Did you know about Vestigial Structures Humans and Animals? Are they really supporting theory of Evolution?

Vestigial Structures /Organs

      Vestigial structures humans and animals are historical remnants of structures that were once performing important functions in ancestors but now they are no longer fully functional.
They supports theory of evolution ''Descent with Modification''and ''Divergent Evolution'' which states:

"When ancestrol organisms inhabit different habitat their particular structures modify according to needs of survival in habitat. So their function changes."

 Examples;
       1- Skeletal elements modifies to form different forelimbs in mammals   i.e., Birds and bats fly,  Human walks, Fishes and Whales swim .

2-Flowers are modified to form leaves, petals, sepals, stamens and carpels.

Vestigial Structures Humans

1-Coccyx

It is also known as Tailbone. It is a small, triangular bone at bottom of spine  that resemble shortened tail.It forms tail in other tailed animals but this vestigial structures is useless in human.

2-Ear Muscles

In ancestors ear muscles help them pivot their ears to and fro but now humans are not capable of moving them much.

3-Nictating Membrane of Eye

Its pink semilunar fluid in inner corner of eye. This vestigial structures humans is remnant of third eye lid that is said to move horizontally on Eyeball. It is still fully functional in some mammals.

4-Vermiform Appendix

  It is muscular structure attatched to intestineresembles worms. In past this vestigial structures humans helps herbivorous ancestors to digest cellulose. Now it helps in simple digestive and mucosal immune system. It is present in all carnivores.

5-Wisdom Teeth

Due to reduction in jaws with evolution ,size of molars is reduced especially third molars (wisdom teeth) become congenitally absent.

The people who get their wisdom teeth developed find that they do not have enough space in their oral cavity to accommodate a third molar. So now a days, wisdom teeth have become largely considered as vestigial structure that is unnecessary like coccyx and ear muscles etc.

 They can also lead to few oral health complications or diseases like overcrowding and an increased risk of infection . Because they try to erupt out from the gumline.

That’s why dentists often recommend that the wisdom teeth  should be extracted during the adolescence or early adulthood if they errupt out from gumline. It is possible that future generations donot develop wisdom teeth at all.

5-BODY HAIRS

Vestigial Structures in Animals

1-Vestigial Structures in Snakes

About 150 million year ago snake were tetrapods and use to walk on earth. Scientist purpose two way evolution (burmese python and dna sequence) and now they are embedded in muscles.

Snakes are believed to have descended from lizards. Their legs grew smaller and smaller until a small bump was left at the back of some of the largest snakes like pythons.

2-Vestigial Structures in Blind Fishes and Salamanders

Salamanders and blind fishes still have eye structures but are blind and live in caves. Scientists believes that mutations in genes that increased their taste buds have actually degraded their eyes, making them blind.

But blindness in cave salamanders is not an unfavourable trait for them. Eyes are  vulnerable to infectious agents and provide a path straight to the brain. If the vision or eyes are not beneficial within their environment, it is better not have them.

3-Vestigial Structures in Cockroaches

Cockroaches have wings. The wings that are present on the females do not facilitate flying.Most species of cockroach have wings, but having wings is not the same thing as having wings that work. 

Some cockroaches, like the Central American giant cockroach, are so huge, and spend most of the time underground so they donot need wings. Other species that  have wings are only vestigial or non-functioning wings.

4-Vestigial Structures in Whale Shark

The whale shark is a filter feeder. It consists of rows of teeth that cannot bite anything.Their teeth don’t play a major role in feeding. In one of their filter-feeding methods, they suck water into their mouths at high velocities while remaining stationary.

Their throats are covered with filtering pads and food is passes through it. These filtering pads are broad full of millimeter-wide pores that act like a sieve, which allows the water to pass through while capturing food particles.

5-Vestigial Structures in Galapagos 

The Galapagos cormorants have wings which are non-functional. These birds are believed to have turned into flightless birds abut 2 million years ago.

MOLECULAR BIOLOGY PROVES DIVERGENT EVOLUTION.