Orca’s also develop “specialization” with different pods developing specific hunting techniques based on the primary type of prey in their locale.

Ah, yes, though that just reinforces the point. Thanks.

The name comes from the fact that Orcas kill other whales. Killing sharks does nothing to reinforce this.

> Sharks have an additional disadvantage over bony fishes, in that they must be moving for their gills to work at all.

The name for this is -"obligate ram ventilators" which is a fantastic phrase.

No. Large differences in brain weight (e.g. factors of 10 or more) can sometimes matter. But weight is just a poor proxy for more important factors: Number of neurons, number of neuronal interconnections, and specialization of brain areas. Within a species, brain weight differences are unimportant. Even between species it's often unimportant. Blue whale brains are 4x as heavy as human brains but the whales have fewer neurons, and most of those neurons are dedicated to audio processing.

https://blogs.scientificamerican.com/news-blog/are-whales-sm...

That effect almost certainly exists, but whether it amounts to anything much at the small relative differences you'd see between members of the same species is much less apparent. And of course, you're sort of implying that this it is absurd to suggest that brain weight explains intelligence; but note that just because there's a correlation between brain mass and intelligence doesn't mean it's the only factor or even major factor. Not that it's trivial to even measure intelligence or that it's even a well-defined concept, but hey.

So before you jump to conclusions: there is obviously research on the matter; e.g. you might start here: https://www.scientificamerican.com/article/does-brain-size-m...

But while the effects in humans may be small, the difference between 35g and 7kg is... huge, so even if the effect might be imperceptible and in any case likely irrelevant between healthy humans, that's another story at that kind of ratio. Not to mention that I'm going to take a wild stab in the dark and conjecture that metabolic differences may even increase that difference (i.e. the orca's brain may be running hotter, too).

it's absolutely true between species, along with how developed particular areas are. Within a species with roughly the same relative size and brain area development it is not the case. The poster didn't imply anything else. Scientists tend to condition it with brain to weight ratio as a close correlation to intelligence. It's easy enough to find on the internet if you're interested.

See also https://en.wikipedia.org/wiki/Pakicetus

The docile hippo - one of the most dangerous animals in the world