Natural selectionThe process by which those individuals which are best fitted for their environment survive at the expense of those which are less well fitted. This helps the survival of the species as a whole, as those individuals which have disadvantageous characteristics are 'selected against'. Natural selection is a basic mechanism of evolution as it can lead to speciation by favouring a mutation when it introduces particularly advantageous features.
Search Bird Dictionary
From Peter Weaver's Birdwatcher's Dictionary
Copyright © 1981 by Peter Weaver