[link to r.search.yahoo.com (secure)]


Mosaic evolution is a scientific theory that states traits can evolve independently from each other and at a different rate.

This phenomenon is also the reason not every ancestral species has the same morphological traits.

Another definition is the 'evolution of characters at various rates both within and between species'.

It is a trend that can only be observed at the macro-scale and over thousands of years, as the evolution of different morphological traits can take hundreds of generations to manifest.

There are several known examples in nature.

These include:

The early evolution of bipedalism - walking on two legs - in an early hominid species took place well before there was any significant change in the skull, or brain size.
Evolution of the horse, in which the major changes took place at different times, not all simultaneously.
Sea turtles evolved beaks and shells at around the same time but completely independently. Some species had a beak but not a shell and vice versa.
This led to the modern-day species we see with both features.