Why do dolphins have olfactory receptor (OR) genes?

pitabread said:

Dolphins have both fully formed and various broken bits of olfactory receptor genes in their genomes. Yet, they completely lack an olfactory system and associated organs (i.e. they can't smell).

From an evolutionary point-of-view, it makes sense given that they descended from land mammals and their olfactory gene remnants are simply a part of that heritage.

From a special creation point-of-view, it makes no sense whatsoever. Unless the creator is a sloppy coder, cutting and pasting bits of genomes together and not cleaning up after themselves.

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Why do you have an appendix? Years ago, ppl asked this question, and there were lots of appendix operations and often the reason was given, was: Oh, whatever it's for, it doesn't matter, it must just be some left-over from some evolutionary phase.

However, this is not the current medical thinking; there now is reluctance to remove the appendix unless it's really necessary.

My point is, it's easy to dismiss things that we don't necessarily fully understand now.

faroukfarouk said:

My point is, it's easy to dismiss things that we don't necessarily fully understand now.

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You are correct. However the question is "From where did this genome structure derive?"

The blindingly obvious conclusion is that dolphins or their evolutionary forebears had smelling noses at one time. Why, I haven't a clue. That's one of the things I will ask God, provided humanity doesn't figure it out prior to my demise.

pitabread said:

Dolphins have both fully formed and various broken bits of olfactory receptor genes in their genomes. Yet, they completely lack an olfactory system and associated organs (i.e. they can't smell).

From an evolutionary point-of-view, it makes sense given that they descended from land mammals and their olfactory gene remnants are simply a part of that heritage.

From a special creation point-of-view, it makes no sense whatsoever. Unless the creator is a sloppy coder, cutting and pasting bits of genomes together and not cleaning up after themselves.

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Evolution can work it's magic very quickly. Having the code to do so allows for
species to be ready to go when changes are best. Climate change for example.

Rapid Evolution Changes Species in Real Time

Fast evolution affects everyone, everywhere

Earthquake Forced Rapid Evolution in Fish

pitabread said:

From a special creation point-of-view, it makes no sense whatsoever. Unless the creator is a sloppy coder, cutting and pasting bits of genomes together and not cleaning up after themselves.

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You know what I found!?

I found that the same material the cover of my Bible is made of, also covers cows!

It seems to me that someone is using cow hides to make Bible covers!

Same genomes, same DNA, same everything.

Either someone is very frugal, or someone is operating on a limited budget!

All seriousness aside though: I think the term you're looking for is ontological reduction.

Wendy's said it best: "Parts is parts."

Pitabread, I don't think you've seen this series of three evidences for cetacean evolution that I put together.
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If cetaceans evolved from terrestrial mammals we would expect to find certain things in addition to the characteristics that undeniably make them mammals.

From physiology we see that unlike fish and marine reptiles (see the ichthyosaur body plan), which move side to side, whales should move up and down just like their terrestrial counterparts do. Indeed, that is what we observe. A potential falsification would be if they undulated side to side and their flukes were shaped and positioned like those of Ichthyosaurs.

Based on the fact that we've observed atavistic legs on whales, we would expect from genetics and embryology to see that they retain anatomical or molecular vestiges for hind leg development. We observe both.

Embryonic dolphins develop limb buds that are absorbed back into the body as the fetus grows. (see photo at bottom of page)
Cetacean Palaeobiology

Cetaceans also have the gene package for limb development. In legged vertebrates, Sonic Hedgehog and Hand2 work together to develop them, but in cetaceans that gene package is non-functioning so the limb buds never develop unless there is a problem and atavistic hand limbs actually grow.
Developmental basis for hind-limb loss in dolphins and origin of the cetacean bodyplan

Press release here:
05 » How ancient whales lost their legs, got sleek and conquered the oceans » University of Florida
>> In all limbed vertebrates, Sonic hedgehog is required for normal limbs to develop beyond the knee and elbow joints. Because ancient whales’ hind limbs remained perfectly formed all the way to the toes even as they became smaller suggests that Sonic hedgehog was still functioning to pattern the limb skeleton.

The new research shows that, near the end of 15 million years, with the hind limbs of ancient whales nonfunctional and all but gone, lack of Sonic hedgehog clearly comes into play. While the animals still may have developed embryonic hind limb buds, as happens in today’s spotted dolphins, they didn’t have the Sonic hedgehog required to grow a complete or even partial limb, although it is active elsewhere in the embryo.

