Exploring Sikhi ji
Evolutionary biology and evolutionary psychology do not go had in hand.
From the point of view of established scientific method evolutionary psychology still has a long way to go to gain acceptance as science, rather than a collection of conjectures that are then "demonstrated," using samples that are neither representative of the populations they purport to represent nor of sufficient size to allow for statistical evaluations of their accuracy/lack of statistical bias.
Evolutionary psychology fails on the scientific principle of replication because individual studies are difficult to reproduce. Even when findings may be valid for Nottinghamshire, they may not be reproducible in London. Therefore generalizing to the whole of human nature based on descriptive studies conducted with volunteer college students is shaky inference.
Evolutionary psychology in addition fails on the scientific principle of falsification because it has not to date conducted studies that control for other variables that might dispute its starting assumptions, or starting assumptions of any particular study.
Then there is always a problem arguing that principles that guide biological change are the same principles that govern behavior, values, beliefs and emotions. The theoretical arguments abound and have been contested since the middle of the 19 Century. Where are the empirical studies?
Evolutionary psychology suffers from a one-size-fits all fallacy. Men are like xxxxxx because survival depends on it. Men who do not display xxxxxxxx do not have opportunities to attract mates and further their genetic line. This reasoning is out of sync with evolutionary biology. Nature always makes room for the long-shots. The long shots make important contributions to the gene-pool, which is why biological diversity is so important.
Biological structures change/evolve in accordance with the distribution of variant forms within a species. Dominant members of a group may not be able to withstand sudden environmental pressure or change. Deviant members of a species with statistically rare traits can then contribute in stressful periods to long-term survival of the species. This is the fundamental mechanism of natural selection. Natural selection is a long-standing principle of evolutionary biology. It asserts that when a sufficient number of males and females within any species are sufficiently diverse, some deviant members may be better able to withstand environmental change. Because of this, the species will continue. Deviant members may even in time become dominant. Less robust members do not die out, but are simply represented in fewer numbers. Champions that are no longer able to withstand the stress become the new deviants, and a new norm emerges. It is almost as if biology takes out an insurance policy on species survival -- there are always some deviants in the group that may prove to be the champions when the environment shifts enough to threaten a species.
Akasha ji was making somewhat of that argument in layman's terms - albeit the video was melodramatic.
There is always a hint of survival of the fittest throughout the work of evolutionary psychology, Survival of the fittest is not a biological principle but an economic one, coined by Malthus. They have a long way to go.