Why Is the Kiwi's Egg So Big? | Hacker News Reader

Why Is the Kiwi's Egg So Big?

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Kiwis also have a larger brain than other birds their size.

The causes and consequences of this are worth investigating.

A lot of animals have an architecture where they can’t carry a large brain, so a slightly larger brain is more of a hindrance than a help.

Bipedal animals can balance a heavier brain on their upright frame. But flying animals can’t afford too much extra weight.

I’m not sure what they do with the extra brain cells, but I suspect that their specially evolved nostrils would benefit from a powerful processing unit.

(Pigs for example have a large brain both in comparison to their body and in comparison to all other animals. I think the extra processing there is largely to support their incredible proboscis. Eg their legendary truffle hunting skills.)

I think our early human ancestor’s big brain was particularly useful for visual processing to assist with bipedal running/hunting.

Pigs undoubtedly have a better sense of smell than us, but it's unclear if it's really "better" than dogs. Pigs in truffle hunting is a bit of a misconception. Wild boars might be able to find them sometimes, but the best truffle hunters are dogs. In attempts to quantify "sense of smell" pigs ranked lower than mice and way lower than elephants.

So, no, I don't think the large brain is to do with smell. I think it's more to do with them being quite similar to us which is apparent if you ever encountered a pig. What people do to them is horrible and they don't deserve it.

Acknowledging that my own reading of the situation may be flawed, I'd though the situation was that pigs on average are better at sniffing out truffles, but dogs are the better truffle hunters on account of being "good enough" and the fact that dogs, unlike pigs, aren't going to eat half the truffles they find.

No one here seems to have any idea what they are talking about about. 1. You put a ring in the pig nose so it doesn't root and eat the truffles, 2. Dogs have a better sense of smells than pigs by a lot, 3. Big brains don't come from standing upright, whales and dolphins have larger brains, 3. Brain size is important for intelligence, almost always the larger brain the more intelligent, the whole nonsense of body to brain ratio be more important was to make half the human population not feel as bad about having smaller brains. Almost always, more brain == more smart.

Buddy, you have no clue what you're talking about.

That's why I refuse to take blue whales on in chess

> 3. Big brains don't come from standing upright, whales and dolphins have larger brains

That is a terrible "counterexample" to the idea that it's easier to balance a large brain on top of a spinal column than to support it as it sticks out in front of the animal. Whales are aquatic; every part of their body is supported by the water.

Brain size alone isn't a great indicator of performance. See for instance Neanderthal vs. Sapiens.

Is there any indication Neanderthal were less intellectually capable than H. sapiens?

(I'm only vaguely aware of the field, but nothing I've heard has suggested that credibly.)

No, there isn't such evidence.

My comment was mostly based off DNA left by interbreeding between Neanderthal and Sapiens. Modern humans do carry a small but significant share of DNA inherited from our Neanderthal ancestors [1]. My point was that Genes left by these ancestors were heavily filtered by natural selection for brain-related regions.

That being said, loking it up again now, it seems that more recent publications draw more nuanced conclusions [2]. So maybe my knowledge is out of date, and it's time to pick up the books again :)

[1]: https://en.wikipedia.org/wiki/Neanderthal_genetics [2]: https://www.johnhawks.net/p/many-people-have-a-little-neande...

Alex: My pig has no nose.

Anna: How does he smell?

Alex: Terrible.

Today I learned the distinction between the kiwi bird and the kiwifruit https://en.m.wikipedia.org/wiki/Kiwifruit

I had always thought the latter to be a New Zealand fruit that is the source of the name "kiwi".

No, kiwifruit is Chinese. The more you know.

You were right actually. Yes it's Chinese, but it was popularized by New Zealand - hence the name !

The history of agriculture in New Zealand is very interesting - for such a small country, they sure figured out how to do it well and quite often in very innovative ways.

It's also the country that pretty much 'invented' farm raised venison.

There’s a streak of Dutch through the New Zealand demographic, and the Dutch have been famously fabulous farmers in at least some of the places they’ve inhabited.

Netherlands, South Africa, New Zealand, Tasmania and Victoria in Australia, and at least some US states that are famous for agriculture: California, Illinois, Nebraska, Iowa.

yep, we got em here in Nova Scotia, "little dutch farmers", still doing the dutch beard thing, farming with oxen, deap knowledge of traditional farming practice, oh how they can talk, and bend your ear, best pay attention, as if they like you, they will drop a significant observation into an otherwise seemingly pointless ramble, but as they say....you have to catch it get them in Pennsylvania too, though less obviously out of a clasic painting from the 17th century

The Dutch largely arrived here post WW2, we were doing a bunch of agriculture before then, rest assured.

Didn’t the Dutch acquire New York back in 1613?

Here was referring specifically to New Zealand, apologies for confusion :)

I'd give credit to the Hobbits, they were great farmers!

But they suffer from the same inefficiencies as truffle-hunting pigs: they tend to eat all their produce before making it to market.

Weight-conscious NZ human farmers have the advantage there.

I've seen the word "kiwi" used to refer to the fruit in the US, which just seems odd to me, like calling a pineapple a pine. In my part of teh world its a kiwifruit, not a kiwi.

A kiwi is a New Zealander. In fact while they're both named after the bird, the bird is more often called a kiwi bird than just a kiwi.

Yes us Americans just say kiwis instead of kiwifruits. Not too many kiwi birds or New Zealanders in the states so there's not much confusion

UK people also mostly just call it "kiwi" instead of "kiwifruit". Similar lack of kiwi birds but we do have a fair few kiwi people (at least in London.)

American here. I can state authoritatively I've never confused a greenish fruit with an expatriate of a peri-Australian island.

