• Steven Spielberg
• Alastair Fothergill
• Keith Scholey
• Darryl Frank
• Justin Falvey

• Dan Tapster
• Alastair Fothergill
• Keith Scholey

• Amblin Television
• Silverback Films

Covers theorigin of life and the rules ofevolution, includingnatural selection,adaptation,interaction andspeciation, in addition to an overview of the series. A pair ofSmilodon brothers successfully take down aterror bird,^[a] a motherMaiasaura navigates the nesting grounds to reach her own nest, and a femaleTyrannosaurus and her offspring unsuccessfully attempt to hunt a femaleTriceratops.

In thePrecambrian seas,plankton develops and sets the stage for future organisms.Marine invertebrates slowly evolve and the prehistoric seas are ruled byjellyfish until theCambrian explosion. In the shallow seas of theCambrian era, anAnomalocaris attempts to hunt atrilobite,^[b] but is foiled by thearthropod's hardexoskeleton. By theOrdovician, trilobite armor has become even more advanced to deal with new predators, but is no match for the beaks ofcephalopods such asCameroceras, whileArandaspis, an earlyvertebrate andfish, lives in the shadow of the invertebrates. TheLate Ordovician mass extinction sees a massive global cooling that wipes out a majority of life on Earth, causing many invertebrates to retreat to the deep sea and leaving the vertebrates with a path to dominance. In theDevonian, a family ofDunkleosteus, one of the largest new vertebrates, huntsammonoids^[c] using a vital new adaptation:jaws. Massive blooms of plankton cause globaldeoxygenation, leading to the second mass extinction event: theLate Devonian extinction. However, on land, plants come to dominate and transform the ecosystem, and animals soon follow.

The destabilization of rock bylichen creates the first soil, allowing plants to grow and eventually dominate. In thecoal forests of theCarboniferous, a maleArthropleura follows the scent trail left by a female, and successfully performs his courtship with her. In the water, several younglobe-finned fish^[d] narrowly escape a hungry adult by moving onto land, but one is eaten by an earlyamphibiantetrapod,Anthracosaurus. As the Carboniferous gives way to the drierPermian, some of these amphibious tetrapods develop hard-shelled eggs that are more resistant to desiccation, becoming the firstamniotes. The Permian is dominated byreptiles such asScutosaurus andstem-mammals such asLystrosaurus. A femalegorgonopsid^[e] successfully hunts down aScutosaurus with her saber-like teeth. Massive volcanic eruptions in theSiberian Traps lead to great floods of lava, an atmosphere of noxious chemicals, and rapid global warming, prompting thePermian–Triassic extinction event, the largest mass extinction event in Earth's history, which wipes out almost all life. However, some species such asLystrosaurus manage to survive.

During theEarly Triassic, in the aftermath of the recent extinction, surviving species recoup andLystrosaurus quickly becomes the dominant animal on Earth, reaching an abundance unmatched by any other past or future animal. However, reptiles continue to evolve on the arid margins ofPangaea, and futureLystrosaurus populations find themselves at the mercy of predators such aserythrosuchids, likeErythrosuchus, who are one of the reasons for their extinction. Reptiles diversify and come to dominate both the land and the sea; in a flash-forward to theJurassic, earlysea turtles face predation fromplesiosaurs,^[f] and their hatchlings must avoidpterosaurs as they race to the water. Back in the Triassic, amassive precipitation event brings an end to the Pangaean desert, turning the world lush and green. In theLate Triassic, aPlateosaurus roams these forests, signaling the eventual future dominance of theDinosaurs.

Near the beginning of theEarly Jurassic, heavy volcanic activity during the breakup of Pangaea leads toanother mass extinction. However, the new environments facilitate and supercharge the evolution of the survivors, including the dinosaurs. By theLate Jurassic, and throughout theCretaceous, large dinosaurs of all kinds have evolved. AnAllosaurus unsuccessfully hunts forDiplodocus hatchlings during a rainstorm at night.Flowering plants evolve and revolutionize life on Earth, as numerous lineages of insects adapt to pollinate them while other lineages evolve to feed on these pollinators, and by the Cretaceous, there are more species on the land than in the ocean for the first time. During theEarly Cretaceous, the evolution offeathers benefitstheropod dinosaurs, such asDeinonychus, which hunt in packs, and one of which manages to take down anArkansaurus. Tectonic changes in theLate Cretaceous create shallow seas that increasingly isolate landmasses from one another.Ornithischian dinosaurs, such ashadrosaurs, likeMaiasaura, develop jaws with the ability to chew the newly-evolving plants and the ability to travel in massive herds. Meanwhile, early mammals also take advantage of the diversifying plants and evolve complex behavior as well. A maleTyrannosaurus successfully courts a female.

