Paleontologists are trying to understand why the fossil record is mostly males

https://www.atlasobscura.com/articles/fossil-record-prefers-males

by jelliclesfarm • 6 years ago

119 101 6 years ago

jjtheblunt2• 6 years ago

Since fossils are largely bone, is it related to osteoporosis being more prominent in females (usually)?

bigbubba2• 6 years ago

AFAIK bone loss occurs with age in both men and women, but accelerates for women after menopause. But did female dinosaurs have something like menopause?

simonh• 6 years ago

The article is about mammals, not dinosaurs.

ska• 6 years ago

Do we know much about osteoporosis outside of humans, let alone dinosaurs? Seems to be a bit of a jump.

giantrobot• 6 years ago

Fossils aren't bone. They're mineral deposits in the space the bone used to be. In rare cases there might be some original tissue but for the most part fossils are formed from sediment(?) infill. Preserved bones are...bones and not fossils. Think of fossilization like lost-wax casting.

jjtheblunt2• 6 years ago

Excellent point. I hadn't thought of it, but knew it as a kid, when I read your comment.

kazinator• 6 years ago

fossil record is mostly males

tyrannosaurus, mammoth, ... da Vinci, Bach, Newton, Euler, Maxwell, ...

sturza• 6 years ago

fossil record not fossil fuel

sillyquiet• 6 years ago

This phenomena was covered by the excellent pop sci channel PBS Eons a while back.

https://www.youtube.com/watch?v=fr0Ifw8TJVw

fedxc• 6 years ago

The article was written in Sep 2019 while the video was uploaded Nov 2019.

I love this article because it provides scientific evidence for something I already knew or suspected: males take more risks.

I also think this video helps illustrate why fossils are mostly male: https://www.youtube.com/watch?v=674IFkAj_1s

mc324• 6 years ago

Why do they even have to say this:

” This has less to do with misogyny than with prehistoric herd distributions...”

It’s like stating that water is fat free. It kind of spoils the article.

phkahler• 6 years ago

Later they offer this:

> This wasn’t a surprise, based on what Pečnerová had theorized about mammoth herd behavior, since bison social structure similarly isolates young males. “By [the mammoth] anology, some of the male bison are going off and doing stupid things,”

Which could be interpreted as misandry even though they blame the males for their fate in the same sentence. :-)

mc324• 6 years ago

My complaint is the anthropomorphization of animals.

Unless we know what drove animal behavior, we cannot make such attributions.

It would be like saying dinosaurs raped each other. From a human perspective their mating behavior if we knew it might look negative, but we cannot attribute intent to animals like that.

tomjakubowski• 6 years ago

It's a joke.

progval3• 6 years ago

They probably meant misogyny from today's archeologists rather than from bisons and mammoths. There are known instances of gender stereotypes influencing archeological discovery. For example: https://www.nationalgeographic.com/news/2017/09/viking-warri...

Since the remains were found alongside swords, arrowheads, a spear, and two sacrificed horses, archaeologists had considered it a warrior’s grave—and, thus, a man’s.

mc324• 6 years ago

Even with that possibility it’s ridiculous. It would require a conspiracy by archeologists (of both sexes) to only find male specimens (as if there are so many that they’d ignore female specimens just to be misogynistic. How realistic is that?

It also primes the reader to think “aha misogyny!” where it isn’t. Just as saying fat free water!

simias• 6 years ago

Frankly I think you're reading what you want to read here. I get that those are hot button issues for many people but here I really think it's just a small joke because, as you point out, obviously the distribution of fossils has very little to do with gender politics.

That being said if you want to take it more seriously sometime sexist bias does taint research in unexpected places, such as expecting that certain tools would've been used by males instead of females for no real reason for instance. It's important to be aware of these biases if you want to do good scientific work I think.

coldtea• 6 years ago

That being said if you want to take it more seriously sometime sexist bias does taint research in unexpected places

Similar to lets-discover-sexism-everywhere bias in social sciences though. In general soft sciences are prone to the ideology of the day (which is also what gets you grants)...

bluntfang• 6 years ago

It kind of spoils the article.

Man if that spoils an article for you, you must live a pretty miserable life.

Not surprised a comment like this isn't dead on this site. It adds nothing to the discussion, and it seems like OP didn't even read the article and is flame baiting.

