I enjoy writing about artificial intelligence, but the real fun comes when I use it. Recently I had a long conversation with ChatGPT about the future of humanity. Specifically, how our species might evolve if we manage to terraform other planets in the solar system.

I wanted to explore the concept of speciation. I gave it the starting point — humans start to settle on or around other planets and moons over the next 100 years, within 500 we begin terraforming. Something happens after 1,000 years that leaves all the different clusters of humanity isolated from one another.

I then had the AI speculate on how humans might evolve over the next 10,000 and then 50,000 years until it reaches true speciation, including when/or if we reach the point where a Martian can’t survive on Earth.

Here’s how that fascinating conversation unfolded.

Inner System Planets

Homo-martianus (Mars)

Mars, the first planet humanity terraformed, presents unique challenges despite its proximity to Earth. Its lower gravity and colder climate would drive significant adaptations over millennia. Homo-martianus would likely develop taller, leaner bodies due to the reduced gravity, with elongated limbs and lighter bone structures. Their skin would darken or adapt to handle higher levels of UV radiation due to Mars’ thin atmosphere. Enhanced lung capacity and altered circulatory systems would optimise oxygen utilisation in the lower atmospheric pressure. While they might still be compatible with Earth in the early stages, prolonged isolation could lead to physiological changes making their return to Earth more challenging over time.

• Timeline of Adaptations:
  • 1,000 years: Minor changes in bone density and lung efficiency.
  • 10,000 years: Noticeable height increase, darker skin, and enhanced oxygen processing.
  • 50,000 years: True speciation, incompatible with Earth without technological support.

Homo-venusianus (Venus)

Terraforming Venus would require massive cooling efforts and atmospheric transformation, but if achieved, its Earth-like gravity and thick atmosphere would provide unique evolutionary pressures. The extreme heat and intense solar radiation would shape Homo-venusianus into a robust and heat-resistant species.

Humans on Venus might develop highly pigmented, radiation-resistant skin to protect against lingering UV rays. Their respiratory systems would adapt to handle higher atmospheric pressure, and their metabolism might evolve to cope with hotter conditions.

• Timeline of Adaptations:
  • 1,000 years: Early heat resistance and darker skin tones.
  • 10,000 years: Compact, efficient bodies adapted to high-pressure atmospheres.
  • 50,000 years: Fully adapted species with heat-tolerant physiology and thickened skin.
• Compatible with Earth: Yes, with difficulty. Their physiology might be too adapted for Venus’ extreme heat to handle Earth’s cooler climate.

Asteroids and Dwarf Planets

Homo-ceresian (Ceres, Dwarf Planet in the Asteroid Belt)

Ceres is known for its low gravity, briny subsurface water, and frequent water vapour emissions. Colonists would likely rely on these resources while contending with cosmic radiation. Homo-ceresian would develop elongated limbs and compact muscles for low-gravity movement. Their radiation-resistant, metallic-toned skin would protect them from cosmic rays, and they’d evolve efficient water retention systems for survival in a resource-scarce environment.

• Timeline of Adaptations:
  • 1,000 years: Minor adaptations for radiation resistance.
  • 10,000 years: Noticeable elongation of limbs and metabolic changes for water retention.
  • 50,000 years: Fully adapted species unable to survive Earth’s gravity.
• Compatible with Earth: No. Their elongated limbs and low-gravity adaptations would make movement on Earth incredibly difficult.

Homo-plutonius (Pluto, Dwarf Planet)

Pluto’s cryogenic temperatures and weak sunlight would push humans to the limits of survivability. Any colonisation would likely occur underground or near geothermal heat sources. Homo-plutonius would evolve stocky, insulated bodies with thick, frost-resistant skin. Their metabolism would slow, allowing them to enter semi-hibernation during resource shortages. Large, reflective eyes would adapt to detect heat signatures in the dark.

• Timeline of Adaptations:
  • 1,000 years: Early frost-resistant skin and metabolic efficiency.
  • 10,000 years: Noticeable changes in body insulation and semi-hibernation abilities.
  • 50,000 years: Fully adapted species unable to survive Earth’s climate.
• Compatible with Earth: No. Their bodies are too specialised for Pluto’s extreme cold to handle Earth’s climate or gravity.

Moons

Homo-titanus (Titan, Moon of Saturn)

Titan’s thick nitrogen atmosphere and frigid temperatures make it an intriguing candidate for human colonisation. Despite the cold, its lakes of liquid methane and ethane offer a wealth of resources. Over tens of thousands of years, humans on Titan would develop thick, insulating skin with subdermal fat layers to withstand the cold. Their large, dark eyes would adapt to low light, while their stocky, heat-conserving bodies would help maintain warmth. Broad nasal passages would warm and filter the dense, nitrogen-rich air.

