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:
“Science is intimately integrated with the whole social structure and cultural tradition. They mutually support one other—only in certain types of society can science flourish, and conversely without a continuous and healthy development and application of science such a society cannot function properly.”
—Talcott Parsons (1902–1979)
“If there is nothing new on the earth, still the traveler always has a resource in the skies. They are constantly turning a new page to view. The wind sets the types on this blue ground, and the inquiring may always read a new truth there.”
—Henry David Thoreau (1817–1862)
“Rules and particular inferences alike are justified by being brought into agreement with each other. A rule is amended if it yields an inference we are unwilling to accept; an inference is rejected if it violates a rule we are unwilling to amend. The process of justification is the delicate one of making mutual adjustments between rules and accepted inferences; and in the agreement achieved lies the only justification needed for either.”
—Nelson Goodman (b. 1906)