All vegetable oils are liquid at room temperature and are called “polyunsaturated fatty acids.” Fatty acids that are solid at room temperature are called “saturated fatty acids,” and they are found in animal products like Ghee or plant products like Coconut Oil and Palm oil.
There are several other fatty acids that are very difficult to make, but ultimately, in a pinch, human metabolism can construct them using only linoleic acid.
Evolutionary nutritionist Michael Crawford has emphasized the importance of the longer-chained, more complex omega-3 and omega-6 fatty acids in building an intelligent human brain.
He and many other nutritionists propose that their presence in high concentrations in seafoods makes fish a better brain food than meat.
-Sex, Time, and Power - How Womens Sexuality Shaped Human Evolution (Leonard Shlain) (Z-Library)