There's a crazy theory that human burial, as well as singing and dancing, are an evolutionary defense against large predators.

http://www.meltingasphalt.com/music-in-human-evolution/

That link is a blog length summary of a book, but the ultra-short version is: if local predators get a taste for human flesh from a corpse, they'll come after the living and humans singing and dancing in unision can give the appearance of one large animal to scare off predators.

Wouldn't the commonality of singing and dancing be much more likely the result of it being a social behavior, and social behaviors increasing the odds of reproducing? This is true even today - dance clubs are still one of the best ways to meet women as a man.

If you're only after sex this is true.

Evolution IS only after sex.

I would argue it's after reproduction, successful reproduction that also has successful reproduction even.

Why do grandparents love their grandchildren? Something noble about human nature and love? Or is it evolutionary advantageous?

From my own observations, the relationship retriggers the parenting motivations / dopamine. With the added benefit that you can put the darn thing down at the end of the day and walk away.

From my own observations, the relationship triggers nothing like parenting. There's no feeling of parental obligation, outside of love for that child. So, tell me, why would that evolve in people?

Because old cave-people aren't as good at hunting and gathering, and can be better used as child-care cavepeople.

And survival, and the survival of offspring. Why does menopause exist if evolution is only after sex?

To stop those old, damaged eggs from generating more springs? Perhaps the cell quality decreases as time passes by, and it's better to set those men free to get new ladies, with new eggs.

Why on earth would it be evolutionary beneficial -- if evolution is only after sex -- for a creature to forgo passing on her direct genes in favor of letting another creature pass on hers?

9/11 showed that after great death comes great live.

We like to flatter ourselves that human flesh is super tasty and drives predators into a feeding frenzy. Why should it be?

It's not necessarily tasty, but it isn't super fast, we're not venomous, poisonous, spiky, or armored, we can't smell very well, our claws and teeth are relatively ineffective, our young are pretty defenseless for several years and we only have a few of them...we need all the inventiveness and precautions we can come up with to not be the easiest meal in the forest. Predators don't really care about tastiness, they just need to feed.

...just soft and pink.

https://s-media-cache-ak0.pinimg.com/736x/58/64/15/586415bb9...

With all this in mind we still made it to the top of the food chain(not using the scientific term). What we lack in physical prowess we more than make up for in intelligence and our ability to use tools.

Not just intelligence but also endurance when traveling long distances.

Basically intelligence + long distance running = ability to track prey.

I don't believe that it is a matter of being "super tasty", but rather, one of not wanting to inform predators of an easy to access food supply.

This sounds a lot like why horse mares will eat the placenta from their foals after giving birth. Foals are born able to run, but they're nowhere near as strong as a mature horse.

I was under the impression they ate it because of all the vital nutrients that the placenta had, but I dont think anyone had conclusive evidence except in an evolutionary biology hand-wavy way.

If that were the case we should expect health problems from horses that go too long between pregnancies, yes? Otherwise the nutrients are not "vital."

Whence do you suppose the nutrients in a placenta originate?

Actually everything in this thread is a just-so story. It's pretty silly to pick out one specific rare behavior as even relevant to evolutionary fitness. How would any of this be tested?

I dunno, if you have been gestating a foal, you might be a little undernourished at the end of the process, so a placenta's worth of nutrients might then be "vital."

Well that all depends on what kinds of sauces you have at your disposal.

I feel similarly. However the article notes:

> Having the bodies would help the families grieve, and would also help to prevent lengthy delays to insurance and inheritance settlements.

Risking lives to recover dead bodies does not sound logical and yet it's the norm on underwater accidents. One of the multiple examples of a recovery gone wrong is the case of David Shaw [1], particularly famous because there's footage of the recovery accident.

[1]: https://en.wikipedia.org/wiki/David_Shaw_(diver)#Last_dive

> Risking lives to recover dead bodies does not sound logical

You're a green-blooded, heartless monster, Mr. Spock ...

It does not sound logical. Every time there's an underwater accident (including plane/helicopter accidents and shipwrecks), popular sentiment is on the same line: "why put lives in danger for dead ones" so there must be another reason for sending divers down there (other than feeling logical or not):

- Something related to body identification and insurance.

- Human life is cheaper than ROVs.

