Lamarck's theory states that characteristics acquired in an organism's lifetime can be passed on to any of its offspring. For example, if an individual works out and gains a more fit and bulkier appearance, then by default that individual's offspring will inherit a fit and bulkier appearance regardless if they work out or not. Darwin's Theory of natural selection accounts for survival and reproduction of an organism, based on their phenotype and genotype compared to their environment to increase or decrease the survival and reproduction of that organism. There is more support for natural selection, because we can see, we clearly do not inherit traits such as hair length, accents, etc from our parents.
