Humans from bacteria to amphibian to reptile to mammal....seriously?  However, I have known some humans that remind me of snakes.

Some thoughts on how evolution works...let me say in advance I'm all for dinosaurs, cavemen and fossil records.  I also believe in mutation and gene theory, etc.  However, some of the claims of evolution are summarized below.  To me they seem to be what Mark Twain would have called stretchers!

The earliest known reptiles are so amphibian-like that their assignment to one category or the other is largely a matter of opinion. In this area of life, however, there was no missing link; all the gradations from amphibian to reptile exist with a clarity seldom equaled in paleontology.

Information taken from http://science.howstuffworks.com/environmental/life/evolution/evolution7.htm

Evolution is a set of principles that tries to explain how life, in all its various forms, appeared on Earth. The theory of evolution succeeds in explaining why we see bacteria and mosquitoes becoming resistant to antibiotics and insecticides. It also successfully predicted, for example, that X-ray exposure would lead to thousands of mutations in fruit flies.

Here are three common questions that are asked about the current theory of evolution:

• How does evolution add information to a genome to create progressively more complicated organisms?
• How is evolution able to bring about drastic changes so quickly?
• How could the first living cell arise spontaneously to get evolution started?

According to Carl Sagan in "The Dragons of Eden":

Large organisms such as human beings average about one mutation per ten gametes [a gamete is a sex cell, either sperm or egg] -- that is, there is a 10 percent chance that any given sperm or egg cell produced will have a new and inheritable change in the genetic instructions that make up the next generation. These mutations occur at random and are almost uniformly harmful -- it is rare that a precision machine is improved by a random change in the instructions for making it.

According to "Molecular Biology of the Cell":

Only about one nucleotide pair in a thousand is randomly changed every 200,000 years. Even so, in a population of 10,000 individuals, every possible nucleotide substitution will have been "tried out" on about 50 occasions in the course of a million years, which is a short span of time in relation to the evolution of species. Much of the variation created in this way will be disadvantageous to the organism and will be selected against in the population. When a rare variant sequence is advantageous, however, it will be rapidly propagated by natural selection. Consequently, it can be expected that in any given species the functions of most genes will have been optimized by random point mutation and selection.

Creating a New Species

Imagine that you take a group of Saint Bernards and put them on one island, and on another island you put a group of Chihuahuas. Saint Bernards and Chihuahuas are both members of the species "dog" right now -- a Saint Bernard can mate with a Chihuahua (probably through artificial insemination) and create normal puppies. They will be odd-looking puppies, but normal puppies nonetheless.

Given enough time, it is possible to see how speciation -- the development of a new species through evolution -- could occur among the Saint Bernards and the Chihuahuas on their respective islands. What would happen is that the Saint Bernard gene pool would acquire random mutations shared by all of the Saint Bernards on the island (through interbreeding), and the Chihuahuas would acquire a completely different set of random mutations shared by all of the Chihuahuas on their island. These two gene pools would eventually become incompatible with one another, to the point where the two breeds could no longer interbreed. At that point, you have two distinct species.

Because of the huge size difference between a Saint Bernard and a Chihuahua, it would be possible to put both types of dogs on the same island and have the exact same process occur. The Saint Bernards would naturally breed with only the Saint Bernards and the Chihuahuas would naturally breed with only the Chihuahuas, so speciation would still occur.

If you put two groups of Chihuahuas on two separate islands, the process would also occur. The two groups of Chihuahuas would accumulate different collections of mutations in their gene pools and eventually become different species that could not interbreed.

The theory of evolution proposes that the process that might create a separate Chihuahua-type species and Saint Bernard-type species is the same process that has created all of the species we see today. When a species gets split into two (or more) distinct subsets, for example by a mountain range, an ocean or a size difference, the subsets pick up different mutations, create different gene pools and eventually form distinct species.

Is this truly how all of the different species we see today have formed? Most people agree that bacteria evolve in small ways (microevolution), but there is some controversy around the idea of speciation (macroevolution).