Age gap. Some scientists believe that within the next few decades, it could be possible for humans to live 1,000 years or more. Normally, as time passes, our cells undergo changes: Our DNA mutates, cells stop dividing, and harmful junk—by-products of cellular activity—builds up.
"Someone could even live to 1,000, but the probability of that is one in 1 quintillion," Milholland added. (If all the humans who have ever lived in the history of the species were totaled up, we'd still fall short of 1 quintillion.)
While the population can expect to live longer lives on average, the human lifespan might have a cap. Scientists believe that the human lifespan could be anywhere from 120-150 years long, but not longer than that, due to accumulating hallmarks of aging and chronic disease.
The current longevity record is held by Jeanne Calment, a French woman who passed away in 1997 at the age of 122 years and five months (see 'The rising age of the longest-living human').
Humans' life expectancy (average) is 70-85 years. However, the oldest verified person (Jeanne Clement, 1875-1997) lived up to 122 years. As a person ages, the telomeres (chromosome ends) tend to become shorter in every consecutive cycle of replication. Also, bones start getting weaker by reducing in size and density.
According to one tradition, Epimenides of Crete (7th, 6th centuries BC) lived nearly 300 years.
By 2050, we could all be living to 120, but how? As hard as it is to believe, just 150 years ago the average lifespan was 40 years. Yes, what we'd consider mid-life today was a full innings for our great-great-grandparents.
Normally, as time passes, our cells undergo changes: Our DNA mutates, cells stop dividing, and harmful junk—by-products of cellular activity—builds up. All these processes together cause us to age.
Plus, there will be an increase in both the average height and longevity of most people in general. That means, in the year 3000 people will be about six feet tall and live to be 120 years old, on average. They will also tend to experience a slight reduction in the size of their mouths, as well.
The oldest known living person is Lucile Randon of France, aged 118 years, 334 days. The oldest known living man is Juan Vicente Pérez Mora, of Venezuela, aged 113 years, 229 days. The 100 oldest women have, on average, lived several years longer than the 100 oldest men.
By preventing cells from reaching senescence one can achieve biological immortality; telomeres, a "cap" at the end of DNA, are thought to be the cause of cell aging. Every time a cell divides the telomere becomes a bit shorter; when it is finally worn down, the cell is unable to split and dies.
Your cells are programmed to divide, multiply, and perform basic biological functions. But the more cells divide, the older they get. In turn, cells eventually lose their ability to function properly. Cellular damage also increases as cells get older.
The increased longevity of humans is, in part, attributable to environmental changes; improved food, water, and hygiene; reduced impact of infectious disease; and improved medical care at all ages.
Scientists have found a way to lengthen worms' lives so much, if the process works in humans, we might all soon be living for 500 years. They've discovered a "double mutant" technique, when applied to nematode worms, makes them live five times longer than usual.
The skull will get bigger but the brain will get smaller
Humans in the year 3000 will have a larger skull but, at the same time, a very small brain. "It's possible that we will develop thicker skulls, but if a scientific theory is to be believed, technology can also change the size of our brains," they write.
First and foremost is that while Paleolithic-era humans may have been fit and trim, their average life expectancy was in the neighborhood of 35 years. The standard response to this is that average life expectancy fluctuated throughout history, and after the advent of farming was sometimes even lower than 35.
According to the company, humans in the year 3000 could have a hunched back, wide neck, clawed hand from texting and a second set of eyelids.
For most of human history, life expectancy has been short - perhaps 25 years for our hunter-gatherer ancestors and only 37 years for residents of England in 1700.
To date, there's only one species that has been called 'biologically immortal': the jellyfish Turritopsis dohrnii. These small, transparent animals hang out in oceans around the world and can turn back time by reverting to an earlier stage of their life cycle.
During death, your body's vital functions stop entirely. Your heart no longer beats, your breath stops and your brain stops functioning. Studies suggest that brain activity may continue several minutes after a person has been declared dead. Still, brain activity isn't the same as consciousness or awareness.
In the climate of 2100, there will be plenty of environments between these current extremes. Hence, it is safe to conclude that Earth will be habitable.
Our estimates suggest that about 300,000 people will reach age 110 by 2080, give or take about 100,000. Although this range is well below a million, it makes the one-in-a-million chance that at least one of them will reach age 130 a real possibility.
It is estimated that there will be about 10 to 20 million centenarians alive in 2100. Given mortality rates at 100 years of about 50% per year this means that 5 to 10 million will survive from the year 2000 cohort. Therefore the chances of survival are very roughly 5% or one in 20.