If it were true, all organisms would be complex and simple organisms would disappear
It does not account for genetic mutations known to affect physical traits
Explanation:
Lamark's theory of evolution is that changes in the organism's physical form during its lifetime can be passed on to its offspring. In other words, he believed that children can inherit acquired characteristics from their parents.
The classic example is that he believed giraffes evolved long necks because they would stretch upwords to eat leaves from tall trees, elongating their necks, and then would pass on a longer neck to its children. Or in humans, that a body builder would make a muscular child because of their intense training!
There are a few problems with this theory:
If we believe this theory, organisms would always be getting more and more complex and 'improved', so simple organisms would disappear.
We know that changes to the DNA influence inherited physical characteristics, not simply continued use
