The difference between vestigial and atavistic traits lies in the fact, at which the ancestors of a given individual – immediate or remote, there is a particular symptom, or whether it is the norm or a deviation.
Atavism is a trait that was present in the evolutionary ancestors of this species, but to existing ones it does not mean inherent. However, genes encoding it, can be preserved, passed down from generation to generation. Under certain circumstances, these "dormant genes" can "Wake up", and then individual is born with an atavistic trait.
For example, the Tarpan – an extinct wild ancestor of horses, on the feet, there were marks in the form of strips. In modern horses, they are not, but occasionally individuals are born with similar markings. In the early 19th century, the birth of such foal from the horse that for 2 years before that unsuccessfully mated with a male Zebra, was the impetus for the emergence of pseudo-scientific theories of telegony.
Meet atavistic traits in humans. Sometimes people are born with a solid hairline like a monkey, with extra mammary glands like other mammals, with an appendage in the form of the tail. Until the mid-20th century these people were one way – in a booth or in a circus to amuse the audience with his unusual appearance.
A vestigial characteristic is the same legacy of evolutionary ancestors. But if the throwback is the exception, a vestige of the rule.
Vestigial organs in the course of evolution has degenerated and lost its function, but they are present in all members of this type, therefore, the birth of individuals with such a sign is not a deviation from the norm.
An example of a vestigial organ – the eyes of a mole: very small, almost not seeing. However, normal moles are born with eyes, the birth of a mole without eyes is possible only as a result of genetic abnormalities or birth defects.
An example of a vestigial organ in humans – the muscles surrounding the ear. Other mammals they help to wiggle his ears, listening, but few people are capable of it. A vestige is a coccyx – a tail degraded.
With the vestiges do not confuse homologous organs that in utero arise, but to fully develop and function in individuals of only one gender – for example, immature mammary glands in men. Do not mix with the rudiments and provisional bodies that exist only in embryos and disappearing afterwards.
Atavism
Atavism is a trait that was present in the evolutionary ancestors of this species, but to existing ones it does not mean inherent. However, genes encoding it, can be preserved, passed down from generation to generation. Under certain circumstances, these "dormant genes" can "Wake up", and then individual is born with an atavistic trait.
For example, the Tarpan – an extinct wild ancestor of horses, on the feet, there were marks in the form of strips. In modern horses, they are not, but occasionally individuals are born with similar markings. In the early 19th century, the birth of such foal from the horse that for 2 years before that unsuccessfully mated with a male Zebra, was the impetus for the emergence of pseudo-scientific theories of telegony.
Meet atavistic traits in humans. Sometimes people are born with a solid hairline like a monkey, with extra mammary glands like other mammals, with an appendage in the form of the tail. Until the mid-20th century these people were one way – in a booth or in a circus to amuse the audience with his unusual appearance.
Vestige
A vestigial characteristic is the same legacy of evolutionary ancestors. But if the throwback is the exception, a vestige of the rule.
Vestigial organs in the course of evolution has degenerated and lost its function, but they are present in all members of this type, therefore, the birth of individuals with such a sign is not a deviation from the norm.
An example of a vestigial organ – the eyes of a mole: very small, almost not seeing. However, normal moles are born with eyes, the birth of a mole without eyes is possible only as a result of genetic abnormalities or birth defects.
An example of a vestigial organ in humans – the muscles surrounding the ear. Other mammals they help to wiggle his ears, listening, but few people are capable of it. A vestige is a coccyx – a tail degraded.
With the vestiges do not confuse homologous organs that in utero arise, but to fully develop and function in individuals of only one gender – for example, immature mammary glands in men. Do not mix with the rudiments and provisional bodies that exist only in embryos and disappearing afterwards.