| Popis: |
Evolutionary studies suffer of the impossibility of directly observing events that occurred far back in time, on a temporal scale much greater than human life. In our paper we describe and discuss the approaches that different branches of natural sciences have adopted to overcome this inherent and unsurpassable difficulty. We, for instance, explain how chemical features of geological stratigraphy can be used to deduce the conditions in which they formed, using known chemical and physical processes as models. We provide examples of how structural and compositional similarities are used by molecular biologists to infer ancestral traits. We describe how ancient DNA can be used to determine changes in genetic structure of organisms over evolutionary times. We provide instances of reconstruction of paleoenvironments to investigate the relationship between organismal functions and ecosystems in remote times. All these approaches allow to circumvent the unobservability of the past through rigorous approaches and solid assumptions, which, although they may not satisfy a strict Galilean method, constitute a scientifically sound way to investigate the biological past. |
