As for Polynesians (Pineapples) - well they are only 'big & fat' NOW because they pig out on Maccas, etc.
Before that - their physiology of going long distances over long periods between islands provided them with the ability to last longer than other peoples.
Example: (taken from 'In the Heart of the Sea' book, that inspired Moby Dick) - In a life raft for 93 days, the various attributes of different races came into being. It was said that the 'Negro' Whalers were the first to die of starvation because of the very minimal fat content in their system. Then, the White men would die and the Polynesians would last the longest - because they were used to it over a period of 800 years.
Now though, their 'physical' adaption now 'bites them in the big bum' with junk food.
Neanderthal 'genes' also provide the extra retention of 'fat', but people in the modern world of 'junk food' that have the Neanderthal gene - now put on more weight easier than others.
The 'coincidence' of x3 off-shoot races (Neanderthal, Denisovian & 'mystery X') sort of represented Europe, Asia & Africa (just like Britain, Japan & Madagascar were ...'detached'.

The San Bushman contain the 'most and oldest' genes passed down through they ages - yep, genetically, they've been around and amongst all the 'Ancient' races - long before a 'branch' went walkabout into Australia.
The 'youngest' Gene Pools are the Europeans (Non-Neanderthal) and Asians (Non-Denisovians).
Polynesian Pineapples come from Asia and you can see the racial & cultural similarities with the Anu of Japan (Nippon) and the Borneans of (Indonesia).
The Melanesian 'Coconuts' have been around far longer than the Polynesians even farted out of Asia - out towards the 'far pacific' of Oceania.
The Melanesians mostly stuck in the region of Sahul, around the outskirts of the more older Aboriginals that were based in Australia.
It is said that the Aboriginals are very closely related to 'Caucasians' too - genetically linked to the 'Caucasus Mountain' area when they started their migration east through India. Hence the 'caucasoid' WAVY HAIR, rather than the Curly or Straight fibres of Negroid/Melanesian and Mongoloid.
In essence though - the success of the Homo Sapiens was due to both their genetic variety and cultural versatility.
Yep - the most successful race was the MONGREL, not the Pure-Blood.