Why did whales, as mammals, lose their heterodonty? What's the benefit of not having canines or molars?
Why did whales, as mammals, lose their heterodonty? What's the benefit of not having canines or molars?
Why did whales, as mammals, lose their heterodonty? What's the benefit of not having canines or molars?
This thread made me learn that Narwhals are actually toothless (except for the obvious horn-like tooth in males) and instead create a vacuum to suck in prey
i love seeing creationists start troll threads and then get thoroughly BTFO
Their molars were meant to cut, not chew.
Because their food source changed over time.
I don't understand why this concept could be seen as complicated.
>I don't understand why this concept could be seen as complicated.
he wants to know why their food source changed over time when the old food source is still easier and more prevalent than the new one.
and the answer to that is complicated.
Because their food source changed over time. They are just as much a part of evolution. Not that complicated.
You're upset that a species re-adapted to an environment that they already came from? Bro, some of us still have gills when we're born as humans. They are the pinholes in peoples ears, when they are expressed. Evolving new things is complicated, yes; re-developing things we already had is child's play.
You answered your own argument; nature isn't perfect. If people ask why things aren't perfectly adapted to an environment, the simple answer is that they might still be adapting. Things aren't finished, just because we're observing them right now. They are always still undergoing changes.
Again, this isn't as complicated as you want it to be.
>Because their food source changed over time.
it didn't though. The food they used to eat is still all over the place, and much easier to hunt than what they currently eat.
>re-developing things we already had is child's play.
even OP knows that's not true.
>You answered your own argument
not my argument, and your explanation contains the same childish understanding of evolution that OP's question does.
nature doesn't optimize. It's not in the process of optimizing, and whales will never be perfectly adapted to their environments. In fact as an animal adapts it becomes much more limited in which environments it can choose from. Whales adapted to life in the oceans, meaning they're never going to be adapted to life on land or in the air ever again. They will go extinct before that happens.
He also wants to know exactly how homodonty evolved, complete with intermediate examples in an orderly procession over time.
which is impossible because that's very likely not how it happened at all. Replication or addition of a fully formed organ is the product of a simple genetic repetition, not slow evolution over time.
when reptiles evolve a higher or lower vertebrae count they don't evolve a completely new vertebra, they simply repeat a gene coding for an existing vertebra. Teeth can be replicated in the same way, and in some cases presumably were.
Finally he asks why they're not perfectly adapted to the new food source. The answer to that is simple enough, evolution doesn't produce perfect adaptation. But the reasons for that are quite complicated and there's a lot of them.
if they'd need them, they'd still have them
We explain evolution in terms of beneficial adaptations when speaking to children and morons, because that's the very simplest way of explaining it. Not because it's true, but because you're too stupid to understand anything more complex than that.
Hope this helps.
>we
Your post made me smile. We who? The wikipedia-enlightened? Reddit?
Some have the knowledge and humility to acknowledge their inherent ignorance of the ways of the universe, while others possess the baffling arrogance to claim a near complete understanding of the ways of the world, which they don't considering the future as well as the part is a mystery to them as much as any other.
>We who? The wikipedia-enlightened? Reddit?
Adults of sound mind with more than a passing interest in biology.
I never claimed complete knowledge of the universe, simply knowledge that OP is starting from a childishly simple view that produces false questions. This is normal on Wauf because OP is a moron and he posts a significant fraction of the threads and comments here. It would be odd to find more than one adult with such naive views of their area of interest in any group outside of a mental hospital.
His use of the term "heterodonty" indicates more than a passing interest. His presence here indicates he's an adult, and his posts over the years indicate he's a fairly old adult. So it indicates a certain deficiency when an adult with a solid interest in evolution displays such childish assumptions about it. Neither of us can hope to know everything about evolution, but I can easily assure him there are entire universes of knowledge he's unaware of.
Nta but I'm a molecular biologist and I don't go around explaining evolution and covid and the various vaccines because I'm not an expert on that. But I'm inclined to believe actual experts on the field because I learned to trust the science despite its flaws. And yes evolution is unfathomably more complex than popscience, youtube and anonymous posters are able to explain. My fairly uneducated main take is that people usually assume that evolution has some kind of direction it wants to follow when in reality it doesn't have any kind of agenda. Its mechanisms just lead to every available niche on earth being filled with life.
Enlighten me, then, as to why an aquatic mammal would no longer need molars, expertly designed to masticate and crush things. There's no shortage of hard stuff in the oceans to chew on.
