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7 Evolutionary Leftovers in Your Body

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7 Evolutionary Leftovers in Your Body

By Brie Cadman, DivineCaroline

Wings on a flightless bird, eyes on a blind fish, and sexual organs on a flower that reproduces asexually—the casual observer might ask, what’s the point? But these vestigial organs and structures, once useful in an ancestor and now diminished in size, complexity, and/or utility, carry important information and give us clues to our evolutionary past.

Though humans often think of vestigial organs as useless little fixtures that sometimes, as in the case of the appendix, cause us extreme anguish, we wouldn’t know nearly as much about macroevolution as we do now without their presence. In On the Origin of Species, Charles Darwin used vestigial organs as evidence for evolution, and their presence has helped define and shape our phylogenetic trees.

Why the Leftovers?
Contrary to what most think, vestigial doesn’t necessarily mean useless; in some cases, we may just not yet know exactly how the organ is used in its current incarnation. (The human thymus was once thought to be vestigial). Because these structures can be traced back through the ancestors, they essentially serve as a marker of evolution; no organism can have a vestigial organ that hasn’t been found in its forefathers. For this reason, you won’t ever find feathers on a mammal or gills on a primate.

Similar in concept to vestigial structures are atavisms, which are the reappearance of a structure or trait that isn’t found in the immediate ancestors. For instance, whales and dolphins have been found in nature with hind limbs; this rare occurrence is due to the reemergence of a trait they inherited from their terrestrial ancestors.

Humans also contain structures that mark where we came from and perhaps, which structures’ evolution will take care of over time.

Wisdom Teeth
Our ancestors, known to be herbivores, needed strong molars for mashing up and chewing plant material. This relic is why many of us will develop wisdom teeth, also known as third molars. Theoretically, they could still be used for chewing, but in one third of people, they can come in sideways, impacted, or can cause pain and infection. This is why these vestigial structures are almost always removed when they begin to come in.

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DivineCaroline

At DivineCaroline.com, women come together to learn from experts in the fields, of health, sustainability, and culture; to reflect on shared experiences; and to express themselves by writing and publishing stories about anything that matters to them. Here, real women publish like real pros. Together, with our staff writers, they’re discussing all facets of women’s lives from relationships and careers, to travel and healthy living. So come discover, read, learn, laugh and connect at DivineCaroline.com.

117 comments

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12:01PM PDT on Aug 1, 2011

For those of us who question evolution, here is a thought.
What if so called vesti-orgs are actually insurance against the future? Might be things we will need later on as the Earth develops and changes.
We adopt thoughts such as evolution with no real evidence. No one has yet documented a new species. Hybrids occur and could easily be mistaken for a 'new' species. Explain the platypus! Dinos became birds?
For instance, plants contain all of our mammal chemicals. Limbs may have design patterns mimicking tree limbs. How does a plant replicate pheromones of insects? Even they're flight patterns. I see something else at play here.
Evolution was embraced by superior race aficionados.
There are many questionable things relating to the old Beagle Boy.
It is said that science has only a few real facts. Has anyone ever seen a list?

11:55AM PDT on Aug 1, 2011

Wow interesting!

6:30PM PDT on Jul 16, 2011

Very interesting.

6:59PM PDT on Jul 1, 2011

Interesting

5:02PM PDT on May 31, 2011

Most sorry about our loss of a tail!

10:58AM PDT on May 7, 2011

Very interesting- thanks!

10:37AM PDT on May 7, 2011

Nipples on a male have the same sexual feeling as females.

6:55AM PDT on May 5, 2011

I wish I could wag my tailbone...

6:54AM PDT on May 5, 2011

Oops, yes! When my cousin was small, a milkman used to come to that area and leave bottles of milk on the doorstep. Thus, when Robert was asked who gave milk (the target answer was: a cow), he'd say: 'the man'.

6:53AM PDT on May 5, 2011

Oh, if men could give milk...

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Disclaimer: The views expressed above are solely those of the author and may not reflect those of
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