Movies of 2X sped up C. elegans as they chemotax toward a point source of 10-2 benzaldehyde. The corresponding clip of worms after exposure to benzaldehyde (10-4) for 80 minutes in the absence of food.
Similarity in the sequence of a protein or nucleic acid or in the structure of an organ that reflects a common evolutionary origin. Molecules or sequences that exhibit homology are referred to as homologs. In contrast, analogy is a similarity in structure or function that does not reflect a common evolutionary origin.