What Are Some Structures In Plants And Animals That Serve A Similar Purpose

Definition

Coordinating structures are similar structures that evolved independently in 2 living organisms to serve the same purpose.

The term "analogous structures" comes from the root give-and-take "analogy," which is a device in the English language where ii different things on a basis of their similarities.

Analogous structures are examples of convergent development, where ii organisms separately have to solve the same evolutionary problem – such as staying hidden, flying, swimming, or conserving h2o – in like ways. The upshot is similar torso structures that developed independently.

In the case of analogous structures, the structures are non the same, and were not inherited from the same ancestor. Merely they look similar and serve a similar purpose.

For example, the wings of an insect, bird, and bat would all be coordinating structures: they all evolved to permit flying, but they did non evolve at the same fourth dimension, since insects, birds, and mammals all evolved the ability to fly at different times.

Examples of Analogous Structures

Wings Through The Ages

As mentioned higher up, many creatures take independently adult wings. All wings were evolved in order to solve the same problem: how to fly through the air. But they have evolved on several different occasions throughout history.

Insects were the first organisms to evolve structures which could push air down in order to propel their bodies through the air. Insects probably evolved flight by using parts of their protective exoskeletons to propel themselves through the air.

Millions of years later, reptiles learned to do the same thing- pterosaurs evolved a skin membrane, stretched betwixt their finger and ankle bones, which was capable of propelling them through the air.

Millions of years later on nevertheless, dinosaurs separately evolved flight – using the feathers they had developed to keep warm in social club to push them into the heaven. In the process, these small, feathered dinosaurs evolved into birds.

Mammals solved the problem of flight yet once more about 100 million years after birds first appeared, with bats using a similar solution to that of the pterosaurs: skin membranes stretched between long finger bones.

In this manner, nosotros have at least 4 different types of wings in the fossil record which are analogous: they serve the aforementioned purpose, just were not inherited from the same ancestor.

The "Duck-Billed" Platypus

When the first specimen of a platypus was sent to a British museum past an Australian explorer, they tried to pry it apart to testify it was a faux! British scientists were certain that someone had simply stuck a duck's neb onto the trunk of a beaver-like fauna.

However, the truth was much more interesting: platypi had evolved virtually exactly the same structure evolved by ducks to solve the problem of gathering food such every bit fish and aquatic plants from water.

Ducks and platypi could not possibly exist related – platypi are mammals, and they evolved long after birds and mammals went their split up means on the evolutionary path. Yet both evolved very similar solutions when they moved from land back into the water!

Cacti and Water Conservation

Some members of the plant genres Euphorbia and Astrophytum look extremely similar.

Both take round, ball-shaped bodies divided into eight equal wedges; both have hard, pointy thorns sticking out in a row along the eye of each wedge, protecting them from animals who might try to eat them. To the untrained eye, they may be mistaken for members of the aforementioned species.

This is particularly remarkable because these two genii are only distantly related, and they live in two completely different parts of the earth.

Astrophytum evolved in North America, and all members of its genus are cacti that alive in the southwestern deserts.

Euphorbia, on the other hand, is a plant genus that includes poinsettias – as well equally sure cacti found in the deserts of Africa.

Both the African and North American cacti conserve h2o by minimizing their area – resulting in a round, ball shape – developing a thick, waxy skin, and placing prickly deterrents on its skin at its most vulnerable places to discourage animals from trying to swallow it for its wet.

The result is two plants which look nearly identical – but which have very dissimilar ancestry!

Difference Betwixt Analogous and Homologous Structures

The divergence between homologous and analogous structures can exist thought of in terms of ancestry and office:

• Analogous structures have different ancestry, merely the same role.

These can exist idea of in terms of the literary device of "analogy," where 2 different things are compared based on their similarities.

• Homologous structures have the same beginnings, but may no longer serve the same function.

For example, the basic that make up homo fingers were inherited from an ancestor that'south shared by all mammals. Bats, dogs, and whales also take these bones, only bats use them to spread their wings, dogs walk on them, and whales practise non utilize them for annihilation since they are encased within their fins.

These structures are therefore homologous – there is a clear relationship and similarities betwixt them, even though they are not used for the same purpose.

The existence of homologous structures is strong evidence for the theory of development, since at that place is no reason why a whale should have the aforementioned bones in its fin that a bat has in its wings, unless they both evolved from a common ancestor.

These tin be idea of in terms of the literary device of "homonyms," where 2 words sound the aforementioned, but have different meanings.

Identifying Analogous Structures

Scientists unremarkably identify analogous structures past looking at the known relatives of the two species being studied.

If a line of common inheritance can exist found – such as humans and monkeys both having fingers, when nosotros accept a fossil record showing that humans and monkeys shared a common antecedent, who besides had fingers – the structures are not considered analogous.

Just if no common ancestor which shares these features is found – such as in the instance of bats and insects, whose shared ancestor did not fly at all – the structures would be considered coordinating.

• Convergent evolution – When two species independently evolve similar solutions to an evolutionary problem.
• Evolution – The process past which organisms change over time, due to natural selection and survival of the fittest.

Quiz

1. Which of the following is Non an case of convergent development?
A. Cacti in North America and Africa that have the same body structures.
B. Birds and bats that are both able to wing.
C. Whales and bats that both have metacarpal "finger" basic.
D. Platypi and ducks that both take duck bills.

Answer to Question #1

C is right. Whales and bats did not evolve metacarpals to serve the same purpose – they inherited them from a mutual ancestor.

ii. Which of the following is true of coordinating structures?
A. They take the same function, and the aforementioned beginnings.
B. They have the same part, simply unlike beginnings.
C. They take the same ancestry, but may have different functions.
D. They accept unlike ancestry, and different functions.

Answer to Question #ii

B is correct. Analogous structures are structures which perform the same function, but have different beginnings.

3. Nosotros know that organisms must have evolved structures independently if they do not take a common ancestor.
A. True
B. False

Respond to Question #three

Truthful & False. This is a play tricks question. Information technology is true that organisms must have evolved structures independently if they don't take a common ancestor who has the structure in question.

Birds and bats could not have inherited wings from a shared ancestor, for example, because the earliest mammals from whom bats descended did non have wings.

Yet, all organisms living on Earth have a mutual ancestor somewhere in their past. It'southward merely a question of whether that common ancestor is the source for their shared trait, or whether it evolved in both species independently after their family trees diverged.

Source: https://biologydictionary.net/analogous-structures/

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