The original question was whether modern biology might be helpful in understanding rebirth. I think we have to answer this with: probably not. The reason is that biology is purely concerned with physical processes. Heredity could be seen as an instance of physical rebirth at the gene level. Individual genes clearly span multiple life times in the sense of multiple organisms. In case of mitochondrial DNA -since it is passed down unchanged by the mother- it could even be said that rebirth occurs at the level of chromosomes. But genes and mitochondrial DNA are also subject to impermanence due to mutation; in fact this is what makes evolution possible in the first place. Richard Dawkins' book The Selfish Gene gives a fascinating account of this perspective. According to the selfish gene idea, phenotypes are nothing but "lumbering robots" that perform survival functions for the benefit of genes to help them propagate. It's surely an interesting view, but I doubt it has much to do with the Buddhist idea of rebirth.
Consciousness research is perhaps more likely to shed some light on the Buddhist understanding of rebirth. I already mentioned the investigation of PLEs, but the study of near-death experiences (NDE) is likewise relevant to the topic, because NDEs provide a glimpse on what happens when the physical (human) body dies. During the last 50 years, ambulances and modern medicine made it possible for many people to escape death and live on to tell the story. The first case studies of NDEs were published by E. Kübler-Ross, R. Moody et al in the 1970s. Since then a large amount of reports and studies with thousands of cases have been collected, more recently by B. Greyson, M. Morse, S. Parnia, P. v. Lommel and others. Most people who had an NDE, as well as many doctors came to the conclusion that experience continues after death. NDEs cannot be considered conclusive evidence for continuation, since people did come back after all, and there are a number of complicated neurological issues to consider, but they are at least suggestive of continuation.