Is The Further Evolution of the Human Brain Possible?

Lately, I’ve been hearing some unsettling ideas from various philosophers of science – that’s the term, right? – who cast doubt on the future evolution of our human species, especially in terms of intelligence. According to Herculano-Houzel (2011), the brain already runs on a remarkably tight, fixed energy budget per neuron, which is exactly why any further increase in brain size runs into steep metabolic costs.

Simon Laughlin, a neurobiology professor at the University of Cambridge, suggests that further brain growth would demand so much energy that it could harm our overall efficiency. At first glance, his argument seems sound, but I’ve got a few counterpoints:

• Does bigger always mean better? We all know about Einstein’s brain, which wasn’t larger than average. Yet, it was extraordinary. According to Witelson, Kigar and Harvey (1999), Einstein’s brain was not larger than average, but it had an unusually wide parietal region, a difference in structure rather than size. Women have smaller brains that work just as well as men’s. It’s about how you shape and utilize it, which nature must have its reasons for.
• The quality of thought isn’t just about brain connections, but their quality. An alternative high IQ definition is low “noise.” Neurons have their own activity, and how they react to stimuli varies. It’s a nervous system trait, independent of brain size.
• Energy intake is more flexible today. No need to hunt for every meal; obesity’s the issue. High-calorie food production is easier and cheaper. So, energy concerns for the brain might be overstated.

What Role Do Glial Cells Play?

• Glial cells’ role isn’t fully understood. They nurture neurons and impact intelligence. According to Barres (2008), glial cells are far more active participants in brain function than once assumed, powerfully shaping synapse formation and neuronal signaling rather than merely supporting neurons. But researchers often focus solely on neuron networks, neglecting other message quality influencers.
• I recall a late 19th-century article where Britons believed all inventions were done. That skepticism lingers; claims that “things won’t improve” trigger an allergic reaction. Change is possible.

The real question is whether nature has a reason for making us smarter. Traits that enhance offspring matter. Strength and smarts used to matter; today, it’s a blend of beauty, money, and humor. 

Evolution won’t be as rapid. Birth control in developed countries means fewer births, possibly leading intelligence to diminish. Some say advances in medicine and care let weaker individuals thrive, causing genetic issues and human decline.

According to Byars, Ewbank, Govindaraju and Stearns (2010), natural selection is still measurably acting on contemporary human populations. So the idea that modern life has simply switched evolution off does not hold up.

It’s uncertain, but I believe it’ll get better. I’ll see to it.