Susan couldn't make the cladograms work.
Three in the morning, her Davis kitchen lit by laptop glow, the house silent around her. Howard had given up at midnight, kissed her forehead, murmured something about the bed being cold without her. She'd barely registered him leaving. The data had her now.
On the screen: phylogenetic trees she'd been building from the expedition data. Each navigation had produced biological observations—species distributions, morphological features, ecological relationships across half a billion years. Standard methods should have organized this into coherent evolutionary trees.
Instead, the trees refused to resolve.
She ran the algorithm again. Same result: polytomies—unresolved branch points where the method couldn't determine which lineages diverged first. Hard polytomies, soft polytomies, entire clades emerging simultaneously from nothing. The data was clean. She'd checked it a dozen times. The problem wasn't noise.
The problem was the data itself.
"Ancestry isn't the organizing principle," she muttered to the empty kitchen. The thought had been circling for hours, never quite landing. If not ancestry, then what?
She pulled up the archive visualizations ARCHIE had generated during expeditions. The lattice rendered in false color, showing information density across temporal coordinates. She'd looked at these a hundred times. But now, with the failed cladograms fresh in her mind, she saw something she'd missed.
…