On the last day of the Cretaceous,Edmontosaurus,Triceratops,Tyrannosaurus,Alamosaurus,azhdarchid pterosaurs and a plesiosaur go about their daily lives just before anasteroid the size ofMount Everest crashes into Earth, causing theCretaceous-Paleogene extinction event.Megatsunamis, burning ejecta from the impact, an overheated atmosphere, andacid rain wipe out a majority of life on Earth, bringing to an end the reign of non-avian dinosaurs and destabilizing the marine food web. Abyssal scavengers and insects survive by feeding on the dead organisms. Some small species of reptiles, amphibians, fish, birds and mammals manage to survive the impact from below the ground and via eggs laid in the ground. These survivors are said to follow in the dinosaurs' footsteps to take their places in taking over the world. A flashback to the Jurassic shows the origins of flight as a femaleAnchiornis uses her gliding abilities to evade a juvenileSinraptor. Despite theimpact winter, the adaptations ofconifers to the cold allow them to dominate the northern latitudes shortly after impact. Meanwhile, flowering plants come to dominate thetropics, formingtropical rainforests, the most biodiverse ecosystem on Earth. By theNeogene, the plains ofSouth America are dominated by the giant terror birds,^[g] which hunt mammals, such asTheosodon. AsAustralia moves north,coral reefs dominate theArafura Sea, serving as centers of diversification for marine life.Seabirds spread across the planet to take advantage of the wealth of prey. Despite the success of birds, it's the mammals that dominate the Cenozoic, as shown by aSmilodon killing a terror bird.

In a flashback to the Jurassic, early mammals^[h] live in the shadow of the dinosaurs, both day and night. Following the K-Pg mass extinction, they quickly rebound and diversify, and follow in the dinosaurs' footsteps in taking their places to dominate the planet. However, in the middle of thePaleogene, the separation ofAntarctica and South America drives a global cooling and drying event, leading to new adaptations in mammals such as large sizes. A maleMegacerops, one of these new giant mammals, unsuccessfully spars with a rival male over a female. The drying trend from Antarctica's separation continues and leads to the replacement of forests withgrasslands over a fifth of Earth's area, leading to theextinction of many mammals. Surviving grazing mammals evolve specialized adaptations to process grass. In earlyQuaternary South America, a curious youngSmilodon investigates a herd ofDoedicurus and attempts to prey on a juvenile, but is warded off by their tails. TheHimalayas are shown as an example of major geologic changes during the Cenozoic. Mammals conquer both the sky and the sea; in a flashback to the Paleogene, aMaiacetus, a semiaquatic earlywhale ancestor, evades the giant sharkOtodus. As the planet cooled, the descendants ofMaiacetus would evolve into the largest animals ever known: the whales. The cooling intensifies, plunging the planet into anice age and leading to the dominance ofa new type of mammal.

Near the beginning of the Quaternary, changes in Earth's orbit, currents, and atmosphere lead to the ice age. By the middle of the Quaternary, thetundra-steppe circles the northern latitudes south of the ice sheets. On their migration through the steppe, a herd ofwoolly mammoths is ambushed by a pride ofcave lions, who successfully take down a subadult individual member. A drying trend leads to the expansion of deserts south of the tundra-steppe, and the rainforests of Africa are almost entirely replaced withsavanna. At the end of the glaciation, the ice sheets melt as the Earth's orbit shifts again and the climate warms. In North America, massiveproglacial lakes form from the melting, and one such melting event leads toimmense floods that carve a path across North America, but rapidly recede. The climate stabilizes and the world greens over in thecurrent epoch, allowing for a recovery of forests and wetlands. Many megafauna worldwide aremysteriously driven to extinction, which allowsbison to dominate theGreat Plains, where they are killeden masse inbuffalo jumps by earlyhuman hunters, who had previously contributed to the megafaunal extinctions. Humans developagriculture and give up thehunter-gatherer lifestyle, leading to the formation ofcomplex society andcivilization, and eventuallytechnology. Humanity's dominance threatens the balance of Earth throughhabitat destruction andclimate change, leading to the potential for asixth mass extinction, which can only be halted through a concerted effort from humanity. However, Freeman notes that no matter what future awaits the Earth, "life has always found a way",^[i] as a dragonfly metamorphoses and flies through a lush,post-apocalypticLondon.