Notes

TIM: Weird.




TIM: Dear Tim and Moby, What can you tell me about cloning? From, Frieda.


TIM: Funny you should ask. Clones are organisms, or parts of organisms, that share the same exact genetic information. Believe it or not, people have been creating them for thousands of years. Ancient farmers cloned crops by cutting off a piece of a plant and replanting it somewhere else.




TIM: That technique is called, er, cutting. And in the early 1900s, scientists started experimenting with splitting animal embryos in the lab, to create twins. This can also happen naturally, before birth—the result it identical twins with DNA from both parents. Creating a cloned animal from a single adult parent is more difficult.




MOBY: Beep?


TIM: In 1996, scientists used a single adult sheep cells to produce a cloned sheep named Dolly.




TIM: Their process revolved around DNA, the molecule that carries genetic information. DNA was removed from one cell nucleus, copied, and injected into another. The technique used to create Dolly required the help of three different sheep: One provided the DNA, which was injected into the egg cell from the second one, and the third one carried the pregnancy.




TIM: But this isn't the only way to create clones. Scientists are always experimenting with new options, because clones could be really useful. The best livestock could be cloned on farms.




TIM: And we may soon be able to clone new organs and body parts for people with diseases and injuries.




TIM: One day, cloning could even bring extinct animals back to life using DNA in remnants of their fur or bones.




TIM: But as exciting as it is, there are still problems with cloning.


MOBY: Beep?


TIM: Well, for one thing, that sheep, Dolly? She aged early and died at a pretty young age. Though it's hard to say whether that was because of the cloning process. When scientists later used the same cells Dolly came from to make more clones, they turned out very healthy.




TIM: Identical DNA can pose other risks. Let's say a virus comes along that's deadly for some wheat plants. In a normal crop of wheat, that's no big deal. Some of the wheat will die, and some won't since their different DNA gives them different traits.




TIM: But if all the wheat in a crop has the same DNA—and therefore, the same traits—the farmer better hope that that clone is resistant to the virus. If not…




TIM: Finally, there are ethical questions about cloning. Is it right to clone animals when so many of them develop diseases and age rapidly? Is it ever right to clone human embryos? Well, philosophers and scientists and politicians are still debating these issues. Cloning is a pretty big power for humans to have, and it raises a lot of tough questions.


MOBY: Beep.




TIM: Hey, how'd you do that?