Extinct goat was cold-blooded (2009)

https://phys.org/news/2009-11-extinct-goat-cold-blooded.html

by samaysharma • 3 years ago

169 98 3 years ago

phys.org

tardibear• 3 years ago

(2009)

dang3• 3 years ago

Added. Thanks!

Havoc• 3 years ago

Wow - mind blown. I had somehow assumed large creatures can't be cold-blooded

gweinberg• 3 years ago

It's a pygmy goat, it's smaller than a croc or a dragon.

whyenot3• 3 years ago

Are dragons cold blooded? I thought most of them breathed fire.

api• 3 years ago

"Myotragus balearicus" would be a good black metal band name now. The cold-blooded goat.

mistrial9• 3 years ago

"good" LOL

Qem2• 3 years ago

Some days ago there was news about some researchers predicting mammals would be doomed by the next supercontinent cycle, due to too high temperatures incompatible with warm blooded creatures. Well, if mammals can just evolve back cold blood, perhaps that makes their thesis moot. See https://news.ycombinator.com/item?id=37654289

juujian• 3 years ago

Mammals have adapted to adverse conditions before. However, the current rate of change is unprecedented. Evolution does not happen in one or two generations.

fsckboy2• 3 years ago

when evolutions happen, they do happen in one generation, that's where new clades are formed

whyenot3• 3 years ago

A significant number of mammals have generations every year (or less).

Qem2• 3 years ago

The next supercontinent is expected to form in about 250 million years. Plenty of time for mammals to evolve, if we don't wipe all the other first.

edgyquant• 3 years ago

Turning to cold blooded probably doesn’t, but evolution most certainly occurs in a generation. It may mean all but a few who manage to survive die but those are the ancestors of the new species

omeid2• 3 years ago

That argument is only true for humans and other "long" lived species. For example look at at how much canines have evolved in the same time span that homosapiens have stayed relatively "static".

Long and static, in very very relative terms, of course.

dclowd9901• 3 years ago

Does that mean it can’t? I know at least a few people who are especially sensitive to heat and cold. It seems likely there are folks out there who could continue to survive environmental changes given our population, just not as many as currently exist.

jemmyw• 3 years ago

This prediction isn't about climate change, it's about the formation of a new super continent. Because it'll be such a large landmass, and the energy from the sun increases by about 1% every 100 million years, the inner parts of this continent are predicted to be too hot to support most life as we currently know it. Of course, who can really say what will happen / evolve / be there by that time anyway?

jmartrican• 3 years ago

A large asteroid hit the Earth and lead to rapid unprecedented change. Yet here we are.

Zardoz84• 3 years ago

Dinosaurs and Birds don't had any problems with high temperatures.

harpiaharpyja• 3 years ago

If dinosaurs (birds) can be warm-blooded, I guess mammals can be cold-blooded too.

adrian_b2• 3 years ago

They have the same problems as mammals with high temperatures, but at higher temperatures, because their normal internal temperatures are higher than those of mammals.

selimthegrim• 3 years ago

Lindy mammals?

TheBigSalad• 3 years ago

Imagine have a tiny, lazy goat for a pet.

mometsi• 3 years ago

I want a cashmere one to use as a pillow

aaron695• 3 years ago

Tiny is done, a Pygmy is about the same or you have a slightly larger Nigerian Dwarf of miniature.

Goats 'thing' is their energy. (they will still snuggle during post lunch nap time though)

It's hard to know why you'd want a lazy goat, what comes to mind is house training. That might work.

Also these goats (Myotragus balearicus) are not cold-blooded (Not sure where the headline came from) and I wouldn't call them a goat, since they are closer to a mountain goat which I don't call a goat because they are not a Capra.

_a_a_a_2• 3 years ago

The bones of warm-blooded animals show uninterrupted fast growth, while the bones of cold-blooded animals have parallel growth lines showing interrupted growth corresponding to growth cycles, rather like the rings seen in tree trunks. Growth and metabolism rates are adjusted to suit the amount of food available, whereas warm-blooded animals require food to be available continuously. The Myotragus bones showed the same interrupted growth as reptiles.

Or the goat skeletons had regular periods of interrrupted food leading to regular harsh starvations which left patterns on the bones, maybe?

CommitSyn3• 3 years ago

Yes I'm sure the experts didn't think of the first idea to pop into both of our heads when they published their scientific paper in PNAS. https://www.pnas.org/doi/full/10.1073/pnas.0813385106

However I'm more curious how a skeleton eats, can you elaborate?

_a_a_a_2• 3 years ago

Ok, I did what I criticise others for doing, being the armchair critic. Taken on the chin.

As for the goat skeleton, it eats when the goat eats, you know what I was saying.

dang3• 3 years ago

Please make your substantive points without being snarky.

This is in the site guidelines: https://news.ycombinator.com/newsguidelines.html.

