ONE of my colleagues told me how, as a child, he was horrified by the realization that his dear mom and dad would one day die, leaving him to fend for himself.

He was so horrified at this idea that he was thrown into a state of panic.

When we embark upon the journey of life, few realize that we have a destination. At times, we may even find the journey tediously long. Others reach their destination abruptly, not yet fully prepared. But most travelers are warned repeatedly of the terminal as it approaches.

Take the colleague again. Now near his retirement, he looks much younger than his actual age. Having avoided the paunch typical of men at his age, he certainly ages well.

But obviously he has not eluded ageing itself, which has shown itself in other ways. Not long ago he told me with dismay that he could not believe how wrinkled the skin on the back of his palms had become.

As we age, we get used to the many slings and arrows outrageous fortune has in store for us. “Old age ain’t no place for sissies,” said actress Bette Davis. As cited at the beginning of “How Men Age: What Evolution Reveals about Male Health and Mortality” by Richard G. Bribiescas, many of the changes we experience are natural human adjustments to the ageing process.

Virtually all physical traits associated with aging are a compromise in response to development and needs of other traits, or what the author calls “trade-offs.”

“Trade-offs are a primary driver of aging. Men and women contend with different trade-offs and therefore exhibit different patterns of aging and death,” Bribiescas writes.

Men tend to lose muscle mass and gain fat as they age. Reproduction is, of course, central to our ageing, since selection favors organisms that reproduce effectively at higher rates, which is energy- and time-consuming. “A male body needs to make crucial decisions about how to allocate calories and other resources to promote reproductive success,” the author argues.

In Darwinian evolutionary theory, surviving is meaningless if it does not serve reproduction — hence Bribiescas’ conclusion that males may have developed “unique solutions to maintain the ability to father offspring at older ages and address the challenge of somatic degradation and aging.”

Does this explain the discrepancy in life expectancy for males and females? Maybe, to a certain degree, as this can also be a trade-off. But evolution seems to account more cogently for the emergence and spread of obesity, in terms of our propensity to sequester too much energy from environments that are awash in quick, abundant, and easily accessed calories.

It is also observed that many male-specific diseases are the result of processes that have beneficial effects early in life, but come with downstream costs. For example, higher testosterone levels during early adulthood, when reproduction typically occurs, promote and support greater libido and muscle mass. However, the cumulative effects of a lifetime of exposure to testosterone can contribute to prostrate hyperplasia and cancer later in life.

Social factors

In other words, natural selection accounts for traits that in the end result in greater reproductive fitness, not necessarily health. But there is a limit to what evolution can explain, as no other organism exhibits the level of cultural complexity as humans.

As a result of this complexity, human beings have developed unique and often illogical social practices. They do things that seem to contradict the premises laid out by evolutionists. Generally we are not aware of our mortality, or vulnerability, until after a certain age.

“It may help to think of life span as the fuel gauge in your car. Many things such as road hazards, traffic, imperfections in the car’s engine, detours, and weather conditions will influence how you expend that fuel and how you plan your journey. But there is one catch. You cannot refuel,” the author observes.

This awareness probably sets us apart from other species. It is observed that small mammals tend to have accelerated aging and shorter lives compared to larger mammals, a phenomenon generally attributed to the need for smaller organisms to maintain faster metabolic rates to keep up with loss in heat.

Smaller mammals burn out faster due to their relative larger surface area, though this fails to explain the relative longevity of women, who are generally smaller in size.

Demographic analysis finds that for humans, regardless of environment, mortality starts to increase around the age of fifty but spikes after sixty-five.

“After the age of sixty, the mortality gap between men and women widens, with men dying of age-associated illness at a much higher rate than women. Interestingly, and tragically, suicide rates in older men also jump in many societies,” Bribiescas points out.

There are many reasons for this discrepancy. For example, male mortality tends to be high because men tend to do a lot of stupid things compared with their female counterparts. Evolutionists argue that men seem to behave at cues from their female counterparts, and data indicate that women prefer men who exhibit a hormonal milieu that is reflective of risky behavior.

However we account for such differences, Bribiescas’ pioneering work does reveal how many physical and behavioral changes that were negatively linked with males may have actually facilitated the emergence of traits that have helped make humans so successful as a species. But males and females probably are equally foolish in their relentless pursuit of immortality, often at the expense of considerable environmental and financial costs, and in spite of the many religious and spiritual teachings designed to alleviate our fear of the hereafter.

Care for the aged also weighs heavily on our own mortality — depending on the number and gender of one’s offspring. “Interesting research … has shown that paternal life span is significantly increased by the presence of more daughters, suggesting that they made significant contributions to the care of their elderly fathers,” the author writes. Revealingly, the number of sons has no effect on paternal life span, presumably since sons are away finding their own fortunes while daughters tended to stay close to home.

The ageing of men is linked with changes in hormone levels, particularly declines in testosterone, lower metabolic rates, and shifts in other areas of the hypothalamic-pituitary-testicular hormones axis. But even these factors have to work in tandem with social support.

A study in Japan found that men with supportive and caring family members likely had better access to health care, which has been shown to promote higher testosterone levels with age. There are still uncertainties over the effect of testosterone supplementation, though the book certainly enriches our understanding of male health and well-being.