**Author details**

**8. Concluding remarks**

670 Regenerative Medicine and Tissue Engineering

for the imagination of the authors.

**9. Summary**

after birth.

cation in complex organisms.

a gravitational environment.

This text traces its origin in the lectures given to students, in the discussions held with PhD students and in some years spent in cardiovascular research, and more precisely, in hemato‐ poietic adult stem cells. All it has been then placed in an evolutionary perspective that has helped to give the text a teleological perspective; however, being the territory of the origins and evolution of life on earth almost without scientific evidences, the text leaves wide space

The text was then carefully reviewed to avoid repetitive forms that relate to citations; unfortu‐ nately, in some cases, this may have led to borderline syntactic forms, so we apologize to our readers. Finally, the images, with some exceptions, are an attempt to conceptualize the evolution and the adaptive processes and, therefore, do not have a data base to which to refer, however, we believe that they can illustrate complex phenomena not yet completely known.

In the complex interplay between organization of the living matter, natural selection and adaptation, mammals have evolved with limited or no re-generative capabilities of the heart

The reasons for this apparent flaw is far from being understood, however, they are closely related to the concept of organization and allocation of resources in a hierarchically struc‐ tured multi-cellular organism with an evolved system of transport and communication, such as the circulation of blood. In humans this flaw may not have been a problem for thou‐ sands of years until, in the twentieth century, the increase in life expectancy has given rise to diseases generally less frequent in the first three or four decades of life. Therefore, the signif‐ icant increase in morbidity and mortality related to cardiovascular disease, seen mainly in Western countries in the last years, has brought to the foreground the problem of cardiac damage and of its repair. In order to develop new therapies for cardiovascular damage aimed at reawakening and, possibly, expanding the limited re-generative capabilities of the heart is necessary to reconsider the basic concept on adaptation and functional reserve allo‐

In this regard, the demonstration of a temporary re-generative window in the post-natal heart of higher vertebrates may provide an opportunity to investigate when, why and how

Therefore in this chapter we will consider this window that appears to be the last post-natal re-generative "chance" of the heart and try to place it in the general context of the adaptation by assuming that its meaning is, at least in part, related to the cardiovascular adjustment in

the re-generative capabilities are self-limited in some organs by the genetic program.

Michele Mario Ciulla\* , Gianluca Lorenzo Perrucci and Fabio Magrini

\*Address all correspondence to: michele.ciulla@unimi.it

Department of Clinical Science and Community Health, Laboratory of Clinical Informatics and Cardiovascular Imaging, University of Milan, Milan, Italy
