一些專家還說，大量留在人世的超級老年人還將扼殺新生代的成長，阻礙社會進步。「讓老一代人消失的進化過程是有其智慧的，」埃默裡大學(Emory University)倫理中心主任保羅·魯特·沃爾普(Paul Root Wolpe)在一次關於延長壽命的公開辯論中表示。「如果經歷一戰和二戰的一代人，或者是經歷內戰的一代人還活著，你真的認為這個國家會有民權嗎？會有同性婚姻嗎？」

長期以來，科學家、哲學家和作家一直擔心，過多的時間會耗盡所有有意義的體驗，最終導致憂鬱和倦怠達到使人衰弱的水平。也許，對多活幾年的渴望掩蓋了某種難以企及的東西的更深層渴求：不是簡單地追求更長的生命，而是追求長到讓一個人感覺完美和完整的生命。

Devoting resources to maintenance is advantageous only if an organism is likely to continue surviving and reproducing.

只有當生物體可能繼續生存和繁殖時，將資源用於維護才是有利的。

For many organisms, external threats are too great and numerous to endure for very long, so there is not much evolutionary pressure to preserve their bodies in old age, resulting in their deterioration.

對很多生物來說，外來威脅太大、數量太多，無法長期忍受，因此在老年時沒有太大的進化壓力來保存它們的身體，從而導致它們的退化。

In a study published in Nature in December 2020, David Sinclair, a director of the Paul F. Glenn Center for the Biology of Aging Research at Harvard Medical School, along with colleagues, partly restored vision in middle-aged and ailing mice by reprogramming their gene expression.

The researchers injected the mice’s eyes with a benign virus carrying genes that revert mature cells to a more supple, stem-cell-like state, which allowed their neurons to regenerate — an ability that mammals usually lose after infancy.

“Aging is far more reversible than we thought,” Sinclair told me. “Cells can clean themselves up, they can get rid of old proteins, they can rejuvenate, if you turn on the youthful genes through this reset process.”

在2020年12月發表於《自然》的一項研究中，哈佛醫學院(Harvard Medical School)保羅·F·格倫衰老生物學研究中心(Paul F. Glenn Center for the Biology of Aging Research)主任戴維·辛克萊爾(David Sinclair)與其同事通過重新編寫基因表達，部分恢復了中年和患病鼠的視力。研究者為老鼠眼睛注射了一種良性病毒，這種病毒攜帶的基因可以將成熟細胞恢復到更柔軟的幹細胞樣狀態，從而使它們的神經元能夠再生——哺乳動物通常在嬰兒期後就失去了這種能力。「衰老的可逆遠超我們想像，」辛克萊爾告訴我。「只要你通過這個重置過程打開年輕的基因，細胞就可以自我清理，可以清除陳舊蛋白質，可以恢復活力。」

David A. Sinclair - Wikipedia

Imagine, some say, how wise our future elders could be. Imagine what the world’s most brilliant minds could accomplish with all that time.

有人說，想像一下我們未來的長輩會多有智慧。想像一下世界上最聰明的人能用這些壽命成就什麼。