When two groups of organisms independently evolve similar adaptations, it’s called convergent evolution. Sharks and whales both have streamlined bodies and tail flukes. How do we know that these similarities are because of convergent evolution? Hint: Whales are tetrapods. Are sharks?

answer; (a) medicalized;

when charles darwin published  the origin of species  150  years ago he consciously avoided discussing the origin of life. however, analysis of some other texts written by darwin, and of the correspondence he exchanged with friends and colleagues demonstrates that he took for granted the possibility of a natural emergence of the first life forms. as shown by notes from the pages he excised from his private notebooks, as early as 1837 darwin was convinced that “the intimate relation of life with laws of chemical combination, & the universality of latter render spontaneous generation not improbable”. like many of his contemporaries, darwin rejected the idea that putrefaction of preexisting organic compounds could lead to the appearance of organisms. although he favored the possibility that life could appear by natural processes from simple inorganic compounds, his reluctance to discuss the issue resulted from his recognition that at the time it was possible to undertake the experimental study of the emergence of life.