Well, one of the things they say is that there are no transitional fossils.

This is wrong on three counts.  First, they don't even understand the basic principle of evolution.  Every fossil is a transitional fossil, for every organism is technically in transition.  Any human with children could be the father or mother of a new species, but nobody will know until the new species is here.

The second thing ties into the first.  Species are only identified in reverse, and the category itself is a bit nebulous.  It's true that we can divide up animals according to who they mate with, but that's not entirely accurate, for different species can sometimes mate.  They just don't usually do it in the wild.  In any case, it's like the first point.  There is never a point in evolution where Homo erectus gave birth to a Homo sapien.  There were thousands of generations of creatures who were kind of like erectus and kind of like sapiens, to some degree or another.  At some point, so much of erectus had been removed from the gene pool that we could rightly be called human, but this kind of change can only be identified well after it has occurred.  It's way too slow and subtle to recognize in one lifetime.

The third thing, then, is that we have TONS of transitional fossils.  We have museums full of pre-human skulls, each showing slightly different degrees of human-like qualities.  We have a great transitional record of the horse.  The thing is, for any two fossils that you show a creationist, they'll point out that there are still gaps to be filled.

Well, duh.  If there were no gaps, they'd be the same species, wouldn't they?

Let's see... what else?  The Second Law of Thermodynamics.  They say that order cannot come from chaos because of the SLT.  The Law does say that things tend towards chaos, but that's only in a closed system.  In other words, when there's a set amount of energy, entropy will result.  As it turns out, the earth is not a closed system.  Here's one of my favorite quotes from a Creationist...

So, awesomestnerd... have you ever noticed that big yellow circle in the sky???

One of the biggest ones is obviously,"Evolution is just a theory omg lolz." Ya? Then why aren't you busy spinning off into space you silly theist?After all, gravity's just a theory. The correct answer would be along the lines that 'theory'  has different meanings in layman and scientific terms. It can be both a theory and fact.

You might want to read these:

http://www.rationalresponders.com/warning_gravity_is_only_a_theory

http://www.rationalresponders.com/comment/reply/10532

Also,could you post a link to this 'chic tract.'I've heard about it but can't find it. What is it?

Well first of all, I think that is an awesome idea, to make anti-chic tracts!

I would definitely start out with Hamby's fossil suggestion, as that's a little easier to put into comic form than some of other aspects of evolution.

But I had another idea for debunking Christian lies.

A lot of times, they say that evolution is impossible because there is no way for a "gain of information" to occur. Now it's never exactly clear to me what is meant by this, but it is clear that they don't understand mutation is the basis of evolution, and that they have no clue how the mechanism of mutation works.

I think what is meant by their "gain of information" statement is: How do you get a single-celled organism to gain genes for arms and legs and eyes and stuff?

First you need to know the general structure of DNA: the backbone is formed by a phosphate and sugar (deoxyribose), and there are four nucleotide bases that are linked by hydrogen bonds: adenine, thymine, cytosine, and guanine. A and T always pair with each other, and C and G always pair with each other.

Well, every time a cell divides, the whole genome must be copied so that the daughter cell can have its own separate genome. The duplication process is incredibly accurate, but mistakes do occur.

There are five types of genetic change that can lead to evolution:

1. Point Mutations: These occur within a gene. There are a few types of point mutations that can occur.

a) Substitution - one base is changed to another (i.e. A is copied as C)
b) Deletion - one base is deleted
c) Insertion - one base is added

Because every 3 bases (known as a codon) codes for an amino acid (the components that make up proteins), these can change the amino acid coded for, which can affect the overall protein produced. For instance, CTT codes for leucine. A substition could change it to GTT, which would make it code for valine. This might make an ineffective protein. On the other hand, even if CTT is changed to CTC, this still codes for leucine, so the mutation is neutral. Most of the amino acids have several corresponding codon sequences so that it is more likely that a point mutation will be neutral. (you can find codon/amino acid tables online - i certainly don't have all the sequences memorized, heh)

If this codon is in the sequence, TGT CTT CAA, this codes for cysteine leucine glutamine. If there's an insertion:

TGT CAT TCA A.. - this shifts the "reading frame" over, so now the sequence codes for cysteine histidine serine. This can totally change the protein that is made up of the amino acids. The same can happen with a deletion to the original sequence:

TGT TTC AAT... will now shift the frame over so the sequence codes for cysteine phenylalanine asparagine.

(the whole frameshift thing is actually a lot easier to convey through pictures than through words... in my opinion)

2. Gene duplication - an entire gene can be duplicated. Sometimes this even happens to the entire genome! There are certain species of frog that are the same as another species of frog, except that they have an extra copy of each gene (or sometimes even more copies). The same has also been observed in certain types of fish. The duplicated genes are then free to mutate on their own, so they could eventually end up with functions different from the original gene.

3. Gene deletion - sometimes one or more genes can be lost if a chromosome breaks or if the appropriate proteins fail to repair DNA.

4. Exon shuffling - Two existing genes can be broken and rejoined to make hybrid genes that have half of each gene. A lot of times this happens with "junk" DNA in humans, and sometimes a functional gene actually results.

5. Horizontal gene transfer - This really only happens with bacteria. But this is when a piece of DNA is transferred from the genome of one bacteria to another, right through the cell membrane. This is how drug-resistant bacteria can form - genes that confer resistance to a particular antibiotic can even be transferred from one species of bacteria to another, because the genetic code is consistent.

As we see "information gains" actually happen all the time in evolution, and there are several mechanisms that allow for it to happen. These happen at a very slow rate - for instance, the chance of a point mutation occurring in humans is 0.1 nucleotide changes per every 10^9 nucleotide pairs - pretty damn accurate. But over large spans of time, these tiny changes can accumulate and eventually create a larger change.

OK, I could go on about evolution all day, lol. But I think that's more than enough to get started on, if you choose to decide go with this particular idea.

Anyways, good luck with your idea - can't wait to see the final products.