In trees, what is the old, dead pholem called?

According to the theory of punctuated equilibrium, at what rate does speciation occur? species change depending on the rate of natural selection. after periods of stasis, new species evolve relatively rapidly. species change slowly and eventually form new species. some species change quickly and others change slowly to balance the overall rate.

Which description provides the best objective summary of the article in the passage?

What class of levers is shown in this image?