Has a new functional structure ever been observed arising spontaneously?

Question

Have we ever observed a new functional biological structure arising spontaneously such as a new functional organ (sensory or otherwise. such as tracing some creature in the past few hundred years which had no electroreception organ and now has evolved this organ)

Or has what we observed been limited to changes in existing structures.

(Lenski's E. coli bacteria is not what i am looking for since it is a change in an existing metabolic system (not a new functional structure) and furthermore e-coli already had some ability to use citrate as an energy source )

Looking for a completely new functional organ (such as a new sensory organ) that we have actually observed - not deduced from fossil record.

Also not looking for something trivial such as a new/modified enzyme or protein molecule but rather a new organ in a species at least the size of an insect.

Answer 1

It seems like you are attempting to frame this as a question about current evolutionary theory. However, current evolutionary theory doesn't expect anything as complex as an organ to arise spontaneously without any precursors. You suggest a new claw in an insect would be something "spontaneous" enough for you. This again shows that your question and the answer you are looking for are not related to evolutionary theory. The insect organs you are talking about are all modified appendages. This includes claws, mandibles, antennae, legs, fangs. These appendages all share a common genetic and developmental framework that has been slightly modified over long periods of time to give raise to the variety of insect appendages that we see today.

The idea that evolutionary theory supports the spontaneous creation of organs is a willful ignorance of evolutionary theory. The molecular mechanisms that generate novelty (e.g. genome duplication, gene duplication, de novo genes, mutation, gene regulation) for natural selection to work on are relatively well understood. Since we have an understanding of how novelty is created it is known that spontaneous organ generation has never happened or is expected to happen under evolutionary theory.

Here is link to the University of California, Berkeley's webpage designed to teach the public about evolution.

Answer 2

How about the Italian wall lizards that evolved new muscles around their intestines after being introduced to an island? (other article, actual paper). The paper reports that these cecal valves are "a structure previously unreported for this species and rare in this family and scleroglossan lizards in general"; indeed, "The fact that <1% of all currently known species of squamates have cecal valves ... illustrates the unusual nature of these structures in this population.".

It is possible that these values are an ancestral structure that was reactivated by natural selection; however, we know that natural selection can act very quickly to change the size of morphological structures, so it's also possible that existing muscles quickly changed size in response to selective pressure. Figuring out the developmental mechanism of cecal valves would sort that out.

Answer 3

To be sure a new trait actually evolved before our very eyes and wasn't simply mistaken for a wild trait we never noticed, you probably want to look at domestic animals. We have directly observed, through animal husbandry, the evolution of new fingers in cats, new ribs in pigs (wild pigs have 14, some breeds now have 17), new fins in fish (here I'm talking about the double tail mutation in golfish).

These new structures act, for the most part, like the old ones. I assume because of this you might be interested too, in the observed evolution of completely new functions from old parts:

The Norwegian Lundehund (dog breed) has evolved the ability to seal its ears shut with muscles that other dogs/wolves use to simply move their ears.

As someone else mentioned, In an island population of Podarcis sicula (lizard species), muscles in the digestive tract which normally function to squeeze food through the intestines, have bunched up to form a new valve, thus creating a fermentation chamber.

Off the top of my head, I can't think of other directly observed changes in function but there are MANY super solid inferred changes in function:

Bee stingers are modified ovipositors (egg-laying organ). We know this because they are nearly identical to the ovipositors of other insects, and because the queen uses hers as a stinger and as an ovipostor.

Snake venom is modified saliva and snake fangs are simply a merger of tooth and saliva duct.

Bird wings are modified arms with 3 fingered claws. I could go on but I'll call that good.

Answer 4

There are two main issues in your question that make it hard or fundamentally impossible to answer. The two issues are

• What you would accept being an 'observation'
• What you would accept being significant enough to be an example of interest.

A big issue in your question is based upon what you call an observation!

When you say

observed - not deduced

, you highlight the whole issue of what you would consider being an observation.

In science, observations often take complex form. It is not only direct visual observation recorded on a standard camera. It is like asking for, recorded-on-camera evidence that quartz exist. Such evidence don't exist (and cannot exist), yet we know of their existence through other means of observation. It would make no sense for someone to only consider camera recording as valid mean of observation.

Of course, We have never recorded on a camera the evolution of an entire new organ because it takes a lot of time. Yet, evidences are numerous.

This technic of limiting arbitrarily the field of methods that one accepts to recognize as bringing evidence and call "observation" is a common technic from science denier (e.g. flat earth society, creationist). I made a similar point as the one I made here on this post if you want.

How to solve this "What is an observation" problem?

There is only one way to go. It will be for you to be able to understand the forms that observation can take. For this, you will have to learn a little bit about evolutionary biology and evolutionary genetics. For a very short introduction to evolutionary biology, you can have a look at Evo101 by UC Berkeley.

You may have hoped for someone to give an entire course on evolutionary biology to fill up this gap of knowledge of yours but I am afraid it would be way too much work for a single post. If this was your position, then it would be like refusing to accept that earth is a sphere without having yourself explain how GPS data work. We just can't give you an entire course here.

So you have two solutions; rely on authority or understand by yourself. If you rely on authority you have two main options; Rely on those that rely on evidence (science) or those that don't rely on evidence and either rely on other forms of justification (justification theory;such as a religious book for example). (either those that work through observations, scientists). You second solution is to understand the field by yourself and therefore start studying for it.

A second issue is that it is unclear to know what you would accept being "not trivial"

When you say

Also not looking for something trivial such as a new/modified enzyme or protein molecule but rather a new organ in a species at least the size of an insect

It is hard to know what you would call a significant enough evolutionary event to be accepted. The risk is that you may define it large enough so that it fundamentally cannot be observed by a mean that you would accept.

For your curiosity, this post talks about evolution of lactose digestion in humans and this post about the evolution of cardio-vascular system.

Somewhat related post

You might want to have a look at post Is evolution a fact? and the link posts in the top voted answer.

Just another comment

random evolution

In the scientific literature, "evolution" is never said to be "random". The fact that you're using this expression shows what kind of literature you are used to.

For all reasons explained above, the question cannot be answered, not by lack of evidence, but because the question is unclear. I am therefore voting to close as unclear. Good luck in your investigation of the question.