• Timeline of Adaptations:
  • 1,000 years: Early changes in skin thickness and lung efficiency.
  • 10,000 years: Noticeable fat layers and low-light vision.
  • 50,000 years: Fully adapted species incompatible with Earth.
• Compatible with Earth: No. Their heat-adapted bodies and respiratory systems would struggle in Earth’s warmer temperatures and thinner atmosphere.

Homo-europaeus (Europa, Moon of Jupiter)

Europa is covered in a thick shell of ice with a subsurface ocean. High radiation from Jupiter’s magnetosphere makes its surface hostile, but humans might live near the oceans or beneath the ice. Aquatic adaptations would define Homo-europaeus. Webbed hands and feet, bioluminescent patches on the skin for communication, and translucent, radiation-resistant skin would all be common. Their eyes would be large and adapted for low light, and they might develop slim, streamlined bodies to swim through subsurface waters.

• Timeline of Adaptations:
  • 1,000 years: Early aquatic adaptations like webbed fingers.
  • 10,000 years: Noticeable bioluminescence and translucent skin.
  • 50,000 years: Fully aquatic species unable to survive on land.
• Compatible with Earth: No. Their aquatic and low-light adaptations would make survival on Earth’s surface difficult without technological support.

Homo-ganymedis (Ganymede, Moon of Jupiter)

Ganymede, the largest moon in the solar system, has a thin oxygen atmosphere and potential subsurface oceans. It also has its own magnetic field, which offers some protection from Jupiter’s radiation. Ganymede’s humans would have moderately tall, muscular builds to adapt to low gravity while maintaining radiation-resistant, metallic-hued skin. Their enhanced lung capacity would help them extract oxygen from the thin atmosphere, and their sensory systems might evolve to detect vibrations in the icy terrain.

• Timeline of Adaptations:
  • 1,000 years: Early adaptations in lung efficiency.
  • 10,000 years: Noticeable muscular changes and radiation resistance.
  • 50,000 years: Fully adapted species with limited compatibility with Earth.
• Compatible with Earth: Yes, with difficulty. Their physiology would work on Earth, but their bodies might struggle with Earth’s stronger gravity.

Beyond the solar system

Homo-proximus (Proxima-c, Orbiting Proxima Centauri)

Proxima-c, orbiting the red dwarf Proxima Centauri, presents a unique set of challenges for human settlers. Likely a super-Earth with higher gravity and frequent stellar radiation flares, the planet’s dim light and potential for a dense atmosphere offer distinct evolutionary pressures.

Humans on Proxima-c would evolve stocky, muscular builds to handle the higher gravity. Their skin would develop a dark, metallic sheen to resist radiation, while their large, reflective eyes would adapt to infrared light. Enhanced lungs and circulatory systems would ensure survival in a denser atmosphere. These adaptations would make them resilient and efficient on Proxima-c, but their physiology might struggle with Earth’s brighter light and oxygen levels.

• Timeline of Adaptations:
  • 1,000 years: Early muscle and circulatory system enhancements for high gravity.
  • 10,000 years: Noticeable changes in skin pigmentation and radiation resistance.
  • 50,000 years: Fully adapted species with limited compatibility with Earth.
• Compatible with Earth: Yes, with difficulty. Their stronger musculature could handle Earth’s gravity, but their eyes and metabolism might struggle with Earth’s environment.

Table of Future Human Species

Species Name	Planet/Moon	Special Traits	Compatible with Earth?
Homo-martianus	Mars	Tall, lean bodies, UV-resistant skin, enhanced lungs, light bone structure	Yes, with difficulty
Homo-venusianus	Venus	Compact bodies, heat resistance, thick skin, darker pigmentation	Yes, with difficulty
Homo-titanus	Titan (Moon of Saturn)	Thick skin, dark eyes, stocky bodies, broad nasal passages	No
Homo-europaeus	Europa (Moon of Jupiter)	Webbed limbs, bioluminescent patches, translucent skin, aquatic adaptations	No
Homo-ganymedis	Ganymede (Moon of Jupiter)	Metallic skin, enhanced lungs, compact musculature, vibration sensitivity	Yes, with difficulty
Homo-plutonius	Pluto (Dwarf Planet)	Frost-resistant skin, semi-hibernation metabolism, large reflective eyes	No
Homo-ceresian	Ceres (Asteroid Belt)	Elongated limbs, radiation resistance, water retention efficiency	No
Homo-proximus	Proxima-c (Exoplanet)	Stocky build, metallic skin, large infrared-adapted eyes, enhanced lungs	Yes, with difficulty

Homo-sapiens (Earth)

