Civilization Research CardsHuman Origins to Interstellar Life

Real basis

• The Taung Child: A child's skull showed that human ancestors came from Africa and learned to walk upright first, with bigger brains coming later.

  Source: Dart, Nature 1925, "Australopithecus africanus: The man-ape of South Africa"

• Mitochondrial Eve: The mitochondrial DNA of all modern humans can be traced back to one woman in Africa about 200,000 years ago.

  Source: Cann, Stoneking & Wilson, Nature 1987, "Mitochondrial DNA and human evolution"

• The Neanderthal genome: After sequencing the Neanderthal genome, it turned out that modern humans outside Africa all carry a small part of their DNA.

  Source: Green et al., Science 2010, "A draft sequence of the Neandertal genome"

• Denisovans: From the DNA of a single finger bone, a group of ancient humans previously unknown was discovered.

  Source: Reich et al., Nature 2010, "Genetic history of an archaic hominin group from Denisova Cave in Siberia"

• Homo sapiens from 300,000 years ago: Fossils from Morocco pushed back the history of Homo sapiens by about 100,000 years and suggest they originated across all of Africa rather than at a single site.

  Source: Hublin et al., Nature 2017, "New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens"

• The oldest stone tools: These stone tools predate the genus Homo, showing that toolmakers were not necessarily “human.”

  Source: Harmand et al., Nature 2015, "3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya"

• Laetoli footprints: A line of footprints in volcanic ash proves that early hominins were already walking upright over 3.6 million years ago.

  Source: Leakey & Hay, Nature 1979, "Pliocene footprints in the Laetolil Beds at Laetoli, northern Tanzania"

• A campfire a million years ago: Ash and burned bones in Wonderwerk Cave, South Africa, are evidence that early humans used fire inside the cave.

  Source: Berna et al., PNAS 2012, "Microstratigraphic evidence of in situ fire in the Acheulean strata of Wonderwerk Cave"

• The oldest cave painting: A painting of a pig at least 45,500 years old is one of the oldest known figurative artworks.

  Source: Brumm et al., Science Advances 2021, "Oldest cave art found in Sulawesi"

• The language gene: The FOXP2 gene linked to language underwent special changes in the human lineage.

  Source: Enard et al., Nature 2002, "Molecular evolution of FOXP2, a gene involved in speech and language"

• Lucy's family: Johanson and White placed Australopithecus afarensis, Lucy's species, on the human evolutionary tree.

  Source: Johanson & White, Science 1979, "A systematic assessment of early African hominids"

• The origin of rice: Comparing over a thousand rice genomes showed that cultivated rice originated from wild rice in the Pearl River basin of China.

  Source: Huang et al., Nature 2012, "A map of rice genome variation reveals the origin of cultivated rice"

• Farmers and languages: The expansion of farming populations carried their languages to new places and shaped today's distribution of language families.

  Source: Diamond & Bellwood, Science 2003, "Farmers and their languages: the first expansions"

• Radiocarbon dating: Libby invented a way to measure the age of ancient objects with carbon-14, giving archaeology a “clock.” Nobel Prize 1960.

  Source: Arnold & Libby, Science 1949, "Age determinations by radiocarbon content: checks with samples of known age"

• Electromagnetic field theory: Maxwell unified electricity and magnetism and calculated that the speed of electromagnetic waves equals the speed of light: light is an electromagnetic wave.

  Source: Maxwell, Philosophical Transactions of the Royal Society 1865, "A dynamical theory of the electromagnetic field"

• Special relativity: Time and space are not absolute. A junior clerk at a patent office published four physics-changing papers in a single year.

  Source: Einstein, Annalen der Physik 1905, "Zur Elektrodynamik bewegter Körper"

• Penicillin: Mold that grew by accident in a petri dish killed the bacteria around it, and the antibiotic age began.

  Source: Fleming, British Journal of Experimental Pathology 1929, "On the antibacterial action of cultures of a penicillium"

• Computability: Turing imagined an abstract machine that defined what “computation” is, laying the theoretical basis of modern computers.

  Source: Turing, Proceedings of the London Mathematical Society 1936, "On computable numbers, with an application to the Entscheidungsproblem"

• Information theory: Shannon turned “information” into a measurable quantity, and the bit was born.

  Source: Shannon, Bell System Technical Journal 1948, "A mathematical theory of communication"

• The transistor: One piece of semiconductor can amplify a signal. It replaced vacuum tubes and shrank computers from room-sized to pocket-sized.

  Source: Bardeen & Brattain, Physical Review 1948, "The transistor, a semi-conductor triode"

• The World Wide Web: An internal proposal, which the boss annotated “vague but exciting.” It later became the World Wide Web.

  Source: Berners-Lee, CERN 1989, "Information management: A proposal"

• Searching for interstellar signals: Two physicists suggested listening for alien signals with radio telescopes near hydrogen's 21 cm frequency, launching SETI.

  Source: Cocconi & Morrison, Nature 1959, "Searching for interstellar communications"

• Dyson sphere: A sufficiently advanced civilization might wrap its star, and we could find it through anomalous infrared radiation.

  Source: Dyson, Science 1960, "Search for artificial stellar sources of infrared radiation"

• Scale of civilizations: Sorts civilizations into three types by the energy they can use: planetary, stellar and galactic.

  Source: Kardashev, Soviet Astronomy 1964, "Transmission of information by extraterrestrial civilizations"

• Black holes evaporate: Quantum effects make black holes radiate energy slowly. Black holes are not eternal and will eventually evaporate.

  Source: Hawking, Nature 1974, "Black hole explosions?"

• Warp drive: General relativity allows a “warp bubble” that compresses space ahead and stretches it behind, but it needs negative energy that may not exist in reality.

  Source: Alcubierre, Classical and Quantum Gravity 1994, "The warp drive: hyper-fast travel within general relativity"

• Light sails to the stars: Pushing ultralight light sails with a ground-based laser array could accelerate probes to one fifth the speed of light.

  Source: Lubin, Journal of the British Interplanetary Society 2016, "A roadmap to interstellar flight"

• Where are they?: If alien civilizations were common, they should already fill the galaxy. From this Hart argued that we may be the first.

  Source: Hart, Quarterly Journal of the Royal Astronomical Society 1975, "An explanation for the absence of extraterrestrials on Earth"

• The last chapter of the universe: Worked out the fate of the universe over trillions of years and beyond: stars go out, protons perhaps decay, and black holes finally evaporate.

  Source: Adams & Laughlin, Reviews of Modern Physics 1997, "A dying universe: the long-term fate and evolution of astrophysical objects"

• Leaving the heliosphere: Particle changes measured by Voyager 1 show it has left the realm of the solar wind and entered interstellar space.

  Source: Stone et al., Science 2013, "Voyager 1 observes low-energy galactic cosmic rays in a region depleted of heliospheric ions"

• Seven tons of liquid xenon: About 1.5 km underground, 7 tonnes of liquid xenon waited for dark matter particles and saw no signal, setting the strictest limits so far. What dark matter is remains unknown.

  Source: LZ Collaboration, Physical Review Letters 2025, "Dark matter search results from 4.2 tonne-years of exposure of the LUX-ZEPLIN (LZ) experiment"