- There are tasks that ROVs can't accomplish.

One of the reasons is the bond between the living who continue the dangerous pursuit. It is a statement between them that nobody gets left behind. That is the level of commitment needed; unequivocal and unending.

It's interesting to contrast this with mountaineering, and the many corpses pointing the way to Everest's summit. Some have nicknames.

Shaw's story: http://www.outsideonline.com/1922711/raising-dead

Surely an ROV could be tasked to this effort (at least for the identification part for insurance).

How would the ROV be controlled? Radio won't work. Long cables are problematic in cave environments, they snag, they get pulled by currents.

There are wire guided torpedoes and missiles that carry a spool with them and pay it out as they travel. Presumably this is a good thing because it can't be intercepted and jammed. Anyway, that missile carries 4200m of wire, which would be plenty for an ROV to explore most of the cave in the article before sending people, who could follow its wire.

https://en.wikipedia.org/wiki/BGM-71_TOW

You can't touch the sides in cave diving. It generates silt which destroys visibility.

Yup that's fine. If the ROV kicks up any silt, shut it down and go for lunch. Nobody's air is running out so you have extra time.

There's no current down in these caves. The logical solution then is to drop a trail of breadcrumb beacons to relay your signal along, either via light or some radio band that penetrates water halfway decently.

Are you certain? I've spent most of my dives in Florida springs, which can have flow rates above 100 cubic feet per second. You can basically get blown out of Devil's Eye at Ginnie Springs if you're not careful with your trim when ascending.

The downside of still systems is that any silt you stir up can kill the visibility for hours / days, which would cause problems for light-based beacons.

I wonder how much bandwidth a sonar link can provide over reasonable distance.

The a highly restricted, complex cave environment with echoes all over the place? Probably not much.

I suspect you could use the echoic environment to your advantage with a MIMO type system.

The ROV can drop an amplifying transceiver every so many meters?

How do divers communicate over long distances? If they don't, that's something worth solving in its own right. If they do, couldn't the ROV use the same thing?

Light signals. You can say 3 things over any distance, which are "OK" (as a question or a response), "attention please" and "OMG OUT OF GAS NEED HELP IMMEDIATELY".

Given clear visibility, which gets rarer and rarer with distance - and even more so in constrained spaces, which are unlikely to be pure bedrock. Also, line of sight.

Indeed. So you see operating a ROV like that is a non-starter.

I never said otherwise; are you sure you are not replying to somebody else?

They don't. GL;HF.

Also, cultural: Finns also have a proud history of going to great lengths to retrieve the bodies of deceased friends.

This wasn't sentimentality, it was just adrenaline junkies justifying themselves.

I really do get why people cave dive and do dangerous things. It's a lot of fun. But really, at the end of the day, they did this because it was a rush. There's no other rational reason to do something to risk your life doing someone your friends just died doing for no other reason than it was exciting.

lol, go ahead and downvote. I do a lot of adrenaline rush type activities, but I've never tried to pretend it was anything other than just dumb, life risking adrenaline pumping distraction from life.

A couple of years ago someone died on a mountainbike trail I use. This can really spook people, even those of us who didn't know the guy. Ultimately people want that feeling to go away and be able to enjoy the sport without such things hanging over them. It felt like people wanted closure so that the fun could continue rather any deeper sentiment.

Also I think that these sport are about more than just adrenalin. There is joy in mastering the difficulty without getting a rush.

"But really, at the end of the day, they did this because it was a rush"

Diving isn't really compatible with "a rush", especially not cave or other technical diving. You have to be focused, methodical and patient. It's more meditative than anything, you can't even breath too quickly without risk. While still having to keep track of a lot of things. In "rush" type of activities it's the sensation of almost losing control that is fulfilling, while in technical activities like this it's rather the sensation of being in control.

Not a diver myself, but I cannot imagine you could do any diving, and particularly this kind of diving, in an adrenaline rush. The fascination must be much, much deeper.

For cave divers, I am convinced that the other divers would quickly dispose of a team member who looks like he (or she) is not acting super calm.

so what is life, if not some boring stuff around adrenaline pumping distractions? you do not hold the key to the proper way of living other people's lives.

sorry for my bad english and for feeding a troll.

