Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Old age, death and evolution

A hypothesis of the evolutionary origin of ageing has been suggested by A.V. Makrushin, specialist of the I.D. Papanin Institute of Biology of Inland Waters (Russian Academy of Sciences) and published in the Progress of Gerontology journal (2006, issue 19). According to this hypothesis, Metazoa animals had initially possessed physical immortality, but lost this property in the course of evolution.

The first Metazoa animals possessed a modular structure, consisting of several identical individuals combined into a colony. The colony appeared due to gemmation, where sponges grow out of the body of another sponge, to form a colony of perfectly identical creatures. A sponge colony is motionless. If the environment changes, the colony cannot move but can change shape. This happens as follows: some members of the colony are born, others - atrophy, or, as the researchers say, undergo involution.

A signal to involution for some members is formation of other members. The members of a growing colony use substances released after the old members atrophy as building materials. Since all modules of the colony are genetically identical, the death of some part of them does not damage the gene pool. Therefore, this ancient extinction mechanism served exclusively for changing the colony shape and did not promote evolution of modular organisms.

In the course of evolution, animals reproducing in an asexual way started to separate completely from each other. A lot of Polychaeta worms can reproduce by division or even by gemmation, but each derived organism already lives separately. However, in such way of reproduction, gemmation of descendants causes involution of parental tissues as before.

... more about:
»AGE »Metazoa »colony »death »gemmation

The difference is that the parental organism dies in this case, so, in A.V. Makrushin’s opinion, this can be already considered ageing. However, such ageing does not impact the evolution yet, because the genotype of the parents that died of old age continues to exist in their offsprings. However the Metazoa animals continued to evolve and finally did away with gemmation. Each of their offsprings, with the exception of monozygotic twins, possessed a unique genotype, and the loss of an individual was an irreplaceable genetic loss. And the mechanism of gerontal involution of tissues, which was preserved by these advanced creatures, resulted now not only in the death of a single individual, but in changing the gene pool of an entire species. Thus ageing began to influence the species evolution.

All Metazoa animals are descendants of modular organisms, from which they inherited ability to gerontal tissue involution. This is a universal and very ancient mechanism of ageing. Probably, it originated several times in the course of evolution of different groups of modular multicellular animals.

A.V. Makrushin also gives other examples where, from his point of view, ageing happens according in line with other mechanisms. For example, some hydra species die a natural death, having completed reproduction, but some adult insects die of hunger as their oral organs are underdeveloped. Their life span is determined by the fat reserve accumulated during their larval existance.

However, the primary ageing mechanism of the multicellular is gerontal tissue atrophy. Now, this mechanism is a key part of evolution, including human development, which means we have to grow old.

Nadezda Markina | alfa
Further information:

Further reports about: AGE Metazoa colony death gemmation

More articles from Life Sciences:

nachricht Strong, steady forces at work during cell division
20.10.2016 | University of Massachusetts at Amherst

nachricht Disturbance wanted
20.10.2016 | Max Delbrück Center for Molecular Medicine in the Helmholtz Association

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Innovative technique for shaping light could solve bandwidth crunch

20.10.2016 | Physics and Astronomy

Finding the lightest superdeformed triaxial atomic nucleus

20.10.2016 | Physics and Astronomy

NASA's MAVEN mission observes ups and downs of water escape from Mars

20.10.2016 | Physics and Astronomy

More VideoLinks >>>