Thursday, January 21, 2010

Artificial Selection



Artificial selection is a scientific term used to describe the breeding of plants and animals for desirable traits and not necessarily those that would allow the offspring to better survive in the wild. It is also known as selective breeding, artificial selection, and unnatural selection. The process can be considered the exact opposite of natural selection.

How is it done?

Artificial selection is relatively easy to accomplish. A specific plant or animal is chosen because it has a specific heritable genetic trait that the breeder desires. The plant or animal is then bred with another of its kind with a similar trait, resulting in offspring with a higher potential to display the specific trait. This cycle can be repeated with the offspring until the specific trait is achieved at the desired level.






Examples of artificial selection:

There are dogs, plants, cows, crops, cats and many other selections of living things around the world. There are over 150 different dog breeds, from tiny chihuahuas to giant Great Danes, but they are the same species and all are descendants of wolves. if a breeder wanted a dog with a curly coat, he or she would allow curly-coated dogs to breed and not allow them to breed with straight-coated dogs. Over the years, the plants with desirable characteristics are grown by man and their numbers increase. Meanwhile, plants without these characteristics are less likely to survive as they are not provided with the fertilizers and pesticides by man. Eventually, the species of the plant will evolute. Cows are artificially selected to make them stronger, grow faster, reproduce healthy and strong cattle and to produce more milk. These super cows grow stronger muscles and live longer than usual cows.


Good or Bad?

Inbred offspring are one of the potential dangers of too much artificial selection. Some traits are so rare that they can only exist in one or two family lines. If the trait is recessive, two members of the same line (relatives) may have to be bred together in order for the trait to be visible. In animals, this can result in genetic defects and other serious problems.

The results of artificial selection are easy to see. The domestication cycle of dogs (canines) being bred by their owners in order to emphasize less aggressive traits has gone on for thousands of years, and has resulted in hundreds of different breeds that look almost nothing like their grey wolf ancestors. Dairy cattle are bred in hopes of producing more milk, but some lines now suffer from increased infections and fertility problems. Persian cats that are bred for extremely flat faces often develop respiratory problems and may have trouble eating. All of the listed traits that are bred for do not help the animals survive in the wild, but do make them more desirable to their owners.

In my opinion this has gone way out of line. breeding animals and plants? who's next, us?!



Should we artificially select plants or animals?

Studies have shown that artificial selection has a lot of potential applications in the field of medicine and which remains a pursuit of the future. It shows that artificial selection can even be put into humans. For example, stem cell research. The ethical questions that have begun to be asked in the setting of stem cell research has remained a hot topic in recent years. But it seems impossible that research will ever be legal. Stem cells are able to become any cells of the body and are a perfect match to each person. Artificial selection lets researchers to select the best stem cells from their Petri Dish. So, once these stem cells are allowed to distinguish into organs, the best organs can be selected so the recipient receives the best possible benefit.

Drug production can also assist from artificial selection. Some of our medications are made by genetically modified bacteria. Selection technology can allow laboratories to breed viruses that are able to make the mixtures at the fastest rate, improving the efficiency of medicine production.

In my opinion, i strongly disagree with selective breeding. I think it's wrong to choose how someone or thing should appear in public. Yet again there's always advantages and disadvantages in this subject. Disadvantages would be for show animals such wild kitten eatingas some dogs, it is practised quite strictly by breeders aiming at a certain look which is set down as the breed "standard". Many Dalmation puppies are euthanased because they do not exhibit the breed standards for example, so there are serious moral questions to it too.Too much close interbreeding to obtain certain cosmetic traits can also result in the amplifying of inherent illnesses; like the bulldogs mentioned above, or German shephered dogs with hip problems and so on. In fact, these issues are rapidly worsening in recent years with dogs in particular. The advantages would be that it can produce fitter, stronger animals or animals of a higher yield of milk, meat or eggs for example. Can produce animals better suited to survive in poor climates or marginal conditions, thus preserving human food supplies and saving life, and can ensure the eradication of hereditary sickness in some blood lines.

Seals, sharks, polar bears, and sea otters are just few of the animals that are examples of species being endangered. This all happens because of us humans. For example, we take tigers, lions, foxes to make fur out of them for us to be able to dress warmly and show off. This should not be happening. It is cruelty to skin animals and to use them. Another example would be shark fins. We use them for our own luxury. But if you could take all these animals and selectively breed them, why wouldn't you? They would no longer be at risk and we would feel proud of saving them.

In conclusion, I think, yet again, that we are to blame for everything but at the same time this could be used in a good way. For animals, it could be used in a way that could bring us good. What if we were to engineer chickens into making more eggs? That would be a useful thing for everyone because they are a source of high protein. With humans though, why put chemicals and different hormones in a child that is not even born yet? Why make them suffer just because the parents wanted that child to have green eyes, or blonde hair? In the end, there are both positive and negative sides to artificial selection. Maybe we could get plants to grow twice as fast so that we can have more photosynthesis which could give us more energy to wake up in the morning and go to school.

sources:

http://en.wikipedia.org/wiki/Artificial_selection

http://animals.howstuffworks.com/pets/dog2.htm

http://www.windows2universe.org/cool_stuff/tour_evolution_7.html




Wednesday, January 13, 2010

Designed to Live for the Sake of Someone Else's Life?


