{"id":189,"date":"2021-11-02T05:00:25","date_gmt":"2021-11-02T04:00:25","guid":{"rendered":"https:\/\/www.sciencefocus.com\/?p=104097"},"modified":"2021-11-02T05:31:11","modified_gmt":"2021-11-02T04:31:11","slug":"doctor-who-could-regeneration-really-be-possible","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/rss_feed\/doctor-who-could-regeneration-really-be-possible\/","title":{"rendered":"Doctor Who: Could regeneration really be possible?"},"content":{"rendered":"

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By Stephen Kelly\n \t\t<\/p>

Published: Tuesday, 02 November 2021 at 12:00 am<\/p>

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One of the main reasons why Doctor Who<\/em> \u2013 both the show and the character \u2013 has survived so long is the concept of regeneration. Every time the Doctor dies, the character is renewed \u2013 their cells rewritten, their wounds repaired, their severed limbs regrown. It\u2019s a process that Jodie Whittaker\u2019s 13th Doctor will be undergoing soon, with her final series on air on BBC One since 31 October.<\/p>\n

The idea of a regeneration so extreme that it can transform one person into another is, of course, a bit fanciful. But the basic tenets of regeneration (extending life, regrowing body parts) is science fact in the animal kingdom \u2013 and one day, it might be for us too.<\/p>\n

\u201cI\u2019m old enough to say, \u2018never say never,\u2019\u201d says Alejandro S\u00e1nchez Alvarado<\/a>, a molecular biologist at the Stowers Institute for Medical Research in Kansas. Alvarado studies the regenerative abilities of planarian flatworms. Remember that episode of Doctor Who<\/em> where a new David Tennant grows out of the 10th Doctor\u2019s severed hand? Well, flatworms do that for fun. \u201cThey can be sliced and diced in every imaginable way,\u201d says Alvarado, \u201cand each piece will regenerate a complete animal.\u201d<\/p>\n

There are other examples too. Deer can regrow their antlers exactly as they looked before. The spiny mouse can have its skin torn off by a bird and grow it back. Salamanders and newts can repair limbs and organs. Snails can lose an eye nearly as complex as a human\u2019s and regenerate a new one. Some species of Hemichordate, a group of marine invertebrates, can spring a new head after decapitation.<\/p>\n

These animals share some factors. They tend not to scar over when injured, meaning the wound epidermis can remain in contact with the underlying tissue. They tend to have an abundance of stem cells and\/or cells that display some degree of plasticity. But what leads to certain animals developing those attributes? How do they use them to regenerate? And why can certain animals regenerate limbs and humans can\u2019t? \u201cThose are the kinds of questions that we\u2019re struggling with,\u201d says Alvarado.<\/p>\n

Humans do have some regenerative abilities. The liver can repair itself. Our blood system is constantly regenerating. And there are cases of people regrowing the tops of severed fingertips (if the wound is left open). \u201cYou have to lose your digit without losing the base of your fingernail,\u201d says Alvarado. \u201cThe base has stem cells that can get activated to produce not just the nail but also connective and bone tissue.\u201d<\/p>\n

\""Illustration\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
\u00a9 Kyle Smart<\/span><\/figcaption><\/div>\n

Such regenerative quirks suggest that humans once had the ability to regenerate, but it\u2019s now dormant. \u201cThe question is,\u201d asks Alvarado, \u201cif we had it, why did we lose it?\u201d Theories range from regeneration being incompatible with intelligence to it being an evolutionary trade-off to suppress our rates of cancer. But Alvarado is optimistic it can be reactivated. Imagine, for example, being able to regrow a foot after it\u2019s been amputated. Or repair a heart damaged by cardiac arrest.<\/p>\n

\u201cThe fact that our molecular toolkit is almost indistinguishable to other vertebrates that can regenerate means it should be possible to engineer a means to introduce the ability of certain tissues to restore themselves. That, I think, is perfectly feasible! We\u2019ll probably see that in the next 30 to 40 years.\u201d More than enough time to also build a phone box that travels through time.<\/p>\n

Verdict: <\/strong>We can\u2019t do it now, but medical science might just allow us to regenerate in the near future.<\/p>\n