Is anisogamy of evolutionary significance?
Yes. Anisogamy is where the male and female gametes are significantly different, particularly in size. In sexual species, the next generation will only be formed if the male gametes fuse with the female gametes. The male gametes (eg. sperm) are very small, so more of them can be produced and they can be spread widely to fertilise female gametes. The female gametes (e.g. ova) are large because less of them are produced, because they need to be found by the male gametes and because they often contain nutrients required for early development. Anisogamy can be seen as two equally successful strategies for the proapagtion of offspring, as can the evolution of the sexes itself.