Similar testable hypothesis:
For instance, if two buildings appear closely related it is more likely that they have similar elevator configurations than two dissimilar buildings.
ML/NJ
For instance, if two buildings appear closely related it is more likely that they have similar elevator configurations than two dissimilar buildings.
It's not just "similar elevator configurations". It's tiny, random mutations (that have no effect on the organism or any of its biochemical functions) that are more likely to be shared by closely related species. Indeed, if you look at endogenous retroviruses, the case for descent with modification from common ancestors becomes inescapable. Here's the story: Retroviruses such as HIV have the property that they splice their own genetic information into the DNA of a cell they infect. Occasionally, a retrovirus will manage to infect an egg cell: that individual when the egg is fertilized and develops into an adult will have that retrovirus DNA in its genome and so will its decendents. Retroviruses aren't choosy about where their DNA gets spliced in; it's a random process. Often the new DNA doesn't really affect anything, so it doesn't get selected out of the gene pool very quickly. It turns out closely-related organisms will share many of these old retroviral DNA segments, in the same random locations. This has been documented for various species, establishing beyond doubt their common ancestry (just as DNA testing is used to establish paternity in humans).