JoeAltmaier7• 6 years ago

Or, do they have it wrong, sexing creatures? Seems the far simpler explanation.

Further the 'explanation' that males might have taken more risks, explains nothing. The one common denominator between every single mammal from ancient times is, they are all dead. It doesn't matter how; all their skeletons should be somewhere in the fossil record. A disparity would have to explain how male skeletons died in precisely the right way to be preserved more often. Which seems like nonsense.

daenz2• 6 years ago

Further the 'explanation' that males might have taken more risks, explains nothing.

It does though:

Luckily for paleontologists, some of these death sites—bogs, crevices, lakes—are pretty good at preserving remains.

JoeAltmaier7• 6 years ago

And how about the locations female Mastadons choose for giving birth, raising calves - do they preserve remains? The OP seems a careless off-hand analysis, if it doesn't go more than skin-deep into behavior differences.

metalliqaz• 6 years ago

"It doesn't matter how; all their skeletons should be somewhere in the fossil record."

This is false. Most skeletons decompose. Only some happen to end up in the right spot to remain intact long enough to become fossils. Also, these mammoth remains aren't fossilized, they aren't old enough. These are just remains that have been preserved.

JoeAltmaier7• 6 years ago

Ok, how about "represented in equal numbers in the fossil record". Leading to the main point: why would male skeletons happen to be preserved more often? Any ideas? That involve science, not guesses about impossible-to-measure Mastadon behavior.

turbohz• 6 years ago

Typical "I know more than the experts" answer.

qeternity2• 6 years ago

Worse than that. This is “I can use basic, uninformed reasoning to work through a complex, highly domain specific problem”. Usually people who think they know more are at least able to face the facts when it’s clear that they don’t. This group of people know that they don’t know as much, but believe their “superior” intellect can’t make up for it...

JoeAltmaier7• 6 years ago

No, its a typical thought-provoking "Why haven't they addressed the central topic?" Just some hand-waving. Without understanding Mastadon behavior male vs female, there's no conclusion to be made.

chrisseaton2• 6 years ago

all their skeletons should be somewhere in the fossil record

Why do you think this? It is not a true statement.

Not all skeletons get fossilised - it requires a fairly particular set of conditions. It may be (likely is according to the people studying it) the case that males got into these conditions more frequently than females.

JoeAltmaier7• 6 years ago

I guess the article claimed that. I'm wondering, why? I'd like some actual science.

daenz2• 6 years ago

TL;DR The current best hypothesis:

They figured it was more probable that young male mammoths were much more likely to travel solo, away from the wisdom and protection of matriarchal herds, similar to the way elephant societies function today. In other words, these male mammoths—young, reckless, foolhardy—were just more likely to get into some kind of trouble and die, from getting stuck in a pit to running afoul of hunting humans. Luckily for paleontologists, some of these death sites—bogs, crevices, lakes—are pretty good at preserving remains. “They were more likely to do silly things, like die in tar pits,” Gower says.

bilbo0s• 6 years ago

I don't know man?

Running afoul of hunting humans should leave fewer remains than, for instance, an elephant graveyard. Now it's possible mammoths didn't do the graveyard thing, but the point is the humans would have left far less of the animal than an elephant grave or a bog.

coliveira• 6 years ago

Elephants and other animals don't leave graves. They just die and decompose on the surface. That's why you won't easily find a graveyard for animals, unless they happen to be buried by some accident.

openasocket3• 6 years ago

The elephant graveyard thing is actually a myth; elephants do not seek out some specific location when they sense death is near. In fact, one of the theories I’ve heard for how this myth got started was European explorers coming across sites where the local elephant hunters stockpiled their bones and ivory, and assumed this was a natural phenomenon.

bigbubba2• 6 years ago

There are instances of humans assembling mammoth bones into some sort of structure: https://www.smithsonianmag.com/science-nature/60-mammoths-ho...

