1/ How did life begin?
Abiogenesis is the idea that life arose from non-living chemistry on early Earth — step by step, not all at once.
Understanding these steps helps explain why life is the expected outcome of the right conditions.
2/ Early Earth Context
Earth 4 billion years ago wasn’t a calm blue world. It was a high-energy chemical laboratory — lightning, volcanoes, intense UV, and oceans full of reactive molecules. The environment constantly pushed chemistry forward.
3/ Formation of Simple Organics
When energy hits the right ingredients, simple organic molecules form easily.
We’ve replicated this in labs: spark discharges, UV light, and mineral surfaces all drive the creation of amino acids and basic carbon compounds.
4/ Increasing Molecular Complexity
Once simple molecules exist, they start interacting. Wet–dry cycles, mineral surfaces, and heat all promote bonding.
Over countless cycles, chemistry naturally drifts toward more complex, information-rich molecules.
5/ Why RNA Matters
Before DNA and proteins, early life likely relied on molecules that could both store information and catalyze reactions. RNA fits that role beautifully — and in modern cells, it still carries out ancient catalytic tasks.
6/ The Breakthrough: Replication
Life requires replication, but it doesn’t need perfection at first. Early replicators probably copied themselves poorly, but “good enough” to let variation creep in — and variation is the fuel of natural selection.
7/ Chemical Natural Selection
Even before cells existed, chemical systems competed. Some used energy more effectively, persisted longer, or copied with fewer errors. Chemistry doesn’t need intent — natural selection emerges anywhere replication + variation exist.
8/ Replication + variation = competition.
Systems that were better at surviving and making copies outcompeted others.
Natural selection began long before the first cell existed.
9/ Do scientists have every step solved? No. But we’ve recreated many ingredients in the lab: amino acids, nucleotides, lipid bubbles, simple replicators. Nothing requires magic — just chemistry, energy, and deep time.
10/ Abiogenesis doesn’t compete with evolution — it precedes it.
Chemistry → self-replication → selection → cells.
Once the first cell existed, evolution reshaped life endlessly.
Want to explore more? See the reference card below.
11/ Overview Sources
@LyingWrongAgain let me know how I did in creating a simple overview?
Share this Scrolly Tale with your friends.
A Scrolly Tale is a new way to read Twitter threads with a more visually immersive experience.
Discover more beautiful Scrolly Tales like this.