Darwin's anatomical discoveries
Vestigial Features
Did you know there are some species of fish that have eye sockets with no eyes?
There are some running animals that have an extra toe that never touches the
ground. Some types of beetles have wings but they can not fly. These features
are what Darwin termed vestigial.
Vestigial Features : Rudimentary and non-functioning structures that are
homologous to fully functioning structures in closely related species.
There are some running animals that have an extra toe that never touches the
ground. Some types of beetles have wings but they can not fly. These features
are what Darwin termed vestigial.
Vestigial Features : Rudimentary and non-functioning structures that are
homologous to fully functioning structures in closely related species.
Some species of cave fish for example, live in such darkness that seeing serves
no purpose. These are the species of fish that have
visible eye sockets but
have no developed eyes. The upland goose and frigate bird both have feet that
are webbed but neither of these animals are water animals.
no purpose. These are the species of fish that have
visible eye sockets but
have no developed eyes. The upland goose and frigate bird both have feet that
are webbed but neither of these animals are water animals.
Darwin explains these features as evolutionary changes. An ancestor of these species once needed these features but throughout time the new species no longer needed the feature so they did not fully develop it. Another good example that involves humans is goosebumps. Humans get goosebumps when we feel a chill or are scared. Small bumps form on our skin and our body hair will stand up. Similarly, when an animal such as a cat is cold their hair will stand up in order to help with insulation. When a cat is scared, their hair will also stand up which is a
threat mechanism that makes the animal look larger and mennacing to scare of predators. As humans, we know that the mechanism of our thin hairs do not help to keep us any warmer nor would it help to scare away any predators if we were in danger. Therefore, this feature in humans is vestigial although it is commonly used by common our common ancestors.
threat mechanism that makes the animal look larger and mennacing to scare of predators. As humans, we know that the mechanism of our thin hairs do not help to keep us any warmer nor would it help to scare away any predators if we were in danger. Therefore, this feature in humans is vestigial although it is commonly used by common our common ancestors.
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