It's not clear precisely what role scientific evidence plays when someone chooses between young-age creationism and evolution over billions of years. Certainly no one can approach the issue dispassionately; we would all have to declare an interest if we were called upon to examine the evidence objectively. But still, we can try to think about what each model would (perhaps) imply, and try to see whether the data fit more comfortably with one or the other, even if we are honest about whether or not we would change our minds if the evidence seemed to point away from what we currently believe.
There's plenty of evidence that fits more comfortably with billions of years of evolution than with a young-age creation model. For example, looking at the evidence, it seems that a huge amount of radioactive decay has taken place. If the bulk of this took place during the Flood (as current young-age models would claim), it would have generated enough heat to "potentially vaporize the earth's oceans, melt the crust, and obliterate the surface of the earth", according to young-age creationist Larry Vardiman. Models involving billions of years don't have this particular problem.
But there also appears to be plenty of evidence that fits more comfortably within a young-age framework.
The Carrying the Creation Torch day in Leicester yesterday featured four talks focusing on the scientific evidence for young-age creation, sandwiched by two talks by David Catchpoole of Creation Ministries International (CMI), focusing on the theological side of the issue. (I missed both of those talks.)
Dominic Statham, speaker for CMI, spoke about Migration after the Genesis Flood. In the standard evolutionary framework, it seems that a lot of biogeography (the geography of plants and animals) is best explained by migration by sea. This fits in with the Flood, which would have left lots of floating rafts in the oceans. Interesting stuff, presented clearly and fairly.
Stuart Burgess next, on Hallmarks of design 12 years on. Burgess is a professor of engineering design, specialising in spotting excellent engineering solutions in living things, and then copying them. The existence of "irreducible mechanisms", such as the four-bar mechanism in the knee, is a challenge to evolutionary models, but fits comfortably in young-age creation models, in which complex or optimum design is no surprise.
Philip Bell, from CMI, spoke on Let the Rocks Speak: Evidence for the Flood from Fossils and Geology. Large-scale geological features fit the young-age view better than the long-age view. Vast sedimentary rock layers, spanning continental scales, speak of continental-sized catastrophic processes. There seems to be very little time between layers (no signs of erosion on the lower layer where they join), rapid burial of fossils, folding of (necessarily soft) rock layers on huge scales, and features such as flat-topped mountains and water gaps that would be expected to be produced by the receding waters of a global flood.
Finally, Vij Sodera, a surgeon, gave a talk entitled, Biology agrees with the Bible. I think he overstated his case, but he made it convincing that it is very difficult to imagine how the mammalian diaphragm or the human big toe could have evolved through a step-by-step process, in which each step would be viable and convey some advantage (or at least no major disadvantage).
All in all, a stimulating day. My only major concern is that someone could have come out at the end of the day not appreciating that the young-age creation model still has major unsolved problems. I'm not surprised about that, but I would love it to be the case that people on both sides of the issue didn't feel threatened by that sort of thing. Just because a scientific theory has huge gaping holes in it (as most of them do), that doesn't mean the theory is wrong (pace Popper, and most protagonists in the creation/evolution debate). Nor does it mean people should abandon that theory. It just means more research is needed.