
Why Whales, the largest animals on Earth, got so big - JumpCrisscross
http://www.latimes.com/science/sciencenow/la-sci-sn-whale-evolution-20170523-story.html
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theprop
We're lucky to be living in amazing times where the largest creatures that
have ever lived on this planet are alive...and their explosion is size is just
3 million years old.

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interfixus
Which must obviously raise the question: Is the coincidence a coincidence?
Which it might well be, but how infinitely more exciting if the giants and we
were somehow molded from the same set of circumstances. I am not really
qualified to judge whether the article implies such a thing.

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Yizahi
I imagine we would have a giant fin along our spine and would be required to
sleep in the sun for 10 hours per day and 8 hours per night to be able to
function in the rest 6 hours. But on the other hand we would be much smarter
with bigger brain in those 6 hours.

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accountyaccount
>"You have the privilege of sharing the planet with the largest animal that
ever lived on Earth."

We've returned the favor by killing 90% of them.

>The IUCN estimates that there are probably between 10,000 and 25,000 blue
whales worldwide today. Before whaling, the largest population was in the
Antarctic, numbering approximately 239,000 (range 202,000 to 311,000).

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jngreenlee
Interesting level of precision used there...Nassim Taleb would hate it. Whom
was whale counting back then?

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accountyaccount
It's based on the number of whales killed by whalers

[http://onlinelibrary.wiley.com/doi/10.1111/j.1748-7692.2004....](http://onlinelibrary.wiley.com/doi/10.1111/j.1748-7692.2004.tb01190.x/abstract;jsessionid=EC6D0DEF83EF0D2B730532B3648DF100.f04t03)

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LeifCarrotson
> Pre-exploitation population estimate of 239,000 (95% interval
> 202,000–311,000).

> Estimated 1996 population size, 1,700 (860–2,900)

Don't use three significant figures when your confidence interval spans 50% of
your estimate. "200,000 to 300,000" would more clearly express the data.

And be honest about accuracy: if modern satellite, aircraft, and naval
technology can't pin the 1996 value down more tightly than "half this number
to double it", you can hardly say with a straight face that your confidence
interval on the 1800s data is "minus 15% to plus 25%".

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accountyaccount
Sometimes shitty data is all you've got — I was making a simple point, not
submitting a paper to a journal.

Humans killed these things by the tens to hundreds of thousands and the
population is no where near that today.

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LeifCarrotson
Sorry, I was commenting on the numbers in the paper and not on your simple
point, with which I agree

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accountyaccount
No worries. Thanks for being cordial. It's easy to get frustrated when
conversations turn this way online.

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jasonsync
Happening with humans too.

Humankind has transformed in the last century-and-a-half: a good chunk of our
species is now taller than it's ever been.

Over the last 150 years the average human height has gone up in industrialized
countries by up to 10 centimetres. And gains of up to 19 centimetres for Dutch
men and woman.

Primarily due to improved nutrition, health, and in general a better quality
of life. [http://www.bbc.com/future/story/20150513-will-humans-keep-
ge...](http://www.bbc.com/future/story/20150513-will-humans-keep-getting-
taller)

~~~
LeifCarrotson
> And gains of up to 19 centimetres for Dutch men and women.

I am a 6' Netherlander (among the shortest men in my family). I just traveled
to Shanghai and met a lot of very short Chinese people - but I was surprised
to see that there seemed to be a small population of some young men who were
as tall or taller than me.

When I asked about these tall Chinese of a native, she explained that they
were from northern China, and that they have a harsher climate and eat more
fish and protein than locals. Many of the locals grew up subsistence farming
under Mao, mostly eating rice, and she explained that the weak nutrition of
the resulting diet resulted in less growth.

This is, of course, anecdotal. But in comparison to Dutch height gain, I
haven't heard of a similar change in Dutch nutrition or health, at least not
relative to peer countries.

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Declanomous
For a large part of history human height has been limited by nutrition. This
is why the United States was the tallest country in the world at the beginning
of the 20th century.

Once everyone is everyone is fed the genetic differences become apparent.

There are plenty examples of this. For instance, the Normans who invaded
England were nearly six feet tall. However, by the mid-17th century the
average man in Europe was something like 5'3-5'6.

My great-grandfather was 5'3, and my great-grandmother was 4'11\. They grew up
during a famine in Hungary. My grandmother was 5'8, my dad was 5'11", and I'm
6'3".

Of course my mom is half dutch, and her mom was 100% dutch and was 6'1", which
is huge considering she was born in 1913. So I definitely get some of my
height from that side of my family.

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metastart
"You have the privilege of sharing the planet with the largest animal that
ever lived on Earth."

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cultofmetatron
correction: largest known animal.

There could very well have been something bigger but never left fossils. I
mean fossil creation itself is sort of a miracle. Combined with such an animal
really bound to living in the ocean, it would be very difficult for a whale
the size of a blue whale to

1: meet the conditions to be fossillized 2: survive millions of years 3:
discovered at the bottom of the ocean

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interfixus
Exactly. These unfounded absolutes are a sloppy habit, though many of us
probably do them from time to time.

Strangely, yesterday I was angrily downvoted for pointing out the same problem
with a historical statement ("the world's first paint").

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nikofeyn
it's not unfounded. there's direct supporting evidence. and they're not really
absolute. it's blatantly obvious that the "that we know about" is implicit.

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malandrew
It seems like humans could also cause them to be bigger. Food distribution
became more concentrated over time. If humans impact the world in a way that
magnifies this power law distribution of food, we could end up with even
bigger whales, right?

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wizardforhire
The reciprocal of this is that here in Oklahoma we've got animal breeders
turning saltwater runoff from reinjection wells into mini seas so as they
claim... to breed tiny pet whales. The goal is to have teacup size whales that
fit into purses in a hundred years or so. Idk internet cuteness combined with
the desire to eat them in a sustained way or something, I guess. I think the
whole thing is crazy and unethical.

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cm2012
There's no such thing as real hundred year business plans.

