>>23955745“Over time” isn’t a smokescreen. It’s shorthand for known, observed mechanisms. Chromosomes are added, removed, or rearranged by specific processes: Robertsonian fusions and fissions, unequal crossing-over, duplications, deletions, inversions, and polyploidy. These are documented in humans, animals, and plants right now.
A chromosomal change occurs in an individual, that individual reproduces (often with reduced but non-zero fertility), the variant spreads or disappears via population genetics (selection + drift), and if populations become reproductively isolated, speciation follows.
We directly observe populations with mixed chromosome counts, transitional karyotypes, and fixed changes across related species. Human chromosome 2 even preserves the fusion scar (telomeres + inactive centromere), exactly as predicted.
Calling this “not explained” just means you’re ignoring the mechanisms either because they aren’t instantaneous, you don’t understand them or you’re being intentionally obtuse. Biology operates at population scale, not a single birth event.
