On what type of land does primary succession first begin to occur

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.

answer; ///stratum basale///stratum spinosumstratum granulosumstratum lucidumstratum corneum; 2,1,5,4,3