convergence (redirected from Convergance)

convergence /con·ver·gence/ (kon-ver´jens)

1. in evolution, the development of similar structures or organisms in unrelated taxa.

2. in embryology, the movement of cells from the periphery to the midline in gastrulation.

3. coordinated inclination of the two lines of sight towards their common point of fixation, or that point itself.

4. the exciting of a single sensory neuron by incoming impulses from multiple other neurons.conver´gent

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negative convergence  outward deviation of the visual axes.

positive convergence  inward deviation of the visual axes.

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con·ver·gence (kn-vûrjns)

n.

1. The process of coming together or the state of having come together toward a common point.

2. Such a gathering at a single preganglionic motor neuron of several postganglionic motor neurons.

3. The coordinated turning of the eyes inward to focus on an object at close range.

4. The adaptive evolution of superficially similar structures, such as the wings of birds and insects, in unrelated species subjected to similar environments. Also called convergent evolution.

5. The movement of cells from the periphery of the embryo toward the midline during gastrulation.

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con·verge v.

con·vergent adj.

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convergence

1. a moving together, or inclination toward a common point; the coordinated movement of the two eyes toward fixation of the same near point.

2. the point of meeting of convergent lines.