Phylogenetic Bracketing - Types of Inference

Types of Inference

There are three types of inferences that can be drawn based on phyolgeny. The above example, concluding that Tyrannosaurus could lay amniotic eggs, is the standard type, and is called a type I inference. A type II inference is made where one of the extant relatives has the trait and the other does not. In the case of the Tyrannosaurus, a type II inference could be to conclude that it had feathers (like a bird). This is less certain, and depends on at what stage feathers evolved. From phylogeny alone, it is equally possible Tyrannosaurus had scutes (like a crocodile). In contrast, concluding that Tyrannosaurus had hair would be a type III inference, and considered unlikely. Type III inferences are only warranted if there is some positive evidence that the extinct creature possessed the trait.

Read more about this topic:  Phylogenetic Bracketing

Famous quotes containing the words types of, types and/or inference:

    Our children evaluate themselves based on the opinions we have of them. When we use harsh words, biting comments, and a sarcastic tone of voice, we plant the seeds of self-doubt in their developing minds.... Children who receive a steady diet of these types of messages end up feeling powerless, inadequate, and unimportant. They start to believe that they are bad, and that they can never do enough.
    Stephanie Martson (20th century)

    Our major universities are now stuck with an army of pedestrian, toadying careerists, Fifties types who wave around Sixties banners to conceal their record of ruthless, beaverlike tunneling to the top.
    Camille Paglia (b. 1947)

    I shouldn’t want you to be surprised, or to draw any particular inference from my making speeches, or not making speeches, out there. I don’t recall any candidate for President that ever injured himself very much by not talking.
    Calvin Coolidge (1872–1933)