Is there any relationship between the complexity of a fossil and its age?Please give specific examples to explain your answer.

Scientists from the University of Bath (United States)
come up with new evidence, which seem to confirm a new law of evolution: organisms
evolve in general to an increasing complexity. Of course, such a law of evolution would
seem logical if we accept the premise that life began in simple
forms.

As simply as that, in this case it can only be one
direction in evolution: towards a higher complexity. However, nothing prevents the
bodies to return to a simpler form, once a degree of complexity has been reached. Let us
not forget that all bodies which have evolved and survived until today, are complex.
Bacteria for example, are simple forms of life, but they have adapted very well in
today's complex environment.

Of course, there are no rules
without exceptions. An example is bodies living in habitats such as isolated marine
caves. They seem to regress in their evolution towards complexity. Another example is
some species of parasites.

The fossils of the Cambrian
have a high level of complexity, in the layers of Cambrian, fossils being found
easily.They are very numerous and very diversified. Cambrian fauna includes
representatives of all major groups of invertebrates, that still exists today. Species
alive today are easily recognizable, with all their characters, once they are met in the
strata in which they were fossilized. 

Cambrian strata are
exposing a sudden explosion of species. As the Cambrian strata are examined,
strata which are known to be the oldest containing fossil, we discover that many marine
species have existed at the time, very clearly differentiated from one another. The
world of that time was as complex as that of today. Some forms are different from those
of today, while others are very similar, and in some cases, even identical. In the
latter category are blue algae, sponges and marine worms, for
example.