How to defend evolution

OK, I’ve got this creationist/Intelligent Design person presenting an agrument against evolution I do not know how to answer. Please help. His question:

If we evolved which required millions of years, how did we reproduce during that time to continue the population? He says that the reproductive system also had to evolve which would exceed the life of the species thus ceasing the evoultion.

I am sure there is a good answer to this. Thanks


We evolved from creatures that had already developed reproductive systems. It’s not as if every new species develops independently, for crying out loud…

The reproductive system changes incrementally as the species changes. I’m not really sure what the conflict is here.

Pre-cells were formed of molecules, such as RNA, which catalyze their own replication. At least partially.

Great answers but be warned: you are quite possibly arguing with a person whose ultimate authority is a self-referential argument. eg; this book must be true because it says it is true. A fallacy but one that is insurmountable when faced with someone who fanatically holds it. Good luck

Ronm9, I think it would be helpful if you could clarify more specifically what your friend’s objections are.

Can you demonstrate that science is true without invoking science? It seems to me that to prove the universe rational, you need to first posit a rational universe. Is science not therefore just as fallacious as the religion du jour?

robertliguori That would make for a good discussion. But I don’t want to hijack this thread for it. If you wish to put it up in a new one though…

One thing you should consider is that even if you don’t know the answer, such an example is not an argument against evolution. Ask him which specific mechanism is allegedly refuted by his query. It is the mechanisms, not the examples, which form the core of evolutionary theory. Our knowledge of how a specific structure or trait evolved is largely dependent on the availability of evidence, frequently from the fossil record. The status of evolutionary theory does not rise or fall on whether we can readily explain each and every observable trait (as a side note, it is interesting how it is expected that, after only about 150 years, scientists should now know everything about how everything evolved, and if something cannot be readily explained, the theories must be false…).

ID capitalizes on these gaps in knowledge by essentially claiming that if we can’t determine how a structure might have evolved through natural selection, it therefore must have been designed. This is why ID is frequently referred to as a “God of the gaps” argument, because it can only apply in those instances where our knowledge is limited; they rarely bring up examples where our knowledge is relativley robust.

Come to the Empirical Philosophy II thread. I’m trying to do just that (albeit rather poorly).

My answer would be to start with single celled organisms and work your way up from there. An Amoeba reproduces by splitting itself into 2 amoebas. AFAIK most single celled organisms dont sexualy reproduce. The higher on the evoulutionary scale you go the more complex the DNA and RNA structures become. This gives way to more specialized tissue groups.
If we go back to the amoeba, they “eat” by flowing around their food and eventualy envelopeing it with in their own cell membrane. Once inside the membrane the food is metabolized. Higher animals, like a dust mite for example have a mouth and seperate organs for digesting food. The farther a long you go the more specialized and unique tissues you wil find. It seems like common sense that if animals develop specialized tissues to eat and digest when compared to an amoeba , that they would do the same thing where reproduction was concerned. Instead of just undergoing cellular division most higher animals engage in sexual reproduction with specialized tissues and cells.

Once you have a mingleing of DNA, like with sexual reproduction, you introduce a posibility to change the next generation. THis is why pretty much all amoebas look the same, but all people look diffrent. Each new amoeba is basicaly a clone of the one that split to make it, where most other animals come from a mingleing of DNA. The mingleing is what gives change and evolution its chance to work.

There is no evolutionary scale.

Damn. Beat me to it. :smiley:

There does seem to be a slight tendency for organisms to become more complex with time, although it’s clearly not generally the case…

The vast majority of life on Earth is made up of microorganisms that live inside the crust and break down minerals for energy. Their sophistication lies in their simplicity, which is probably why there’s so many of 'em.

Ooh… that’s a good counter to creationist arguments! Ask 'em why God made the majority of life single-celled creatures that live miles below the surface. (Mysterious ways my foot…)

What difference would that make?

Because they have absolutely nothing to do to with humanity, yet they dominate the planet.

Even the algae in the oceans is vitally important to the continuance of human life. The rock-eating microbes, in contrast, have no noticable effect on humanity.

Creationism is really just another way to put humanity back at the center of the universe; if not physically, then biologically. The microbes are a reminder that we’re not at the center of anything.

As this has been an ongoing discussion between him and I, I have heard his objections according to the various arguments posted here. So I guess I will just play devil’s advocate here with the objective of learning some things from you guys, plus it will make the discussion more interesting.
First to clarify.
It sounds like we have two classifications for this topic, cells and higher animals. If not please correct.

It sounds like this argument does not apply to cells as they do not reproduce with reproductive systems. If I say this I already hear the response - the statistic of 10 to the 40,0000 power to get the proper sequencing of enzymes/amino acids to produce a cell.

For higher animals. His argument is from one species to another. The definition of science is “observation” and “reproduction”. Science has never observed one species evolving into another, micro-evolution yes.

Then I hear mutations never increase information they just lose so the evolution would not be improved but decline.

Please help.

There are also colonies of single cells which can behave as a unit (see Volvox), as well as symbiotic relationships between cells.

See Observed Instances of Speciation and Some More Observed Speciation Events from

See The Evolution of Improved Fitness and Extant Variation. Also see How to Measure Information. These should provide some useful information regarding…information.

Also, consider this: if a point mutation in gene A leads to gene B, what information is lost? Now, suppose a second mutation later occurs in the opposite direction: B -> A. By the logic of “all mutations must result in lost information”, one must therefore conclude that the second gene A has less information than the first gene A!

Vorlon wrote:

So what? Pay attention to Finch and the way he argues his points. This is a teleological issue, not a theological one.

I think, of all the creationist fallacies, this is the one I dislike the most.

You’ve just given me the odds that, by stringing nucleic acids together randomly, I will assemble the 130,001st cell from the left in Saddam Hussein’s pancreas. It’s as if this is the only cell that could ever exist or ever matter.

If you accept even one other cell in the same man’s body, you double the chances… If you accept any cell in his body… or any cell in any other human’s body… or any cell in any other animal’s body… or any cell in any hypothetical animal’s body (e.g., all the dinosaurs that might have come into existence if the comet hadn’t wiped 'em out)… the chances increase astronomically.

Geeze. The same “proof” shows that snowflakes can’t exist.