Enlighten me also as to why they would no longer need canines, projecting fangs perfectly designed to snag prey and small things. There's no shortage of small and slippery prey in the ocean to chase.
Remark also, in your wisdom, on why there seem to be no teeth at the very forefront of the jaws, if chasing slippery prey like fish were to be the sole reason for the lack of heterodonty in these animals. One would assume that conical incisors at the front of the jaw would be perfectly suited for such a thing but instead we find a rather prominent gap here, separating the rows of teeth in both set of jaws.
And considering you know all, might you also shine some light on the exact biological mechanisms by which cetacean teeth gradually became uniform, how molars receded and incisors vanished until all these mammals were left with appear to be four rows of nearly perfectly uniform conical teeth in the upper and lower jaw.
Explain how this reflects on other marine mammals as well. Is this adaptation an inherent benefit, bound to be repeated? Will we see inevitable examples of convergent as different groups of mammals take to the sea? Will seals inevitably go the same route? Otters? Will all mammals who chose water over land inevitably lose their molars? Surely, if it's SO logical that cetacean teeth lost their heterodonty, you must have some sound theories on these developments happening again in the future.
More childish adaptationist nonsense
you love attacking strict adaptationism, which is itself the model of morons and children. Meaning you present a straw man. You question a view that biologists simply don't hold.
1. Organs are expensive to maintain both physiologically and genetically
2. Organs are often lost, and that loss persists within a population if it doesn't ruin the organism's ability to reproduce.
3. Loss of organs generally occurs via either genetic drift or simple deactivation or deletion of genes
4. Organs often get lost during the life of the organism, and many organisms cope with this by changing their niche rather than dying.
5. Changing behavior to compensate for a lost organ isn't strict adaptation, it's an example of the organism adapting to itself rather than the environment.
6. Organs once lost are difficult or impossible to regain in their original form
7. Replication or deletion of a fully formed organ is accomplished via genetic replication and deletion rather than fully evolving a new organ.
8. Organs gained are not always or even often the best possible organ for a task or environment. They simply must be sufficient
9. Organisms over time adapt to their environments, but they also change niches to adjust for maladaptive changes in their body, and over time build up as many maladaptions in the form of lost organs as they gain new adaptations
10. Highly adapted organisms tend to go extinct because of too many maladaptions that cannot be reversed
11. A loss or gain of an organ needs to only meet some need or lack temporarily, and may not make any sense in other times, places, or niches.
12. While evolution does tend to produce repeating patterns, they don't always exist for the same reasons, or for any reason at all.
13. Predicting how current organisms will evolve in future based on how different organism evolved in the past is impossible because it requires predicting both environments of the future as well as physiology and behavior of future organisms. The possibilities are basically infinite and the outcomes decided in chaos.
Pure fan fiction
You clearly underestimate how much crab sea lions eat. They absolutely gorge themselves on the critters.
Imagine being this far up your own ass.
moron
Explain what you mean. Not that anon.
What is it then, if not beneficial adaptations?
t. Someone that just opened his first evolution thread on Wauf.
>If evolution produces the best possible organism for a situation, why don't humans have wings and gills in addition to hands and lungs?
>surely that would be better?
evolution doesn't produce the best possible adaptation, it produces a good enough adaptation out of the relatively few possibilities available to the organism.
Often it produces horrible maladaptations, and organisms learn to deal with it or go extinct.
That makes sense, anons, but I mean, I already understood that. But that's still adaptationism, isn't it?
Along with a few other factors.
What's wrong with OP's post, considering all that?
And thanks for explaining.
>What's wrong with OP's post, considering all that?
OP assumes the loss of an organ must have some benefit and then argues that it does not.
a creationist gotcha type argument.
the premise itself is false. Loss of organs often has no benefit. Replication of organs often has no benefit. Or if beneficial it's because the animal changed its behavior to adapt to itself, not its environment.
>What's wrong with OP's post, considering all that?
>if red cars get pulled over for speeding more often than blue cars, why isn't a red honda faster than a blue ferrari?
OP poses a childishly stupid question that ignores a shitload of variables and complexities in reality.
Assuming he's over the age of 18, such a question indicates a defective mind.
>such a question indicates a defective mind.
c.f. autism
Hyperfocus on one data set (strict adaptation) to the exclusion of other dependent data sets (Gouldian spandrels, atavisms, genetic drift, maladaption, behavior adaptations, etc.).
this hyperfocus results in conclusions that are narrow, lacking in nuance, and generally incorrect when the errors are repeated several times to arrive at a conclusion.
