1.7The Development of Life Science
Life science began as a discipline that was applicable to only humans, but evolved considerably and ultimately became a discipline applicable to all living organisms on the earth. Today, life science research includes not only fundamental research about genomes, evolution, and the like, but also research about humans regarding medical issues, food, health, and the entire mind and body. Life science also deals largely with environmental problems of the earth on which we live and about our coexistence with other living organisms. We also cannot avoid ethical problems such as those involving cloning and genetic testing (Fig. 1-6).
Moreover, now that the genomes of many living organisms have been sequenced in the 21st century, we are able to solve problems using the same methodologies regardless of what organism we are studying.
However, research on the functions of cells at the molecular level, the behavior of individual organisms, the processes of ecosystems, and the evolution of organisms depends more than ever on knowledge of not only conventional biology, but also fields such as physical chemistry, biochemistry, molecular biology, earth science, and psychology. Furthermore, such research requires a synthesis of these fields at various spatial and temporal levels. Without a doubt, balanced opinions are acquired not only through study of individual academic disciplines, but also through investigation of synthesis of various disciplines (E.O. Wilson).
Hypotheses and Truth
"Humans did not exist during the Jurassic period of the Mesozoic era when dinosaurs roamed the earth." Can such a hypothesis be formed? Certainly, all human bones that have been excavated from geological strata have been from the Quaternary period of the Cenozoic era and not from the Mesozoic era. This hypothesis seems correct from the perspective of evolution as well because measurements using radioactive isotopes has shown that humans appeared no more than several million years ago. However, it has actually not been proved in the strict sense that humans did not exist during the Jurassic period. If dinosaur and human bones were ever discovered together in a geological stratum from the Jurassic period, it would be time to revise the current evolutionary theory, and the possibility of such a discovery exists. That said, we do not take the position that evolutionary theory is incorrect just because such a possibility exists. The course of evolution (morphology and DNA) of all organisms suggests that humans and monkeys diverged from common ancestors 6 million years ago, and this conclusion is as good as truth. "Humans did not exist during the Jurassic period" is not a hypothesis to be tested.
Furthermore, evolutionary theory is sometimes rejected, and ingenious speculations about the birth and evolution of life are sometimes invented because religious beliefs are valued over the knowledge of natural science. However, these speculations do not refute the claims of life science. The history of our life is not so simple that it can be replaced by imagination.