The Doomsday Clock and the Challenges of Repopulating Earth after

The Doomsday Clock serves as a symbolic representation of humanity's proximity to self-destruction. It is not meant to be an accurate countdown but rather a metaphor for the general dangers we face at any given time. The clock was initially set in 1947, shortly after World War II, when the world was in a precarious state due to atomic bombings and escalating nuclear tensions.

Over the years, the time on the clock has been adjusted 24 times to reflect the changing existential threats humanity has encountered. Currently, the clock is set at 100 seconds to midnight, the closest we have ever been to our own annihilation. This proximity is attributed to ongoing nuclear threats, the rapid progression of climate change, and the emergence of cyber information warfare.

Considering the relevance of the Doomsday Clock, a question arises: If two people were the last survivors of a global catastrophe, could they repopulate the Earth? While the initial generation might not pose any problems in terms of reproduction, subsequent generations would face significant challenges due to the necessity of incestuous relationships.

Incest is universally taboo and deeply ingrained in human societies. It is not only morally repulsive but also biologically dangerous. Inbreeding increases the likelihood of inheriting harmful gene mutations, which can lead to severe inherited diseases. The human genome consists of thousands of genes, and mutations in some of these genes can result in debilitating conditions.

The consequences of inbreeding can be observed in real-world examples. The island of Pingelap in Micronesia experienced a loss of genetic variation after a typhoon left only 20 survivors. Today, one in ten people on the island suffers from complete achromatopsia, a rare color blindness condition. Similarly, the Habsburg dynasty, known for practicing strategic intermarriages, suffered from severe health issues, including the famous "Habsburg jaw."

Looking further back in history, Neanderthals, our closest relatives, are believed to have gone extinct partly due to inbreeding resulting from their small population size. Inbreeding reduces genetic diversity, making populations more vulnerable to diseases and other threats.

Considering the implications of inbreeding and the potential for catastrophic events, such as asteroid strikes or nuclear wars, it becomes crucial to explore the possibilities of colonizing other planets. Currently, no habitable planets exist nearby, and Mars would require extensive terraforming efforts. The closest star to us, Proxima Centauri, is 4.2 light-years away, posing significant challenges for interstellar travel.

To ensure the survival of our species, scientists are exploring the minimum viable population necessary to maintain genetic diversity on long space journeys and eventually repopulate another planet. According to astrophysicist Frederick Marin, a minimum of 98 individuals would be required for a 6,000-year journey to Proxima Centauri on a space ark.

Although this question may seem hypothetical, understanding the implications of inbreeding and the challenges of interstellar colonization is vital for the long-term survival of humanity. By expanding our knowledge and technological capabilities, we can increase our chances of overcoming potential catastrophes and securing a future beyond Earth.

In conclusion, the Doomsday Clock serves as a powerful metaphor for humanity's proximity to self-destruction, highlighting the existential threats we face at any given time. The current setting of the clock at 100 seconds to midnight underscores the urgency of the challenges we confront, including nuclear threats, climate change, and cyber information warfare.

Considering the scenario of global catastrophe and the last survivors attempting to repopulate the Earth, the taboo and biological dangers of incest become evident. Inbreeding increases the risk of harmful gene mutations and inherited diseases, as observed in real-world examples like Pingelap Island and the Habsburg dynasty. The loss of genetic diversity due to inbreeding can make populations more susceptible to diseases and other threats, as seen in the case of Neanderthals.

Ultimately, through continuous scientific advancement and exploration, we can strive to secure the future of humanity beyond the boundaries of our home planet.