What is a designer baby? A baby whose genetic makeup has been artificially selected by genetic engineering combined with in vitro fertilisation to ensure the presence or absence of particular genes or characteristics. reproductive techniques involve using in vitro fertilisation to fertilise eggs with sperm in test-tubes outside the mother's body in a laboratory.


Are things getting out of hand with our research into genetic processes?

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Why is it done? First, it all depends on the mother and the father. Maybe they both have a recessive gene for cancer, and they do not want their child to get that chance. Sometimes it is done to genetically modify your child. People want to decide on the gender of their child, or their looks. Sometimes it is done just for another child.

Example, My Sister's Keeper. In this movie, a girl named Kate Fitzgerald, is diagnosed with acute promyelocytic leukemia, which is a type of cancer that affects the blood and bone marrow. The parents of Kate then decided to conceive Anna through in-vitro fertilisation to be a donor for Kate and maybe someone who could save her life and make her cancer-free. The parents though, in my opinion, use Anna. They make her donate blood for Kate from the age of three and use her as a donor for other bodily substances as Kate goes through remission and relapse.This is another reason for designer babies. I disagree with this on all points. It is against nature to use a child's body without their agreement from such a young age. They are being put through a lot of pain and too much suffering. Either way, in the end, Kate dies. What if Anna would've given her a kidney and her body would have refused it? What would the point have been to put Anna through pain all along? Kate's cancer would relapse and the story would start from the beginning all over again. The movie was sad, but at the same time I learned something new that shows me what this world and science are capable of. A quote that really inspired me was said by Anna at the beginning of the movie:

"On the other hand, I was born for a very specific purpose. I was born because a scientist managed to hook up my mother’s eggs and my father’s spern to create a specific combination of precious genetic material. I, the great disbeliever, decided to ask my parents the truth, and I got more than I bargained for. They sat me down and told me all the usual stuff, of course, but they also explained that they chose little embryonic me, specifically because I could save my sister, Kate. “We loved you even more,” my mother made sure to say, “because we knew what exactly we were getting.” It made me wonder though, what would have happened of Kate had been healthy. Chances are I’d still be floating up in Heaven or wherever, waiting to be attached to a body to spend some time on earth. Certainly I would not have been part of this family."



But how are these designer babies really created? It is all done through vitro-fertilisation or as scientists refer to it, VF. An embryo is fertilised in a test tube with other embryos that are as well candidates for being implanted in the mother's womb. The parents then decide which one would be best, and thus implant it. If the child is not the way it should be, it is thrown out. And that right there could have been a life. But it is killed against its will. Why would we waste a precious life just to get something more perfect? God gave us life as a gift, not something we throw out or genetically engineer.


Preimplantation Genetic Diagnosis- PGD basically means embryo screening and its main advantage is that it is used to avoid passing on the genetic disorders that parents might pass on to their kids. How is it done? A group of embryos are taken away from the mother and grown to the eight-cell stage which is the stage soon after conception, where the fertilized egg has begun to divide. At the moment that these cells have reached the wanted stage, one or two cells are taken and checked to be free from the genetic variations that are associated with the disease before being introduced into the womb. That is how it is made sure that the child will be disorder free.

Ethical Problems- So, is this idea brilliant? Is it a good thing that we are artificially selecting our child's genetic makeup? Do we all agree on ensuring on the presence or absence of some particular genes? I completely disagree against this. For me, it is a terrible idea just to make out future look better and for science to go even further. Why chance a life? Why not leave it the way it is? Life's a gift to be pleased about and to give thanks to. We are all created in a particular way to be different from the other. Would we want the world to be identical? Blonde hair and blue eyes? That seems awfully dull.Scientist on the other hand, believe that this is something that is going to change our look on children. Also this experiment costs something over 18,000 just for an embryo to be screened for a desired sex (boy or girl) and the prices would just go up if we want to change other traits. Other ethical problems include custody battles over fertilized embryos that were frozen but never put to use.

Questions about what to do with embryos left over a successful pregnancy, and the increased health risks posed by multiple births. Yet, no one is suggesting that this be stopped. The ethical issues raised by techniques beginning from the genetics labs are likely to be even more complex. What if parents can use preimplantation genetic diagnosis to avoid having kids with attention-deficit disorder, or those destined to be short or dullwitted or predisposed to homosexuality? Will they feel pressure from friends and relations to do so? And will kids who are allowed to be born with these characteristics be made to feel even more like second-class citizens than they do now?

Conclusion-There are many questions left that are not yet answered. In my opinion, we should stop, or we should argue on this case. It's sad to see such a thing being created. Our world just wants to turn us into robots. In science, something new is created every day. Some creations are good, some are not. The good I see in this? The reduction of diseases or PGD. If mother and father have had a family member diagnosed with cancer or if they have cancer, why not want to reduce that chance for your child? It's something that you carry on your shoulders knowing that your child might get sick at a young age. It's something not all of us want to happen. What if your grandmother had Alzheimer's? Would you want your child to grow up and slowly start forgetting things? No, we do not want those genes to be carried on through our blood, passed on to generations. If this is the only way we can get rid of that, then yes, maybe I'd take the chance, but then after all, things do happen for a reason.


Sources-