Savannah hypothesis

They became savannah dwellers.

And this is where the savannah hypothesis begins.

The idea is elegant and on the surface makes perfect sense.

Those hominids who ventured onto the grasslands faced challenges their forest ancestors never had to deal with.

But in hot environments, that same insulation traps heat from the sun, preventing your body from cooling down efficiently.

It's like wearing a winter coat in the desert.

your ancestors were now walking long distances in intense heat with bodies that generated significant metabolic heat from all that activity and they were wearing fur coats something had to give according to the savannah hypothesis what gave was the fur The theory suggests that as hominids spent more time on the savannah, natural selection began favouring individuals with less fur.

Those with thinner hair coats could cool down more efficiently.

Something significant had to happen to make hairlessness more advantageous than keeping our fur.

And for decades, the most popular explanation has been what scientists call the savanna hypothesis.

The story goes like this.

Between six and seven million years ago, our ancestors were living comfortable lives in the forests of Africa.

So the sequence probably went like this: savanna adaptation, then bipedalism, then gradual hair loss combined with increased sweating capacity, then darker skin pigmentation to protect newly exposed skin from sun damage.

Each adaptation building on the previous ones, creating a complete package optimized for surviving in open, hot environments.

But as compelling as the savanna hypothesis sounds, it's not without problems.

The biggest criticism is that the timeline doesn't quite match up.