The team also showed why Sonic hedgehog became inactive and all traces of hind limbs vanished at the end of this stage of whale evolution, said Cohn. A gene called Hand2, which normally functions as a switch to turn on Sonic hedgehog, was shown to be inactive in the hind limb buds of dolphins. Without it, limb development grinds to a halt. <<

pitabread said:

Dolphins have both fully formed and various broken bits of olfactory receptor genes in their genomes. Yet, they completely lack an olfactory system and associated organs (i.e. they can't smell).

From an evolutionary point-of-view, it makes sense given that they descended from land mammals and their olfactory gene remnants are simply a part of that heritage.

From a special creation point-of-view, it makes no sense whatsoever. Unless the creator is a sloppy coder, cutting and pasting bits of genomes together and not cleaning up after themselves.

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guess what? some whales actually can smell very well:

How does a bowhead whale smell? Quite well, actually

"
Thewissen’s team found that the bowhead olfactory bulb makes up 0.13 per cent of total brain weight. “It’s similar to macaques and baboons. Those are animals that have a good sense of smell, certainly better than apes and humans,” he says.


To make the case for whale sense of smell even stronger, a colleague looked for genes in bowhead DNA that code for smell sensors. Half of the genes found seemed to produce proteins, compared with fewer than 25 per cent of smell-sensor genes in toothed whales. “I could not see how you can still doubt that bowhead whales can smell,” Thewissen says."

so once again we see why evolutionery prediction fails. and this is not the last time.

pitabread said:

Guess what? We're not talking about bowhead whales. We're talking about dolphins.

Anything to say about the dolphins complete lack of an olfactory system despite the presence of olfactory receptor genes?

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yes. it may be a degeneration. but degeneration isnt an evidence for evolution.

AV1611VET said:

You know what I found!?

I found that the same material the cover of my Bible is made of, also covers cows!

It seems to me that someone is using cow hides to make Bible covers!

Same genomes, same DNA, same everything.

Either someone is very frugal, or someone is operating on a limited budget!

All seriousness aside though: I think the term you're looking for is ontological reduction.

Wendy's said it best: "Parts is parts."

Click to expand...

I always wondered why the cow was considered sacred by some, but the question remains, what was first sacred the cow or the bible?

Or were you simply saying the Cow evolved frown the Bible or vice versa?

Or... #$^& ...never mind, I'm just so confused.

pitabread said:

Why else would dolphins have olfactory receptor genes with no olfactory system?

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again- they had it and lost it. the fact that some species of whales can smell prove it (dolphins and whales belong to the same group according to evolution). so again: no evidence for evolution here.

pitabread said:

(not to mention all the other physiological and genetic characteristics they possess, such as what USincognito posted).

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are you sure they are evidence for evolution? and if will show you that they can be explain by a designer model you will accept it?

xianghua said:

guess what? some whales actually can smell very well:

How does a bowhead whale smell? Quite well, actually

"
Thewissen’s team found that the bowhead olfactory bulb makes up 0.13 per cent of total brain weight. “It’s similar to macaques and baboons. Those are animals that have a good sense of smell, certainly better than apes and humans,” he says.


To make the case for whale sense of smell even stronger, a colleague looked for genes in bowhead DNA that code for smell sensors. Half of the genes found seemed to produce proteins, compared with fewer than 25 per cent of smell-sensor genes in toothed whales. “I could not see how you can still doubt that bowhead whales can smell,” Thewissen says."

so once again we see why evolutionery prediction fails. and this is not the last time.

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He didn't make a prediction, and he's talking about dolphins, not bowhead whales.

Armoured said:

He didn't make a prediction, and he's talking about dolphins, not bowhead whales.

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dolphins and whales belong to the cetacea group. so it's doesnt make any difference.

pitabread said:

Okay, so you don't disagree there is an evolutionary process at work here.



Sure there is. It perfectly fits with being descended from land mammals.

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if so how some whales can smell very well? did you know that even human have lost about most of its OR genes?

pitabread said:

What is this "designer model" of which you speak?

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any design in general.

Kenny'sID said:

I always wondered why the cow was considered sacred by some,

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LOL

pitabread said:

What doesn't make any difference?

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according to evolution both dolphins and whales evolved from a common land mammal. so if its true for whales its true for dolphin too. this evidence support the claim that dolphins lost their smell system. very similar to humans (about half of the OR genes of human are pseudogenes).