Ericson2314• 3 years ago

It became extent only 3,000 years ago?! Can we assemble a genome?!

kristianp• 3 years ago

Just because their bones grew in cycles like reptiles, does that necessarily mean they have to be cold-blooded too?

stubish• 3 years ago

I wondered that too. I wonder if you see similar bone growth patterns in hibernating animals?

fodkodrasz• 3 years ago

Well, debunking the myth that extinct goat was cold blooded will be a great subject for articles in the future!

fsckboy2• 3 years ago

Bears, and some other mammals, hibernate during which their metabolism drops. Any reason to believe this isn't just an exaggeration of that? It just seems really hard to believe actual cold bloodedness could appear like that. Why wouldn't lizards colonize the island instead?

Modified30192• 3 years ago

I would suggest that it's best to think of it as the exact opposite, mammals came from ectothermic ancestors, and gradually began to develop what could be considered "extreme hyper-metabolic states" in comparison, which offered various advantages (denatures the proteins in many microorganisms, allows for consistent physical performance and activity at night when when most of the reptile predators were inactive) at the cost of needing a much higher and constant food/energy intake, and began to spend most of their time in such a state until it became "normal". However many mammals still require the ability to enter significantly lower metabolic states to survive every winter.

A good example is Golden Mantle Ground Squirrels for example, which need to consume enough omega-6 PUFAs (I believe linoleic acid is the primary one involved here, not sure about the others) in order to activate a switch in metabolism that ultimately drops energy use and puts them in a feedback loop to keep them there. [0] They'll periodically have rises in metabolism followed by some activity, and then drop back down into torpor throughout the winter. Squirrels that fail to kick off this change strongly enough are at big risk of burning too much energy and failing to survive the winter. Far less extreme and more well known are bears who also undergo significant fatty acid content changes. [1] Of course, metabolism is hideously complicated, and is effected by things like sunlight (touches vitamin D related pathways, among other things), vitamins (B vitamins are particularly notable) and fatty acids, proteins and carbs which all have have their own individual effects which can change in magnitude or even result in the reverse of what they "should" be doing. Look at this fucking shit and despair of ever trying to make a single correct context independent statement.[2] A perfect example I just found while looking up the other study is that while golden mantle ground squirrels appear to require linoleic acid to enter torpor, this study found that removing linoleic acid 19 days prior to hibernation enhanced how deeply they entered torpor. This isn't surprising to me, because I've heard of the possibility of linoleic acid being potentially exothermic in unusual circumstances, like extreme amounts. So laying off it once the cycle has started may allow the various feedback loops in place when monounsaturated fats run the show to more strongly express [3]

I personally consider all mammals as retaining echos of our cold blooded heritage and capable of enter lower metabolic states, both daily and seasonally (to a widely varying degree) depending on the aforementioned very complex set of conditions. This study seems to agree with me. [4] So I also personally find it quite plausible that if evolution begins selecting against the hypermetabolism that was adopted, then the genetics are still ready and waiting for re-emergence, especially on an island where disease pressure is going to be much more limited. Evolution seems to like adding and repurposing things we already have, adding layers upon layers and rarely ever actually removing things.

As for why lizards wouldn't dominate the island, there were and still are lizards present, unlike the goats who didn't manage to evolve back into lizards fast enough to escape notice by humans and thus extinction (though a quick search seems to show that many lizards on the island are also considered endangered). That said lizards are generally predators/omnivores, whereas the goats are herbivores, so they weren't likely to be strongly competing for the same niche.

[0] "The Influence of Dietary Fatty Acids on Hibernation by Golden-Mantled Ground Squirrels (Spermophilus lateralis)": https://www.journals.uchicago.edu/doi/10.1086/physzool.65.5....

[1] "Lipidomics Reveals Seasonal Shifts in a Large-Bodied Hibernator, the Brown Bear": https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6474398/

[2] Metabolic pathway charts:

- The famous Roche chart: http://biochemical-pathways.com/#/map/1

- Hand assembled map of the above https://faculty.cc.gatech.edu/~turk/bio_sim/articles/metabol...

[3] Short-Term Variations in Diet Fatty Acid Composition and Torpor by Ground Squirrels: https://www.jstor.org/stable/1383506

[4] "Daily torpor and hibernation in birds and mammals": https://onlinelibrary.wiley.com/doi/10.1111/brv.12137

MrBuddyCasino• 3 years ago

PUFAs also drop body temperature in humans, afaik via suppression of the thyroid. Avoid them if you can.

lightedman• 3 years ago

No such thing as hot or cold blooded.

You have:

    Endothermic: Generating internal heat to moderate body temperature, e.g., modern birds and mammals.

    Ectothermic: Relying on the environment and behavior to regulate body temperature, e.g., typical reptiles.

    Homeothermic: Maintaining a constant internal body temperature, e.g., modern mammals, birds, and some others.

