A magazine I was browsing through today had an article in it written by a scientist. The scientist was talking about mice, and made a brief reference saying something like “although there are some scientists who claim to have ‘cloned’ these little guys, no method exists yet to truly ‘clone’ an animal.”
What is the writer referring to here? What does he mean that scientists can’t yet “truly” clone an animal?
(This a modern magazine, by the way. Not one from the late 1980s or anything).
It would help us answer your question if we knew at least the name of the magazine, and the name of the scientist, to give us a context, ya know? If it was the Reader’s Digest, that’s one thing; if it was the National Geographic or Smithsonian, that’s another.
Without the original text to read it is difficult to say what he was talking about.
That said given that we have cloned the sheep Dolly and a few other animals since I’m not sure what he’s thinking. Perhaps he means growing an animal in a test tube (so to speak). Dolly was implanted as an egg in another sheep who gave birth to her. There has been talk of cloning a Mammoth but given that there are no other Mammoth’s around to carry the fetus this is problematical. They have suggested using an elephant but no one is certain if that would work.
As for cloning dinosaurs and the like we may have to wait awhile if such a thing is ever possible.
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I’m not totally sure what magazine it was. I was in a doctors surgery and it was one of the many magazines piled up on the nearby coffee table. It was in the same genre as “Readers Digest” and those sorts of magazines, as in, a magazine full of lots of different stories and articles on many different topics.
I could go down there tomorrow and kind of walk in, have a quick peek, and walk out again, but god knows what the receptionist would be think I was doing.
I haven’t seen the article the OP refers to, but I’ll make a guess here and say that the scientist was defining cloning strictly as the duplication of an organism from a somatic (body) cell alone - that is, you should be able to take a skin cell, liver cell, blood cell, etc. and generate a clone directly from that. In contrast, the cloning efforts I have read about to date involve the extra step of placing the DNA of the animal to be cloned within a germ cell (egg) that has had its own nucleus removed. In the case of female clones, you could use the animal’s own germ cells to make the clone, but you’d need a female of the same species to donate an egg cell for any male animals you’d want to clone.
There has been talk of trying to clone now-extinct animals, but the process faces a lot of problems. First and foremost, DNA decays rapidly after the death of an animal unless extraordinary preservation of the organic material has occurred. The stuffed bodies of certain animals hunted into extinction, like the quagga, were examined in hopes of recovering some useful genetic material, but the passage of a few decades and the embalming fluids have taken their toll. Mammoths are still regarded as candidates for “resurrection” because we can find their frozen remains… but just a few hours of thawing here and there over the millenia would probably be enough to cause significant damage to their DNA. (Elephants would be the logical surrogates for this effort, as the closest living relative large enough to gestate a mammoth.)
It’s unlikely we’ll ever be able to really clone dinosaurs, for reasons that IIRC were described in “Jurassic Park” the book (but glossed over in the movie). Even if some fragments of dino DNA are preserved in bloodsucking insects encased in amber, the fragments do not an entire genome make, so we’d be missing in significant amounts of genetic information. In the story, those gaps are filled by frog DNA, with unexpected results (some dinos switched sex and bred, an amphibian trait - remember?). Assuming we reach the point of being able to stitch together dino DNA in that fashion, we’d have a genetic chimera, and not a true replica of the original animal.