Humans: are we still evolving?
One of the most enduring questions if biology is whether human beings are still evolving. Darwin taught us that we got here because of evolution. Millions of years of slow, gradual change that turned us into human beings from simple cells.
But are we still evolving?
Because change is so slow, it is hard to understand evolution in one or even a few lifetimes. To understand it, we turn to something known as the caspase gene.
The caspase gene is one of the quiet architects of life and death within the human body. Caspase are not destroyers in the dramatic sense. They are precision instruments. They decide which cells must be removed so that the larger system can survive, adapt and evolve.
Every second, millions of your cells are choosing whether to repair themselves or to die.
Caspase activity is the last sentence in that decision.
What makes caspase so fascinating is that they are ancient. Versions of these genes exist in creatures that lived hundreds of millions of years ago. Long before humans learned to think, caspases were already shaping bodies through controlled cellular death.
This process, called apoptosis, is not decay. It is cleaning up.
Fingers separate in the womb because caspases dissolve the tissue between them. The immune system learns discipline because faulty immune cells are erased by caspase signaling.
Without this gene family, complex life would collapse into biological chaos.
There is a popular idea that modern humans have somehow deactivated the caspase gene as part of our evolution. But the truth is that we have learned to regulate them more tightly.
Compared to earlier organisms, human caspase pathways are layered with checks, balances and feedback loops. This allows longer lifespans, slower tissue turnover and greater neurological stability.
We evolved but at a cost.
In rare cases, specific caspase related genes do become silenced through mutation in certain tissues. When this happens, we get cancer. Cancer survives by blocking caspase activation so that damaged cells refuse to die.
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