Humans diverged from chimpanzees some 5 to 7 million years ago, and access to seaweed may have helped the transition along.
In a study published in the Journal of Applied Phycology, Ole Mouritsen and colleagues showed that nutrients needed by humans' primitive ancestors to cross over and become modern Homo sapiens were present in seaweeds, which were abundantly present along shores. To foragers, a rich coastal environment would be a prime source of crucial nutrients.
Requirements For Evolution
The past 2.5 million years saw the human brain undergo the most significant level of development, resulting in modern-day humans developing an organ that basically defines human qualities. Energy-rich food was already necessary back then for human ancestors to survive, and stepping beyond the line to evolve meant even more nutrients were needed to fuel dramatic brain development.
According to earlier research, nutrients like zinc and magnesium are necessary to modern brains, so much so that brains won't be able to function without them. And because seaweeds provided these crucial nutrients, it is likely that access to the marine plant influenced the human brain to evolve into what it is today.
"Seaweeds of different types ... can be found all across the intertidal zone ... and they could be readily and repeatedly harvested for food by all family members, including women and children," said the researchers.
Human ancestors had access to a host of other food options like fish, snails, crustaceans, and marine vertebrates. However, they didn't have a basic understanding of tidal cycles and similar factors that influence availability, so they didn't always have these types of food to consume. Seaweed, on the other hand, was more widely available regardless of the season.
The marine plant may have contributed to human evolution in the past but its benefits are not lost on people today. Some of the nutrients found in seaweed include:
Taurine - Found in marine fish, red algae, mammal meat, and shellfish, it is present in large amounts in the retina and the central nervous system. The nutrient is present in highest concentrations while the brain is developing, with adults having approximately just a third of what newborns have.
Magnesium - Found in macroalgae, nuts, squash and pumpkin seeds, and legumes, it plays a key role in cognition and neuroprotection, and greatly supports ability to store new information within neural networks.
Zinc - Particularly available in various meat cuts, especially liver, and oysters, crustaceans, and many seaweed types, it has a major role in memory, development, and learning.
Vitamin B12 - While usually available in animal products such as milk, fish, eggs, and meat, it has been confirmed in the seaweed species Pyropia. When consumed, it supports cognitive functions and promotes blood flow within the brain.
Iodine - Found abundantly in brown seaweed, it is a necessary element in thyroid hormone synthesis, which is a crucial component in the development of the central nervous system.
Poly-unsaturated fatty acids - While PUFAs are commonly thought to come from shellfish and fish, they are, in fact, originally sourced from macro- and microalgae like seaweed.