zoology biology benno meyer rochow science blog death halloween Florian Nock

Science & Halloween : Death

An inevitable part of life’s programme

Only the most primitive organisms, the so-called single cell “animals”, i.e., the protozoans -and not even all of them- are potentially without death as they grow, divide, separate and repeat this cycle over and over again. Normal cells of mammalian tissues in isolated cultures will also continue to “live” and divide, sometimes long after the host’s body they originated from has succumbed. The difference to the protozoan life forms, however, is that these mammalian cells eventually appear to run out of divisions. It is as if death was programmed into their genetic code through the gradual shortening of so-called telomeres present at the ends of the chromosomes. Human cells can divide, and divide, and divide again, perhaps fifty times or a little more, and then they come to the end of the road, so-to-speak. Although human skin cells will be viable for up to a couple of days after a person has died, the often heard opinion that fingernails and body hair continue to grow after death is an illusion brought about by the fact that a dead body loses water and actually shrinks. Thus, the harder structures like fingernails and hair become more prominent and appear to grow.

For many animal species sex is a once in the lifetime experience, heralding death. Once the procreation of the species is guaranteed, there is no real need for the parents. i.e. adult individuals, to continue to be around – in fact, it could be outright detrimental and counterproductive to the survival of the young if, for example, the two generations competed for the same food or, worse still, predatory adults would be unable to recognize their own kin and regard them as prey.

The described situation, in which the adults ‘give way’ to their offspring through dying off holds true for the salmon as well as the eel, the praying mantis as well as the spiders in the cellar or in the garden and many more species of animals. In the octopus there is even a kind of a “death gland” present, located behind the eyes. First, this gland produces a hormone that is responsible for inducing reproduction, but once the female octopus has laid her thousands of little eggs, the countdown begins: the female has little more than a month to live during which she guards and cleans her eggs and loses her appetite. The male is somewhat hardier and lives a little longer. Within a week or so after the baby octopuses hatch, the female dies. But not of starvation or exhaustion, for if the death gland behind the eyes is surgically removed, she continues to live – and because she is hungry she then feasts on her own young!

However, the fact is that the genes of an individual are not gone or lost with an individual’s death. They do not disappear (unless an entire species vanishes): the genes are still present in the offspring and in various combinations also in all those other individuals of the species. Taking that view, one does not have to believe in an afterlife or reincarnation for then even higher animals are potentially without death -unless, of course, like I pointed out above, the whole species dies out.

zoology-suicide death biology benno meyer rochow florian nock

Suicides, the most unique behaviour of all

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2017.
Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s