I wish people think twice before calling troll. That word has so lost it's original meaning, and is now a days used to shoot down any dissenting opinions.

I say this as someone who 100% agree with the first part of your comment.

I think you are right. My troll detector was triggered by the request for downvotes.

I scuba dive, and I am definitely interested in cave diving. I will tell you that I am not at all doing these things for any adrenaline rush, in fact scuba diving feels like such a slow paced and calm sport that I do not even think of it when I think adrenaline rush. I've also done skydiving. Skydiving I would definitely consider an adrenaline junkie kind of sport though and am happy to admit this.

I no longer skydive. I switched because I find the joy in exploring the underwater, a place that most people never get to see. And exploring caves is something that VERY few people ever see, and that is a truly amazing experience.

Soldiers in various armies share some similar traditions: not only do people risk injury or death retrieving wounded comrades; they even do it to recover the bodies of dead comrades, so that the body can be sent back to the family.

Finland was unusual in the context of WWII that all bodies of dead soldiers were retrieved if at all possible, and sent back home, not just buried at a local military graveyard. This diving thing (Finnish divers in a Norwegian cave) has echoes of the same.

Also note that the people retrieving the dead in both cases are in the same group as the dead, risking their lives in the same way. They have presumably thought about the possibility that they will die in the same way, and the idea that someone will retrieve their corpse and return it to their loved ones probably brings them a great deal of comfort.

You can just chalk it up to culture, but there is also a logic to it that is every bit as logical as the "leave my meat where it falls" crowd: if you have a culture of retrieving the bodies of the fallen, no matter the difficulty, then that means that you won't leave behind the wounded to save your own skin. This, in turn, makes it easier to trust and to risk your life for your comrades -- they'll take care of you in turn, living or dead.

Another reason for extracting dead bodies in a war is to avoid them being mutilated and used for propaganda by the enemy.

Is that a legitimate concern? During war-time, I would assume the body's of your enemy would be plentiful.

I always assumed the "no man left behind" spoke more about the excessive abilities of the group. (We are so powerful that we can even overcome our enemy to retrieve our fallen men.)

> During war-time, I would assume the body's of your enemy would be plentiful.

In fact, when for instance Taliban or Daesh look at things, the enemy bodies are not plentiful at all. I think it is extremely rare for an American, British or NATO partner soldier's body to fall in their hands. The Western losses in those wars are very small by historical standards, almost negligible, and evacuation is extremely efficient.

For instance, take the current Afghanistan war. Wikipedia: "As of October 1, 2015, there have been 2,326 U.S. military deaths in the War in Afghanistan. 1,856 of these deaths have been the result of hostile action."

1,856 casualties from enemy action in about 15 years. That is about the same number of casualties as Omaha Beach took in a single day. It's half of what my father's brigade inflicted in a single day against one single Russian infantry regiment in February 1942. It is one thousandth of what German Feldheer suffered in all of WWII, and one five-thousandth of what the Soviet army suffered in their "great patriotic war" during four years.

Casualty numbers in modern wars where Western troops attend are very small, when compared to historical wars.

The current Syrian civil war is then another matter. Its casualty numbers are not big when compared to WWII, but they are much bigger than Afghan or Iraq wars.

[My previous comment was of course wrong in the sense that US, UK and NATO troops are not the only enemies that Taleban or Daesh have. Other combatants - be it the Afghan army or Kurdish troops - that fight them do suffer more casualties. But also the propaganda value of those other enemies, when dead or alive at their hands, is much smaller.]

It's also a way of telling troops that if you get stranded, we'll even come and rescue corpses, so never give up hope.

It's mostly a propaganda things, but in special operations (from were many things in the military gets appropriated) it has a purpose. Which isn't about "comfort" as some has suggested, but rather about accountability. If you don't speak up about something and someone gets in trouble, you will have to go and get them. Which works both ways. But also if you make a mess, your friends will have to risk their lives (more than usual) to come get you and that is a horrible rather than comforting thought.

It's basically "we are all in the same boat", which is true (sometimes literally) when you're engaged in high-risk activities. Note that high-risk in this case doesn't mean that you might get killed, but that there is a low margin for error leading to catastrophic failure. Special operations are not about being a fair fight, it's about using your advantage and once you loose that you're often in big trouble.

