AP BIOLOGY

Detailed explanation-1: -In divergent evolution, two or more distinct species share a common ancestor from which they diverged. A common example is a modern elephant and woolly mammoth. They share a common ancestor and yet evolved into two different species. Another example is the dog, the wolf, and the fox.

Detailed explanation-2: -The first eukaryotic cells-cells with a nucleus an internal membrane-bound organelles-probably evolved about 2 billion years ago. This is explained by the endosymbiotic theory. As shown in the Figure below, endosymbiosis came about when large cells engulfed small cells.

Detailed explanation-3: -One important moment in evolution was the origin of mitochondria, a component of eukaryotic cells that function as their ‘power plants’. Mitochondria were once free-living bacteria, but during evolution, they were absorbed by the ancestors of today’s eukaryotic cells.

Detailed explanation-4: -Eukaryotes were found to evolve faster than prokaryotes, with those eukaryotes derived from eubacteria evolving faster than those derived from archaebacteria. We found an early time of divergence ( 4 billion years ago, Ga) for archaebacteria and the archaebacterial genes in eukaryotes.