Every ancestral grade from LUCA to Homo sapiens — a four-billion-year sequence of begats, reconstructed as far as the evidence allows.
+++ PHYLOGENETIC RECONSTRUCTION LOADED +++ 52 ANCESTRAL GRADES ON FILE +++ 4.2 BILLION YEARS TRAVERSED +++ DIRECT ANCESTRY: UNVERIFIABLE BY DESIGN +++ PROXIES SUBSTITUTED WHERE THE RECORD FAILS +++ TWO MERGERS DETECTED, ONE ARCHAEAL, ONE NEANDERTHAL +++ THE CHAIN HAS NEVER ONCE BROKEN +++ NEITHER HAS YOURS +++
Lineage Readout
STAGES:52 CHARTED
SPAN:4.2 Ga
GENERATIONS:~1017
BREAKS IN CHAIN:0
LOCAL TIME:--:--:--
> tracing lineage_
Read This First
The route is solid; the stops are not. Phylogenetics pins down the branching order — the nested chain of "we are a kind of X, which is a kind of Y" — with very high confidence. But almost no named fossil can be shown to be a literal ancestor. Fossils are sampled from a bush; direct ancestry is close to untestable.
So each stage below is an ancestral grade: a reconstructed population defined by what it had evolved. The fossil listed is a proxy — the best-known organism that looked roughly like our ancestor did at that moment, usually a cousin rather than a grandparent. Two badges track this separately: one for the branching position, one for the proxy.
The deep end isn't a chain at all. The eukaryotic cell arose from a merger of an archaeal host and a bacterial endosymbiont, so at least two ancestries braid together there — and before LUCA, rampant gene swapping means "ancestor" describes a gene pool, not an organism.