Mailund on the Internet: Heads or tails and reliable alignments
In this paper they analyse the quality of multiple sequence alignments in an extremely simple manner: They first align the sequences left to right, then reverse them to essentially align them right to left. Unless the alignment algorithm has a preferred order of symbols, you’d expect to get the same alignment going left to right as right to left.
Not always, of course: if the algorithm is based on oligonucleotides or such, then the order matters, but in many cases it doesn’t.
Greg Laden: Genetics of Behavior: Fire Ants
Solenopsis invicta, a fire ant, can have colonies with a single reproductive queen (these are called mongyne colonies) or a colony wit multiple reproductive queens (called polygyne colonies).
In mongyne colonies, all individuals have a particular allele for one gene. The gene is General Protein-9 (Gp-9), and the allele is the B-like allele.
Polygyne colonies contain individuals with both the B-like allele and the b-like allele (case matters!). This has led to the suggestion that the presence of b-like is necessary and sufficient for the rise of polygyne colonies.