AP BIOLOGY

Detailed explanation-1: -Common descent is a concept in evolutionary biology applicable when one species is the ancestor of two or more species later in time.

Detailed explanation-2: -Mitochondrial Eve and the most recent common patrilineal ancestor of all living male humans, known as Y-chromosomal Adam, have been established by researchers using tests of the same kinds of DNA as for two individuals. Mitochondrial Eve is estimated to have lived about 200, 000 years ago.

Detailed explanation-3: -All animals (including humans), plants and other organisms such as fungi and algae are Eukaryotes and share a common ancestor. And universal common ancestry would have it that all three domains themselves stem from a single root.

Detailed explanation-4: -All known life forms trace back to a last universal common ancestor (LUCA) that witnessed the onset of Darwinian evolution. One can ask questions about LUCA in various ways, the most common way being to look for traits that are common to all cells, like ribosomes or the genetic code.

Detailed explanation-5: -Hippos and whales may look different in many ways, but they are actually each others’ closest living relatives-sharing a common ancestor that lived about 55 million years ago.