25,000-Year-Old Structure Built of the Bones of 60 Mammoths

According to the article, similar albeit smaller structures have also been found across Eastern Europe.

ravi-delia• 6 years ago

It does seem like contact with humans wouldn't leave much in the way of remains (plus wouldn't humans go after less reckless prey?), but definitely tar pits and the like would be more likely to snare a risk-tolerant and solitary animal than a risk-averse one in a group.

estaseuropano• 6 years ago

If you read further in the article, they mention this explanation is not enough as that doesn't apply to all mammal species.

astrophysics• 6 years ago

The white, male patriarchy!

ajkjk2• 6 years ago

Is it possible there were just a lot more males?

seph-reed4• 6 years ago

Seems unlikely. Honestly, I'm surprised that the male to female ratio is anywhere near 1:1. Every male baby is one less womb, and one less branch on the evolutionary tree.

Does anybody know why it's so close to 1:1 instead of women outnumbering men? Specifically in non-pair-bonding species?

ludston• 6 years ago

There is some sort of math behind why a 1:1 ratio is almost always selected for. It intuits like, if all of the other elephants are breeding 1:2, and you breed 2:1, you will be significantly more likely to spread your genes.

staticman22• 6 years ago

I just googled it out of curiosity and I gather from Wikipedia, if a species has more females, the families with male children will reproduce more than the families with female children, and the give birth to male genes will then rise up to 50 percent of the population.

https://en.m.wikipedia.org/wiki/Fisher%27s_principle

dabbledash• 6 years ago

If you are a member of a species with 3 females to every 1 male, that means the average male of your species has 3 times as many offspring as the average female.

Under those circumstances, if you have a mutation that causes you to produce all male offspring, you will have many more grandchildren than average.

This pressure will always favor producing whatever sex is in short supply, pushing sex ratios to 50%.

staticman22• 6 years ago

That would be a big disadvantage in terms of evolution (less females means less passing on the species genes) so it seems unlikely.

ajkjk2• 6 years ago

That seems overly simplistic. There are a lot of factors that could affect what the optimal ratio would be.

jtlienwis• 6 years ago

I saw a program once about elephants that showed that they carried around the bones of the revered loved ones in their mouths. Maybe the males were not as revered or maybe they tended to die in spots that it was dangerous to get to carry away their bones.

bkb• 6 years ago

Dudes rock

seph-reed4• 6 years ago

dudes become rocks might be more accurate

openasocket3• 6 years ago

Interesting fact: there’s actually a specific phenomenon in modern-day elephants that explains the idea of males being more reckless. Modern elephant males periodically go through a process called musth . It’s sort of like the male version of going into heat. Their testosterone goes up like 60x and they become aggressive and even violent. They’ll even attack humans and other animals with little warning. A guide at Kruger national park in South Africa mentioned that they once had a spree of young bull elephants going into musth and attacking and breaking the spines of rhinoceros. I imagine if mammoths also went through musth they wouldn’t be particularly cautious about terrain hazards and the like

celrod• 6 years ago

They all died, male and female alike, but a higher percent of the males left behind fossils. Meaning getting yourself killed is only part of the equation. The other part is that the manner in which you get yourself killed has to increase the odds of fossilization. Maybe an elephant in musth chasing rhinos pays less attention to where it's going and accidentally get itself trapped in a tar pit.

trianglem2• 6 years ago

The females probably all died together in a group and are less dispersed so are harder to find. Obvious conjecture.

barkingcat• 6 years ago

Or there are biochemical processes that prefer preservation of male specimens, for example the prehistoric version of male hormones acting as a preservative, or perhaps the prehistoric version of the female horomone acting as a cue for insects or decomposers in the ecosystem to consume the carcass etc.

Gibbon1• 6 years ago

Women probably more likely to die in childbirth or with a group of family members and end up being properly buried. I think most soils aren't conductive to preservation. Thus anyone given proper funeral rites wont end up as a fossil.

dmix• 6 years ago

Mammoths and Mastodons seem like even more dangerous elephants (especially aesthetically with their giant horns). So I wouldn't be surprised they acted similarly.

