Reconstructing the heart – Arun Holden (p.15)

Last century, papers in The Journal of Physiology described experiments on whole animals, or on isolated organs; current papers are more likely to describe experiments on isolated tissues or cells, or even membrane patches.

This reflects the reductionist tendency in modern biology, whereby a biological question is only perceived as being scientific if it can be answered in terms of molecular structures. Given the right tools, even a child can break apart a complicated machine into its components; putting them all back together is more difficult.