022). DE-EXTINCTION: WHAT IS IT, HOW MIGHT IT WORK, AND WHAT'S THE PROBLEM? Retrieved from: https://www.grunge.com/758859/de-extinction-what-is-it-how-might-it-work-and-whats-the-problem/

The main idea of this article is how to prevent de extinction, one of their ideas is to put sperm of an animal on eggs of another animal. 

- A Harvard University team was on the verge of resurrecting the wooly mammoth
- Concept of de-extinction
- How much it would cost to sustain a population of de-extincted animals
- The team considered two different scenarios

To sustain a population of de-extincted animals you would much money. It allows scientists to extrapolate the cost of preserving resurrected animals that are similar to living analogs. The cost of caring for a population of resurrected mammoths.  However instead of focusing the money on de-extinction, we would see a much bigger increase in biodiversity—roughly two to eight times more species saved.

In this article they talk about how much it would cost to sustain a world with all the extinded animals. The Harvard team considered 2 different scenarios. One where the government assumes responsibility, the result of this scenario would be an overall loss of biodiversity and about two species would go extinct for every one that could be revived. While in the second scenario private companies sponsor the project and the result whould be that we could see a small increase in biodiversity, especially for animals for which the necessary conservation tools and techniques are already being used to conserve existing endangered species.

Arguments/facts: 

          - Back-breeding
          - Cloning 
          - Genome Editing and Synthetic Genomics

Dialogue: In my opinion, if we know what de-extinction, how does it help de-extinction. We would have a lot done. We would have motivation to continue doing even if we failed. Due to the benefits it will bring us. Like we could find a plant that takes away more CO2 so all the contamination we have could be eradicated in a simple way and fast. That's only one of many examples of how we could used it in our benefit. We have already achieve de-extinction of some plants. So it's not something we will do in the future it's happening NOW. Because we could creates them by: Back-breeding, Cloning and Genome Editing and Synthetic Genomics.

Summary: In this webpage, it talks about many things but the main ones are: What is de-extinction? How Does De-Extinction Help the Ecosystem? How Is De-Extinction Possible?. So what is de-extinction? De-extinction is the reverses plant and animal extinctions by creating new versions of previously lost species. Like Back-breeding, cloning, and genome editing are ways for de-extinction of some species. The goal is to re-establish dynamic processes that produce healthy ecosystems and restore biodiversity. Restoring ecosystem functions lost through extinction of animals and species. This idea is the catalyst for de-extinction projects, to de-extinction of species. De-extinction is possible because of bioengineering techniques that can change DNA in the way we want. We could four the DNA of dinosaurs in their bones.

No Author, (No Date) How De-Extinction Works: Methods, Examples and Step-by-Step Process retrieved from: https://colossal.com/how-de-extinction-works/

Dialogue:
Now a days, they are looking ways to, return some plants they got de-extincted due to the meteorite. If we pressurect some plants, we could improve in medice due to we would have more resources. So we could cure more disease. An other thing they mentioned is how Jurassic World used DNA from dinosaurs so even now, they are looking for plants these doesn't meant, farther on they are going to used wit animals, so it eve doe they are no original there DNA is exactly the same so, animals could not get extinct, and the extinct animals would be resurrected. Moreover I don't like resurrecting animals because we are playing to be got deciding which animals lives and whites die, and these could get in our heats and would be a very scary weapon to use between nation because they could use all type of animals to attack between each other and the desire of having these would eradicate our society as we now it now. But for example in plants is different because you could used for better ways, I'm not saying it's not dangerous because it is but, we could rescue many lives.

Summary:
Talks about how we could de-extinct plants, and these would helps us. And even suggest we could try it with animals us Jurassic Parc, have done in they movies with dinosaurs, but they would try with another type of animals. They have a lot of facts like "palms in the eastern Mediterranean started to show increasing levels of genes from another species". They are giving an idea of how these could improve our lives.

Maisoon Mubarak & Rachel Harrison (May 5, 2021) How Scientists Are “Resurrecting” Extinct Plants to Study Their Evolution retrieved from: https://www.nyu.edu/about/news-publications/news/2021/may/resurrecting-extinct-plants.html

Dialogue:
In my opinion if we achieve all these things we need to ask many questions, like: Is it reasonable? Do we really need it? How is it going to change the environment?. These are only some of the main questions, but I could ask a lot more. We really need to reflection about these things, because once you have started, maybe you cannot go back and change it. We may be creating a lot of problems. THINK BEFORE ACTING.

Summary:
We should talk about how we are improving technology and how we have done it in the past few years. It is scary how fast we are evolving. With the technology we have, we would be able to de-extinct plants. But even if we created them, it would be very difficult to return them to their habitats and only a minor percent of these plants could succeed. It also states to reflect regarding this question: are we doing this to  achieve our expectations? If so, we would put a lot of excuses during the way.

No Author, (2 June 2022) Frankenstein's work or everyday conservation? Examining plant de-extinction in practice retrieved from: https://www.sciencedirect.com/journal/journal-for-nature-conservation/special-issue/106WXV11ZX9

DIALOGUE: 
I think de-extinction generates excitement: man has always wanted to be like God. But, how will we control the introduction of de-extincted species and its consequences? Wouldn´t it be wiser to accept evolution and use money to  protect current endangered species instead of bringing dead ones back to life? 
I wonder if we, humans, should aspire to create life and interfere with nature. Or, if we should respect nature and not cross certain limits.

SUMMARY:
De-extinction means bringing extinct species back to life. The article explains the consequences that this practice might have. There are many possible threats regarding de- extinction: 1. we would be introducting an extinct animal to a habitat that has changed a lot compared to when it was alive. We, humans, have changed the world: forests have been de-forested and replaced by urban or industrial facilities, lots of species have disappeared, polluting emmisions have increased and changed... So, it is simply not true that we would take the revived animal to its original habitat.  2. We would not be able to control how the introduction of the revived species would affect existent species (it might invade and take over the territory... it might migrate and alter balance of different zones). 3. The risen species would not be exactly the same it used to be; it would be a new species with some gens from the extinct one, but not identical. And we cannot predict how this new species will behave or affect. 4. Which species should we bring back? Which not? Why?
The article states that it is very exciting for some scientists to bring species back, but it is a dangerous experiment. It also proposes to differ the de-extinction until we further investigate possible consequences and develop methods to control them.

llester. (February 19, 2016). De-Extinction, a risky ecological experiment. Retrieved from: https://www.esa.org/esablog/2016/02/19/de-extinction-a-risky-ecological-experiment/

Dialogue: In my opinion even if we achieve our goal we have to think if, it will benefit us because it could be very revolutionary but we have to think we need to have precaution. If not these could run out of our hands so, they would be many problems and discussions all over the world to have these type of technology. So we would need and organization that regulates the use of these tool so, humans could not abuse from it.