Say you're doing recon on enemy territory and calling in airstrikes. You're a small mobile force that is hard to find having disproportionate impact on the battle, which is good. Then someone drop a glove or breaks his leg or anything else that compromises the mission and now you're just a small force soon to be a disproportionate loss, which is bad.

It's probably not a legitimate concern between two advanced regular militaries who follow the laws of war and would bury your dead with respect if they can't actually return them to you, but if you left a uniformed western body where ISIS can get it then I'm sure that would end very nastily indeed, with photos on social media and so on. Think of the military contractors burned and hanged on that bridge in Iraq.

'No man left behind' is practical, both for the propaganda reason above and unit morale, not about showing off. But like most things in military life I never heard anyone ever bombast about 'no man left behind' like they do in the movies.

"hey, soldier, go on this risk thing because everybody will be looking for you. Yes, we are a team!"

One reason to not do that is to avoid the "wound a soldier, kill the rescue party" trap, or the boobytrapping of corpses.

That's actually the plot of a Bosnian movie No man's land.

They wanted to recover for 2 reasons:

1) Speed up post-death admin (insurance etc) 2) Unblock the route for future use, they did not want to see the system closed.

Those are the practical reasons - there are numerous mentions of a culture of "leaving no one behind".

on top of all mentioned - bodies were blocking the way through. in cold waters it would take years to decompose and all equipment would be still there making passage much more dangerous/impossible.

The ability to grieve for the deceased is an intrinsic part of the healing process that needs to happen, after death rips a person from the fabric of their loved one's lives.

The dead body allows for death, in all its unknown shock, to be visualized and thus integrated into human experience. A link from the living to the gone, that allows grieving to heal the social wound of a death.

About the only logical thing I can think of is that it gives certainty. Without a body, there is always the possibility that they just wanted to start a new life elsewhere and their friends are covering for them. Or maybe they were saved by mermaids or...

Dead or alive they are still your friends, family, coworkers, etc. You take care of each other no matter what. Thats it.

>Dead or alive they are still your friends, family, coworkers

I think that's the main idea at issue here: Are they still those people? Or are they just, to oversimplify a little, just some old meat?

Your body is as much part of you as your mind/thoughts/consciousness. Just like a battery is still a battery even after it holds no more charge. It's not a piece of metal but a battery. A dead one at that.

I think it's arguable that a battery that can no longer be charged is a "battery". At best it's a "dead battery", and you'd be annoyed if someone sold you the latter as the former. Analogously, I would not call Bob's dead body "Bob", but rather "Bob's corpse".

It's kind of a dumb philosophical argument though. We all know what's really going on, so it's pointless to argue over words.

It might be (waaay) outside the scope of the usual discussions around here, but I don't know that it's pointless. I'm an atheist, and I'm totally fine with the idea that when I die, that's it, I'm as dead as any other organism.

Still, though, I've got strong opinions about how I want to be "disposed of" when I die. Burial evokes strong emotions for me, and I can't for the life of me figure out why. Even in games like Fallout, I try not to leave corpses just lying in a river or in a shrub or something, even if it was somebody who was just trying to knife-murder me. I accept that it isn't a person anymore, like I said in my previous comment, but I still have a sentimental attachment to the... husk.

I'm just reading Dawkings Selfish gene and it attacks pretty fiercely against "group selection". But I find it impossible idea that any part of human behaviour could be completely detached from genes. And especially weird if Human behaviour could influence genes, wihtouth anykind of feedback from genes back to behaviour.

How can you explaing phenomena like this withouth group selection? From selfish gene point of view, a brain that is even capable to think about risking life to fetch dead body of friend* should be strongly selected against.

* (and therefore some individuals might act on it very occasionally)

It's worth pointing out that The Selfish Gene is kind of old, and is by no means the last word on evolutionary biology.

https://en.wikipedia.org/wiki/Group_selection#Group_selectio...

>Since the 1990s, group selection models have seen a resurgence.

In this case I think there was a practical purpose behind the retrieval - the body was preventing further exploration of the system. Well of course the sentiment makes sense, and the Finnish have a long cultural history with this form of retrieval, but don't discount the practicality of it. Dead bodies really stink up the place something foul.