Secrets to Long Life Revealed by Examination of Extinct Tortoise Species’ DNA

Category: Science/Environment

Listening

Unlocking Word Meanings

Read the following words/expressions found in today’s article.

  1. longevity / lɑːnˈdʒev.ə.t̬I / (n) – the period or length of one’s life
    Example:

    The scientists are amazed by the animal’s longevity, which reached over 100 years.


  2. hold the key to (something) / hoʊld ðə kiː tə / (idiom) – to have the explanation for something
    Example:

    Many scientists believe that a healthy diet holds the key to a long life.


  3. rarity / ˈrer.ə.t̬I / (n) – something that is unusual
    Example:

    It is a rarity for humans to live past 100 years; most reach only 70 years old.


  4. susceptible / səˈsɛptəbəl / (adj) – easily harmed
    Example:

    Animals that have a weak immune system are susceptible to diseases.


  5. stave off / steɪv ɑːf / (phrasal) – to prevent or stop something from happening
    Example:

    The tortoises have developed a very strong immune system that can stave off diseases.


Article

Read the text below.

A team of researchers is studying the DNA of a Pinta Island tortoise [TAWR-tuh s] / ˈtoɚtəs / to determine the animal’s secrets to longevity.


The Pinta Island tortoise, called Lonesome George, died in 2012 at the age of 101. He was the last of his kind in the world because his species became extinct. Despite the extinction of his species, researchers from Yale University were able to collect samples of his DNA two years before he passed away in a conservation center in the Galápagos Islands.


Now, the researchers are using those DNA samples to determine what attributes help the species live for more than a century. The researchers think that those attributes might hold the key to discovering how humans can age in a healthier way.


While cancer is a disease that greatly harms humans, especially when they grow older, the researchers observed that it is a rarity among the Pinta Island tortoises. This phenomenon raised questions because larger species with long life expectancy like tortoises are more susceptible to developing cancer. To explain the phenomenon, the researchers compared Lonesome George’s DNA with that of other tortoises and animals.


Based on the researchers’ examination, Lonesome George’s DNA had produced and duplicated genes that can prevent the growth of cancerous tumors. The researchers also discovered genes that can stave off bacteria, viruses, and parasites.


Aside from finding the secrets to Lonesome George’s longevity, the researchers also want to study how tortoises developed gigantism, or the unusual largeness of the body. The team is also interested to learn how the species and other reptiles can regrow body parts and, hopefully, apply such knowledge in possible treatment of injuries in humans.


Viewpoint Discussion

Enjoy a discussion with your tutor.

Discussion A

• Why is it important to preserve the DNA of extinct species like the Pinta Island tortoise?

• If you were given the opportunity to study an animal’s unique quality (e.g. unusual size), what would it be? Discuss.


Discussion B

• Why do you think some species live longer than others?

• What do you think would happen if all animals could live for over 100 years?