Master Timeline
2,600 Generations Ago (from 2020 CE) Long before the sails of European explorers dotted the horizon, the Australian continent witnessed the arrival of its first human inhabitants. Archaeological evidence, such as ancient tools and cave art, suggests that people arrived in Australia at least 65,000 years ago, marking one of the earliest known human migrations […]
The Settlement of Australia Read More »
13.8 billion years ago, space itself began expanding and cooling, setting the stage for particles, atoms, stars, galaxies, planets, life, and us.
Big Bang Expansion Read More »
About 3.85 billion years ago, the RNA world resembled a molecular wild west: replicators drifted. When chemistry favored a structure, it binded.
About 3.9 million years ago RNA-based protocells evolved. Likely with a mix of random DNA experiments.
Assembly of Protocells Read More »
Alongside or following the chemical evolution of organic molecules, the formation of prebiotic microenvironments, such as hydrothermal vents or warm little ponds, provided niches where concentrations of organic molecules could interact. These environments could have been crucial for the assembly of complex organic molecules and the initiation of catalytic cycles.
Formation of Prebiotic Microenvironments Read More »
While the 4.4 billion years ago is a guess as to when these processes might have started, the 4.1 billion years ago guess is a better representatoin of current understanding on when the needed building blocks of life evolved. Before the appearance of self-replicating molecules, there was a crucial phase of chemical evolution where simple
Chemical Evolution of Organic Molecules Read More »
About 4.2 billion years ago, chemical reactions in high temperature environments start replicating. Not life, just replication.
First Life: Self-Replicating Molecules Read More »
The formation of cellular membranes represents a pivotal development in the pre-life world, enabling the creation of defined boundaries for primitive cells. These membranes, likely formed from simple lipid bilayers, provided a controlled environment for chemical reactions and played a critical role in the emergence of the first cell-like structures, distinguishing them from their surrounding
Cellular Membranes Read More »
Metabolism-First life theories suggest life began as a series of self-sustaining chemical reactions trapped in rock pores about 4.1 billion years ago.
Metabolic Pathways Read More »
In evolutionary order, reproduction systems came first; bodies came later. Around 1.1 billion years ago, some single-celled eukaryotes evolved gamete specialization. Instead of two similar cells fusing, one became small and motile (sperm-like) while the other became larger and nutrient-rich (egg-like). These were not separate organisms but reproductive forms of single-celled life. Hundreds of millions
Oogamy: Early Gamete Specialization Before Animals Read More »
An example of early live birth is the protomammal Kayentatherium, Jurassic period. The switch to live birth in mammals, including marsupials and placentals, evolved from a common ancestor.
Mammals: First Live Births Read More »
The amniotic egg evolved in the first amniotes, which evolved into today’s reptiles, birds, and mammals.
Amniotes Emerge: Amniotic Eggs Read More »
The evolution of egg-laying evolved before fish. It is thought to have developed with or shortly after the emergence of the first multicellular animals, around 640 million years ago. Kingdom: Animalia > Phylum: Porifera (sponges) and Cnidaria (jellyfish, corals, etc.)
First Animal Egg Layers Read More »
All life today are either Prokaryote or Eukaryote. Around 2 billion years ago, Eukaryotes evolved from Prokaryotes. The evolutionary leap to eukaryotes introduced cells with a nucleus and membrane-bound organelles, a complex architecture derived from prokaryotic predecessors through endosymbiosis. This process, crucial for eukaryotic evolution, involved the incorporation of prokaryotic cells into the cytoplasm of
The First True Eukaryotes Read More »
Prokaryotes are nucleus-free cells that include both bacteria and archaea — the two lineages that split shortly after LUCA.
76,000 Generations Ago Homo erectus is a direct ancestor of modern humans and represents a key point in human evolution where evidence of a truly omnivorous diet becomes clear, including the use of tools for hunting and processing both plant and animal foods. This species shows significant brain enlargement and other adaptations indicative of complex
Homo erectus: A True Omnivore Read More »
By about 280 million years ago, Dimetrodon was one of the best-known predators of the Early Permian. It stalked rivers and floodplains alongside caseid synapsids, large amphibians like Eryops, and a landscape of Calamites, Sigillaria, ferns, and early seed plants.
Early Complex Sentience Emerges: Dimetrodon Read More »
Morganucodon was an early mammaliaform from about 200 million years ago. Crown mammals emerged from within this group about 170 million years ago.
First Mammaliaforms: Morganucodon Read More »
Plesiadapis, a proto-primate, is an example of a fruit-insect eater likely similar to our direct-line ancestors around this time.
Plesiadapis: First fruit-insect eaters. Read More »
30 Phil, Chapter 17, Alhazen, Touchstone 42: Senses. How we perceive an external world starts to become clear about 1020 CE. Since Alhazen and his pioneering work around 1020 CE, we have made significant advancements in understanding our senses. Our direct impressions of the world. Prior to Alhazen, most people on Earth believed in strange
The Five Senses of Humans Read More »