>autism
The alternative is that OP is a new person that somehow was exposed to the word "heterodonty," and knows that cetaceans evolved, lost, evolved, and lost it several different times,
yet somehow has never been exposed to the most basic concepts of evolutionary theory.
but there's no need to posit such a rare and unbelievable character stumbling into Wauf when we have exactly that sort of person living here 24 hours a day 7 days a week constantly posting this same sort of drivel.
>Hyperfocus on one data set (strict adaptation) to the exclusion of other dependent data sets (Gouldian spandrels, atavisms, genetic drift, maladaption, behavior adaptations, etc.).
mainly indicates worse abilities for logical thinking, not autism
Basically it's a constant feedback loop between the organism, its own body, its behavior, and its environments. And all of those things are constantly changing. Looking at how an organism adapts to its environment or niche ignores how it adapts to its own body and genetics. It also assumes the environment is static and the organism changes, or the environment and organism change but the changes are always beneficial or occur fast enough. In reality the dance between organism, genetics, niche, and environment is much more complex than an adaptationist can imagine, and it isn't always or even often beneficial to the organism. Organisms go extinct constantly because they simply can't produce beneficial adaptations as fast as environments can change, or niches, or genetics.
or to sum it up,
The vast majority of organisms that have ever existed are extinct, because evolution over long enough time spans doesn't produce beneficial results most of the time.
I see, that makes sense. Thank you.
Because conical teeth are the best for grabbing slippery prey like fish which most species eat whole (no need to chew with molars or gnaw with incisors)
likely due to being so large all they have to do is swallow or crush things to death
Orcas are known to take on prey larger than themselves though. Do you think thats a relatively new thing in cetaceans, and all whales leading up to this point have been almost exclusively feeding on smaller animals like fish?
Orcas don't have molars for the same reason crocodiles & alligators don't have molars: they don't chew their food, they just grab, rip & tear off large chunks that they swallow whole. Orcas mostly eat seals, fish, and squid, but will also go after other whales, sharks, and birds if they're feeling frisky.
Pic related is a bunch of other toothed whales. If you'll have a look at their teeth you'll notice they're all fairly similar- pointy and designed for gripping food and swallowing it with now molars. The river dolphin in the corner there practically has a beak their jaw has become so specialized. The only exception is the beluga whale who actually *does* possess some flat grinding teeth and that's because they still eat crab and shrimp.
>that's because they still eat crab and shrimp.
are you sure they don't eat crab and shrimp because they have flat grinding teeth?
The problem is the animal probably didn't start eating food that you imagine needs chewed and then grow the organs to process it.
the flat teeth had to exist before the crab chewing, assuming crabs need chewing. And that would indicate that the animal didn't adapt to its environment, it merely changed its form for no reason and then changed its behavior to match the new form. Crab eating didn't cause flat teeth, it was the other way around.
>are you sure they don't eat crab and shrimp because they have flat grinding teeth?
Yes, because we've seen this kind of specialization in seals. Which is probably a better example.
Seals are in the Carnivora family, so they were made out of some kind of dog-cat-bear-thing originally, before becoming seals. If you look at the picture I have here you can see the similarities between the seal and the dog skull opposite to it. Meanwhile, you have a walrus skull on the other end. The walrus is related to the seal, but it's gone through a number of dramatic changes and one that included grinding teeth- the walrus eats shellfish and isn't a big fish-eater.
>The problem is the animal probably didn't start eating food that you imagine needs chewed and then grow the organs to process it.
I think there's a miscommunication problem going on here that I'm going to try and rectify:
You don't need perfect grinding teeth to eat shellfish, crab, etc.. But you eventually develop them if you're going to eat nothing but crab, or majority crab/thing with a shell.
If you have dog-like teeth like the seal has then you don't actually *need* to have grinding, gnashing, molars unless you're going to devote your life *to* eating nothing but crab/shellfish. The dog-like teeth in the seal's mouth are good enough for a variety of foods.
/thread
(You)
>The walrus is related to the seal, but it's gone through a number of dramatic changes and one that included grinding teeth- the walrus eats shellfish and isn't a big fish-eater.
Part 2'ish, but this also becomes more evident if you see the timeline for the walruses' development. You can see a clear line/group/deviation where it decides its' going to "commit to the bit" and begins getting interesting looking rather quickly.
That blooger looks so happy
>The only exception is the beluga whale who actually *does* possess some flat grinding teeth and that's because they still eat crab and shrimp.
Belugas don’t have flat teeth, that’s just something seen in captive whales where their teeth have been ground down by chewing on the concrete walls of its pool. You can see the same thing in captive orcas