~~~
kuschku
Or so you claim. There’s enough family business in Europe or Japan that
existed for centuries or even a thousand years that for them a hundred year
business plan can make sense.

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ekianjo
longevity has nothIng to do with havinv hundred years plans. Most businesses
hardly a vision beyond 20 years from now, because the longer you try to
project the more preposterous your assumptions are.

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fiftyacorn
I watched a program once that said that one of the reasons they are so big is
to allow them to communicate over large distances. Is there any truth in that?
It was a kids program though - probably octonauts

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dredmorbius
A problem with any such rationalisation is that evolution is not teleological.

Animals don't _seek_ to become anything, evolutionarily. But characteristics
and traits offer fitness advantages over alternatives.

It's also difficult to disambiguate primary vs. secondary effects and
consequences.

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emiliobumachar
Gp's claim does not imply teleology of any kind; it's entirely plausible in
terms of increasingly larger animals being selected for their hability to
communicate over increasingly larger distances. Finding mates in a larger
volume of ocean comes to mind.

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dredmorbius
It has causality backwards. Teleology itself is ... complicated. It likes it
that way.

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YeGoblynQueenne
So the blue whale got big to eat more krill- does that mean that there's no
other animal than the blue whale that can eat as much krill as a blue whale?

In that case, what would happen to the krill if the blue whale went extinct?
Would its numbers grow uncontrolled until it took over the oceans? Or is other
predation enough to keep its numbers down?

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candiodari
What is not mentioned in the article is the reason big animals exist:
efficiency. The physics are simple: assume animals are ball-shaped (true to
within a factor 2 for mammals). That means the amount of filling grows with
the third power of the radius. The "skin", or outer boundary only grows with
the second power.

"Skin" is how an animal loses power (by far the biggest power draw inside
mammals is keeping the body warm. Obviously in water this is an even bigger
problem). "Filling" is how an animal generates power.

That means that smaller animals cannot hope to match the whales in efficiency:
for sustaining the same biomass, they need to keep a bigger "skin" warm (add
all the skin of all individuals together).

Now when does this matter ? Obviously this would matter a lot in terms of
scarcity, at which point it would be much easier for whales to survive than
smaller fish. When there is richness of food, smaller is better, as you can
move faster and "eat" the available energy faster. However if smaller animals
do this to the point that food becomes scarce, they've just screwed
themselves.

So you see what happens : the longer the biosphere goes without a major
disaster, the bigger animals get (and plants, for that matter). The advantage
of being the first mover, where you can be small and still win, disappears,
and the advantage of efficiency grows and grows. So when food became scarce,
whales, the biggest animals that had the easiest time surviving at that point,
became even bigger. That made the difference between different whale species.

This framework allows answering your question: no, if whales went extinct fish
would increase in numbers (slightly, in the sense that it'd be less than the
biomass of the whales that disappeared). There isn't enough predation to
replace the whales at the moment, but that would be very quickly rectified if
something happened to them.

The real reason krill is increasing is the slight increase of co2 caused by
humans (krill eat plankton, as do most whales). It's tiny when measured
compared to total volume, but if you look at it in relative terms co2 has
increased quite a bit (amount now vs amount 100 years ago). In reality the
plant growth in the world is hampered significantly by the amount of available
co2, and the fact that plants use it to store energy, a part of which gets
buried and is lost to the depths (literally in the case of krill).

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lordnacho
Why doesn't more food simply lead to a higher birth rate? And also what was
the reflexive effect, bigger whales -> more food eaten?

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karthickgururaj
The critical part is not more food, but very unequal distribution of food.
Quoting: "..from the time of the dinosaurs to about 3 million years ago,
nutrients were evenly distributed across the ocean. But then there was a
transition, in which dense aggregations of nutrients could be found along
certain coastlines, while vast parts of the open ocean became virtual marine
deserts."

I guess larger organisms are more likely to survive in this scenario. Maybe
similar to the reasons why larger vehicles are more efficient for
transportation: [http://www.sustainablefreight.com.au/case-studies/bigger-
is-...](http://www.sustainablefreight.com.au/case-studies/bigger-is-better)

~~~
hueving
The whale is the sahuaro cactus of the ocean. :)

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jlebrech
also whales (aquatic animals) are not weighed down by gravity so much, and
that combine with being a mammal must play a part.

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theprop
The ocean and the diversity of life in it is immense and needs to be explored
a lot more.

~~~
659087
I think we've decided to solve that problem by driving most of that life to
extinction. This will eventually make it easier to explore all of it.

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dmd
> Hungry whales accelerate into this swarm with their enormous mouths open,
> eventually filtering out the water and swallowing the krill. Using this
> technique, the biggest whales can ingest half a million calories in a single
> bite.

Also known as a "bloomin' onion".

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nradam123
How many of y'all know that Crocodiles can grow really big because they get
bigger throughout their life? And that crocodiles will not die "unless" they
are deprived of food or get sick? Both true facts.

~~~
colordrops
[https://www.earthtouchnews.com/natural-world/natural-
world/n...](https://www.earthtouchnews.com/natural-world/natural-world/no-
crocodiles-are-not-immortal/)