    Poikilothermic: Having a fluctuating internal body temperature depending on the local environmental conditions, e.g., typical reptiles and actinopterygiian fish.

mastermojo• 3 years ago

Looking at only what you presented, it seems like Endothermic/Homeothermic share a lot of overlap (hot blooded) and Ectothermic/Poikilothermic share a lot of overlap (cold blooded)?

wiml• 3 years ago

I think endo/ecto are mechanisms and homeo/poikilo are results. They mostly match up (why spend all that energy generating body heat if you're not going to use it to maintain a constant maximally-biochemically-effective temperature?) but not 100%. An ectothermic-homeothermic animal would have to put more effort into using the environment to maintain a constant body temperature. Google says there are some lizards in that category.

TylerE• 3 years ago

I guess the distinction would be that hot and cold are quantitative. There are "cold" blooded reptiles that love temps well in excess of 120 degrees.

qart• 3 years ago

We still have one cold-blooded mammal species around[1]. And a few marine fish species that are partially[2] or fully warm-blooded[3].

[1] https://en.wikipedia.org/wiki/Naked_mole-rat

[2] https://en.wikipedia.org/wiki/Swordfish

[3] https://en.wikipedia.org/wiki/Thunnus

sigmoid10• 3 years ago

Huh. TIL tuna fish are warm blooded.

steve_adams_86• 3 years ago

Bluefins can generate so much heat in their bodies that their muscle fibres denature. Sometimes this happens while stressed on a fishing line, for example.

cyberax• 3 years ago

Some lizards are (somewhat) warm-blooded as well: https://www.science.org/content/article/world-s-first-warm-b...

DoreenMichele• 3 years ago

There are bison on Catalina Island, left there by a film company around a hundred years ago. They are smaller than bison on the mainland:

“They’re very challenged healthwise when they’re on this island because they don’t have the adequate nutrition during the right time of year,” King said. “So, our bison are in fact a little smaller than the mainland, and it’s not a genetic difference. It’s due to not having the right nutrients at the right time.”

https://www.voanews.com/a/history-catalina-bison-hollywood-t...

The article also notes that bison from the island were relocated back to the mainland on three separate occasions to try to reestablish herds here. I can't currently find a citation, but I recall reading that bison that were returned to the mainland put on weight.

It's well established that island populations of animals trend physically smaller. That part isn't at all news.

mkl• 3 years ago

It's well established that island populations of animals trend physically smaller.

Big animals trend smaller (https://en.wikipedia.org/wiki/Insular_dwarfism), and small animals trend bigger (https://en.wikipedia.org/wiki/Island_gigantism). Hence the giant rabbits on Menorca that these goats outcompeted when the islands were connected (https://en.wikipedia.org/wiki/Nuralagus).

londons_explore• 3 years ago

Myotragus survived on the island as dwarf cold-blooded animals for millenia because they had no natural enemies, but they could not survive the predation of humans when they arrived on the island about 3,000 years ago.

One more thing killed by humans.

samus4• 3 years ago

Don't be fooled, animals and other organisms happily extincted each other throughout all the history of life. We just have less data about them.

pugworthy• 3 years ago

Kind of a crossover thing from the blind cooking post, but it's interesting that they have smaller eyes and smaller brains.

Basically, if you assume that vision requires a lot of compute power to process, and that compute power (that is, brains) are major energy users, those with simpler vision processing needs use less energy.

It's kind of a first principles thing I suppose. What uses a lot of energy? Brain. What is the brain doing a lot? Managing vision. Idea? Reduce vision input.

tough• 3 years ago

how does this apply to octopuses having brain-like tissue ina ll it's arms?

adrian_b2• 3 years ago

They have that for the same reason, because they have huge arrays of sensors in their arms and they need to process their output close to the sensors, due to the low speed of propagation of signals through nerves.

An artificial robot does not have these constraints of proximity between sensors and the place where their output is processed, because the delay over electrical wires is negligible at the time scale of most sensor outputs.

samus4• 3 years ago

A big factor is also the lack of predators. To help avoid predators, it helps to have good eyes and the brains to process what you see. If there are no predators, then other factors exert their influence. Large, complex organs consume lots of energy and "harmful" mutations that shrink them will accumulate because the lack of energy on prehistoric Mallorca makes that an advantage.

Groxx• 3 years ago

Huh. Is the evidence mostly bone growth patterns? That certainly seems likely to follow metabolism... but it does make me wonder what the difference is compared to hibernating mammals. (Much) longer periods at each rate? Something else?

RachelF• 3 years ago

Yes, it is a huge jump to assume the were cold blooded, rather than slow growing, or seasonal depending on the plants they ate. There's a lot of mammalian metabolism that stops working at room temperature.

pvaldes• 3 years ago

Very unlikely. needs better proofs

... and they need also to review the concept of fibrocartilage, that shows very similar rings, in animals not suspicious at all of having a reptilian metabolism or cold blood (Like, for example: humans).

The main problem could be trying too hard to milk a poor sample. If this animal was cold blooded, why the other goats and sheep living in bad places didn't developed a similar system? We have lots of sheep races selected for very poor environments. We fully explored their different genetic possibilities... nobody has seen a "crocodile like" sheep in the whole planet

Extinct goat was cold-blooded (2009)

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