If humanity continues to evolve over the next 50,000 years under relatively stable ecological conditions on Earth, the changes would likely be more subtle and driven by cultural, technological, and environmental pressures rather than extreme natural selection. Here’s a speculative look at what humans might look like in such a scenario:

Physical Evolution

1. Height and Build:
   • Humans have been gradually growing taller over the past few centuries, partly due to improved nutrition. If this trend continues, average human height may increase slightly, though biological limits would prevent indefinite growth.
   • A more sedentary lifestyle due to technology could lead to leaner, less muscular builds unless counteracted by fitness culture or biotechnological enhancements.
2. Facial Features:
   • Larger eyes: Increased screen usage and reliance on artificial lighting might favour slightly larger eyes for better low-light vision.
   • Reduced jaw size: As diets become softer and less reliant on chewing (due to processed foods), jawlines may continue to shrink. Wisdom teeth could become increasingly rare as they lose functionality.
   • Smoothed facial features: Genetic mixing across populations may lead to more homogenised global features, with distinct regional traits becoming less pronounced.
3. Skin Colour:
   • Skin tone might become more uniform globally due to interbreeding across populations, potentially trending toward a medium-brown hue.
   • However, in regions where sunlight exposure remains strong, darker skin tones might remain prevalent. Alternatively, if humans live primarily indoors, lighter skin tones may dominate.
4. Dexterity:
   • Fingers and thumbs may become slightly more slender and agile due to increased use of technology and fine motor skills.

Technological Influence

1. Integration with Technology:
   • Humans might develop biological-technical hybrids, where implants and genetic modifications are common.
   • Neural implants could enhance memory, learning, or communication, effectively merging humans with artificial intelligence.
2. Reduced Physical Activity:
   • The reliance on automation and artificial intelligence could reduce the need for physical labour. Without counteractive measures, this might lead to weaker musculature and potentially a higher prevalence of obesity.
3. Sensory Adaptations:
   • Enhanced vision or hearing through genetic engineering might become widespread, creating “upgraded” humans capable of detecting a broader spectrum of light or sound.

Cognitive and Behavioural Evolution

1. Intelligence:
   • Average intelligence might increase due to cultural selection for educational attainment and the integration of AI augmentation. However, this assumes equal access to technological enhancements and education globally.
   • Alternatively, reliance on technology for memory and problem-solving could reduce the need for certain types of natural intelligence, creating a more specialised but less broadly capable brain.
2. Social Structures:
   • With advanced communication tools, humans may become less individualistic and more interconnected, fostering global collaboration. However, this could also lead to reduced privacy and individuality.
3. Mental Health:
   • Increased use of technology and urbanisation may exacerbate mental health challenges, but advancements in neuroscience and psychology might mitigate these effects.

Health and Longevity

1. Disease Resistance:
   • Advances in medical technology and genetic engineering could significantly reduce the prevalence of genetic disorders and increase resistance to diseases.
   • Antibiotic resistance or new pathogens might still pose threats unless addressed by global healthcare innovations.
2. Lifespan:
   • Humans might live well beyond 100 years, with 120–150 years being a realistic average due to advancements in anti-aging therapies and organ regeneration.

Speculative Features of Future Humans

Feature	Description
Height	Taller average height, possibly 6’2″–6’6″ for men, 5’10″–6’2″ for women.
Skin Tone	More homogenised global skin tone, trending towards medium-brown hues.
Eyes	Slightly larger, adapted for low-light conditions and extensive screen use.
Jawlines	Smaller jaws and fewer wisdom teeth due to softer diets.
Dexterity	Slender, highly agile fingers adapted for fine motor tasks.
Brain-Technology Link	Neural implants for memory enhancement and direct communication.
Lifespan	Average lifespan of 120–150 years with advanced healthcare.

In 50,000 years, assuming no drastic ecological changes, humanity’s evolution would likely be subtle, driven more by cultural and technological shifts than by natural selection. While physical changes such as height, skin tone, and sensory adaptations might occur, the most profound transformations would likely involve our integration with technology and extended lifespans. The humans of 50,000 years in the future might look similar to us outwardly but could functionally and cognitively be almost unrecognisable.

Conclusion

Speculating about humanity’s future in space is an exercise in imagination and science. Our ability to adapt—or evolve—to new worlds will determine whether we thrive or fade away. Each of these speculative species reflects the incredible versatility of life and the profound influence of environment on evolution. While some may thrive in their alien worlds, their connection to Earth would weaken over millennia, creating beings as alien to us as we are to our distant ancestors.

One thing is certain: as we step beyond Earth, the diversity of humanity will expand in ways we can only imagine, shaping not only our biology but also our place in the universe.