Similarly, while the sinus venosus is present as a vestigial structure in some reptiles and birds, it is otherwise absorbed into the right atrium and is no longer distinguishable.
12.
Erasmus Darwin noted that some species have vestigial structures which are anatomical structures that have no apparent function in the species currently but would have been useful for the species'ancestors.
13.
"' Vestigial structures "'are often called " vestigial organs ", although many of them are not actually variable than homologous non-vestigial parts.
14.
Some large primates such as gorillas and orang-utans ( and also humans ) have undeveloped ear muscles that are non-functional vestigial structures, yet are still large enough to be easily identified.
15.
In the context of human evolution, "'human vestigiality "'involves those vestigial " often appear functionless, a vestigial structure may retain lesser functions or develop minor new ones.
16.
They are most often found deep to the anterior aspect of the ear drum, and a vestigial structure, the epidermoid formation, from which congenital cholesteatoma may originate, has been identified in this area.
17.
However, some vestigial structures may persist due to limitations in development, such that complete loss of the structure could not occur without major alterations of the organism's developmental pattern, and such alterations would likely produce numerous negative side-effects.
18.
The zoologist Horatio Newman said in a written statement read into evidence in the Scopes Trial that " There are, according to Wiedersheim, no less than 180 vestigial structures in the human body, sufficient to make of a man a veritable walking museum of antiquities ."
19.
This is why the zoologist Horatio Newman said in a written statement read into evidence in the Scopes Trial that " There are, according to Wiedersheim, no less than 180 vestigial structures in the human body, sufficient to make of a man a veritable walking museum of antiquities ."
20.
The fact that evolved traits tend to persist even if a change in ecological conditions renders them less adaptive or altogether useless, is a good part of why many organisms have vestigial structures and why regressive traits tend to be fairly rare and often viewed as confounding when they do occur ( for example, in the famous talk 16 : 12, 7 May 2014 ( UTC)
