Question: Is there a way to modify genes, for example giving an animal super strength on purpose or making an animal really big?

Renata Medeiros answered on 24 Jun 2013:

Very good question! The answer is, yes! In fact, people have been doing that for centuries with animals such as cows, sheep, dogs and cats! Although only recently we can actually modify genes in a lab (genetic engineering), selective breeding does the same trick (just takes a bit longer). Selective breeding means to select the animals with the characteristics you want and keep breeding them with one another until the newborn animals carry the genes for those characteristics . This is how we ended up with breeds of dogs that are super strong and good for fighting (bulldogs or boxers), dogs good at guarding livestock (shepherd dogs), dogs good at racing or hunting (greyhounds or retrievers) or dogs that are just cute and small (chihuahuas or miniature poodles). All these types of dogs are very much “created” by humans by naturally playing with their genetics, even before DNA was discovered! People just realised it worked!
Genetic engineering has been used mainly in crops but also in some animals (one example is a modification in cows for them to produce milk that does not cause allergies to people that cannot drink normal milk). So, in theory, we could modify an animal into being super big or super strong but people will probably only do it if there is some use to it, as these things are usually very expensive. Some people are still very much against genetic engineering because it can touch sensitive issues such as food safety or animal rights. It will be interesting to see how this will develop in the future!