As a New Zealander, it seems like everywhere other than NZ the default is calling it a "kiwi" instead of "kiwifruit"

I think this is more or less correct. Presumably because the need to distinguish between kiwi fruits and New Zealanders is less important in most other places than in NZ.

German here, it's exclusively Kiwi here, never Kiwifrucht (kiwifruit).

I’ve never heard of anyone calling it a kiwi bird, in NZ or anywhere else.

I’ve read somewhere that Kiwis are in the running for being one of the closest genetic descendants / relatives of the T. rex and if they ever get off New Zealand and are relieved of the island dwarfism pressure…

Can’t a billionaire buy a huge island, build a sanctuary, and relieve some kiwis of this pressure? Kids a million years from now will still want to see T-Rexs

Larger than New Zealand?

The two main parts of the country are the 12th and 14th largest islands on the planet: https://en.wikipedia.org/wiki/List_of_islands_by_area

You need a really big island, like North America.

Is NA really an island? I always thought it was a peninsula on the coast of Central America

In that case, it's almost more plausible to count the Panama canal as a strait.

By that measure there's only one continent with a very, very large saltwater lake.

Nonsense.

There's four.

One is icy AF, and another contains 95% of the world's deadly organisms.

I heard a wealthy man is looking to buy Greenland. Maybe it's for the birds?

New Zealand's total land area is about the same as Colorado or Oregon, and the five extant species of Kiwi inhabits a fraction of that.

New Zealand is nowhere near small enough for island dwarfism.

Maybe, although a more correct term is insular dwarfism, whereby populations are supposedly subject if they’re isolated in anyway.

Definitely not my area of expertise though, purely a fun speculation.

Not super knowledgeable either, but I'm thinking that it's simply because it's fairly easy for animals to change size. Like imagine a size constant in your code and you can just update it and everything magically works. So when you have two populations that get cut off with slighly different environments and selection pressures their sizes are likely to diverge.

> I'm thinking that it's simply because it's fairly easy for animals to change size. Like imagine a size constant in your code and you can just update it and everything magically works.

No, the opposite is the case. You can just scale an animal up. But it won't work well; the larger size requires different support structures than the normal size does. Hence, giant humans tend to be in poor health, with circulatory and other problems.

The reason island populations show size changes is that the tiny environment leaves environmental niches open, and animals of the wrong size can radiate into those empty niches without facing competition from animals that are already filling them more effectively. Island dwarfism is common, and so is island gigantism.

Note that New Zealand obviously is small enough for island dwarfism, since it was small enough for island gigantism. The size seems less relevant than the fact that it was isolated by deep ocean.

Moa seemed to contradict this

What about island gigantism? With no large scale predator, you can just grow bigger

Island birds may become flightless, which lifts constraint on maximum mass.

Though that occurs in other contexts as well: Antarctica (hardly small) with penguins, Africa (dittos) and ostriches, Australia (again) with emus, and South America (again) with the rhea.

There are also flightless island birds, such as the Guam Rail, Henderson crake, Inaccessible Island rail, and across multiple islands, the cassowary.

In summary, they thought it was an evolutionary anachronism, a large egg left over from a larger body size because of assumed relationships with larger ratites like Moas. But subsequent genetic and fossil research challenged that.

The article mentions an emerging view it is about "precocity" - larger and better developed babies, and extra yolk being able to provide nutrition to the baby for longer.

Feels like the animal kingdom opposite of the panda--adults weigh upwards of 300 pounds, but baby panda birth weights are just under 1/3 of a pound.

This puts them in approximately the same magnitude of order as kangaroos.

A male Red Kangaroo can weigh upwards of 92kg and stand around the 1.8m (6 feet) mark. Some are over two metres tall. I’ve seen a couple giants, well over two metres and biceps as big as my thigh. Anyways, kangaroo sucklings typically way less than one gram.

Although they are special case of mammal.

Kangaroos are also comically dumb.

The Save the Kiwi trust mentioned on a Kiwi release day that when releasing Kiwis back into the wild there's a weight that the Kiwi must reach (1kg) before having a chance to survive against ferrets, rats, and stoats.

Perhaps the larger egg ensures a reduced exposure time between birth and 1kg for young Kiwis, which has helped those with larger eggs propagate more successfully?

Maybe it's handling the eggs that taught the Kiwis rugby

Why does the Porridge Bird lay its egg in the air?

https://www.youtube.com/watch?v=lmWFrMq3qNY&t=1457s

This led me down a ChatGPT rabbit hole of trying to figure out how long it would take kiwis to convergently evolve into humanoids…

Unrelated, I’m starting a new co called “Super-Kiwi” — time-to-market is ~200-300 million years.

ChatGPT has no clue, you should not have bothered and instead have a read on Wikipedia.

Considering that humans evolved out of what were effectively mice at the end of the Cretaceous (~62M years ago), 200M seems wildly out of proportion. Of course you’d still need the right evolutionary pressure and tweak your definition of humanoid.

> ChatGPT has no clue

Yes, and neither did I!

I simply asked o3 (after learning about kiwis), if, given that our common ancestor was ~300m years old, would it be possible in the same time frame (assuming it would be).

o3 vehemently disagreed:

> Not impossible, <bold>just very, very unlikely.</bold>

I then learned about Dollo’s law of irreversibility[0], and onto stick bugs regrowing wings, etc.

Eventually we got to computational estimates for simulation of evolution, which it then got very defensive about:

>“<bold>Utterly out of reach</bold> today.. ”

My takeaway is that LLMs are a lot more human (thinking in the present), than one might assume an AGI to be.

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