The earliest stage in the chart appears very similar for all three species. For example, all three embryos at this stage have gill slits and a large embryonic tail. What do these similarities most likely indicate?

one would be wind another would be water density

the water is warmed up by the sun and then it evaporates into the atmosphere. the sunlight warms the water by its heat. water is then cooled down and condensation takes place. the water then finally returns back to the earth by the process of precipitation in the form of rain or ice.

explanation: