The average human life expectancy varies by country and region, but it is not necessarily limited to 100 years. the global average life expectancy was around 73 years. However, in some developed countries, life expectancy could reach the mid-to-late 70s or even 80s. Advances in medicine and healthcare, improvements in living conditions, and better access to nutrition have contributed to longer life expectancies over the years.
That said, there are several biological and environmental factors that can influence human lifespan:
Cellular aging: As we age, our cells and tissues undergo wear and tear. This process is influenced by genetic factors, lifestyle choices, and exposure to various stressors. Over time, this cellular damage accumulates, leading to aging and increased vulnerability to diseases.
Disease and illness: While modern medicine has made significant strides in treating and managing diseases, there are still many health conditions that can be life-threatening, especially in old age. Heart disease, cancer, stroke, and neurodegenerative disorders are some examples.
Genetics: Genetics plays a role in determining a person's susceptibility to certain diseases and their overall longevity. If someone has a family history of long life spans, they may have a higher chance of living longer themselves.
Environmental factors: Living conditions and access to healthcare can significantly impact life expectancy. In areas with better sanitation, nutrition, and healthcare, people tend to live longer.
Evolutionary perspective: From an evolutionary standpoint, there is a trade-off between longevity and reproductive success. Natural selection primarily acts to optimize reproductive fitness, which means that there may not have been strong evolutionary pressure for humans to live much beyond their reproductive years.
It's essential to note that while there is a biological limit to the human lifespan, advancements in medical science and technology could potentially push that limit in the future. Research in areas like regenerative medicine, genetic engineering, and anti-aging therapies may have the potential to extend human life further. However, it's challenging to predict how much longer human lifespans could become in the future.