Figure 2
From: Species and gene divergence in Littorina snails detected by array comparative genomic hybridization
aCGH hybridization signals in Littorina saxatilis (average of 24 individuals). Frequency histogram shows distribution of log-2 normalized and centred signals (zero corresponds to overall signal average); colour curves – a fitted mixture of three normal distributions from mixtools R package. Red curve – low signals, blue curve – normal signals (single-copy genes), green curve – high signals due to multiple gene copies.