Maybe that sort of thing played a role in various big game species extinction in many places. They seemed scarier, and/or actually were more aggressive during certain phases like Musking.

pc86• 6 years ago

Is musth correlated with reproduction the way heat is, or is it something else?

openasocket3• 6 years ago

I’m actually not sure. Based on the Wikipedia page, bulls in musth emit a characteristic low-pitched tone that females in heat seem to respond to. And the testosterone levels wouldn’t hurt sperm production. I don’t know much beyond the Wikipedia page and some information I learned from some guides, but it sounds like the exact evolutionary advantage/purpose isn’t well understood. It’s interesting that the females also go into heat. The musth certainly seems like the male analogue of heat. And the male aggression is certainly similar to what you see in some other herd animals during mating season (aka rutting, though I don’t know enough to be able to compare the aggression levels of musth with that of a rutting deer or bison). Elephants in musth will fight other elephants, and unlike normal mating dominance fights they will try to really kill the other. Part of me wonders if this is a part of natural selection. A grown bull elephant doesn’t really have any predators, except another bull elephant in musth.

Another interesting fact about musth is it seems to effect elephant society. When young males reach adulthood and leave the herd of females, they tend to form small “bachelor herds” consisting of a few other young males and an older male, who “shows them the ropes”. And one of the things the older male teaches them is self control during musth. The Wikipedia article, and a story a guide told me, mention that young males in musth without an older male presence to help guide them (teach them?) will be more aggressive.

voldacar• 6 years ago

All creatures die regardless of how reckless they were when they were alive

the question is why males seem to become fossilized more often than females. Uneven distributions of recklessness while alive are irrelevant

contingencies• 6 years ago

Wiktionary etymology: Persian مست‎ (mast, “drunk, inebriated”).

1MachineElf• 6 years ago

Perhaps the connection with the article here is that young bodies fossilize better, and more males died young.

taphangum• 6 years ago

Males took more risk and therefore died in places that would more likely preserve their fossils?

swayvil3• 6 years ago

That's my guess too.

seg_lol• 6 years ago

Not that the places are likely to preserve, but a larger diversity of places.

jccooper• 6 years ago

There's probably some of the former. Many fossilizing environments are more dangerous, and sometimes in surprising ways that more cautious--or experienced--individuals would avoid or approach more carefully. Tar pits, caves and crevasses, river banks, wetlands.

swayvil3• 6 years ago

Men were more likely to die in circumstances conducive to corpse-preservation, or the reverse for women. That's my guess.

At home with the compost vs out on the dusty cementicious steppe.

mkl2• 6 years ago

The article is not about humans or our ancestors.

robotresearcher• 6 years ago

Towards the end of the article they state a second hypothesis that seems to be ignored in these comments but pretty plausible: people kept the larger examples they found, skewing the collections in favor of size, and thus males over females.

Of course, there could be more than one selection effect at work.

jbay808• 6 years ago

How common is it across species that males are larger? It's definitely not universal.

trianglem2• 6 years ago

In mammals it’s near universal I think with the exception of whales where the sizes are comparable.

tachyonbeam2• 6 years ago

AFAIK, animals where there is stronger competition among males for females tend to have more of a size difference. Species that are purely pair bonding tend to have animals of similar sizes. Humans have relatively little size difference compared to other mammalian species. There are many spider species where the male is smaller.

GoblinSlayer• 6 years ago

Females were eaten, because they are weaker. Would like some data on predators.

COGlory• 6 years ago

A dead male and a dead female have roughly proportional strength. And seeing as how there's no wooly mammoths walking around anymore, I'm going to go out on a limb and suggest that all of them died at some point or another

hawktheslayer• 6 years ago

The article mentions they use DNA testing to determine the sex and also that it's tough to find usable DNA samples. Could it be possible that male fossils are more likely to have usable DNA and thus bias the results?

amelius• 6 years ago

Another wild guess: X chromosomes degrading into Y chromosomes over time?

vagrantJin• 6 years ago

That is wild. Too wild. Jesus.

orthoxerox• 6 years ago

Don't dinosaurs have WZ and ZZ, like birds?

MereInterest• 6 years ago

Y chromosomes being male is species-specific, and so that wouldn't generalize across species.

https://en.wikipedia.org/wiki/Sex-determination_system

ksk• 6 years ago

Could it be possible that male fossils are more likely to have usable DNA and thus bias the results?

You can't change the hypothesis to match data. We try to avoid doing that in science ;)

5555624• 6 years ago

From September 2019, when he article was published, https://news.ycombinator.com/item?id=20995396

Paleontologists are trying to understand why the fossil record is mostly males

Related Stories