As the time passes, slowly our body shows many changes not only in its structure but also in its function. This process, called senescence, is what makes us become older and, as a result, leads us to death.
Nevertheless, it doesn’t happen to all the beings: some animals have something called “negligible aging”, which means their cells have a constant renewal cycle that allows them to be biologically immortal. For example:
1. Immortal Jellyfish (Turritopsis dohrnii)
This sort of jellyfish has found a way to cheat death by reversing its aging
process – when facing any harmful situation as starvation or physical damage,
it returns to its polyp stage until it finishes transforming all its cells into
a younger stage, a process that takes about three days.
Usually, the jellyfish dies by diseases or by being consumed by other animals.
Know more in: http://www.immortal-jellyfish.com/
Usually, the jellyfish dies by diseases or by being consumed by other animals.
Know more in: http://www.immortal-jellyfish.com/
2. Lobsters
As the time
passes,usually animals get old, suffer by the senescence
diseases and stop reproduction. However, lobsters are different: it
gets bigger, it starts reproducing more, it gets more active and, if it this animal
wants to, it can change its shell and rebuilt it all over again.
Studies suggest that this longevity is due to an enzyme called telomerase, which is responsible to repair long repetitive sections of DNA in the end of the chromosomes, usually just during embryonic stages. In lobsters, this enzyme is functioning in all of their body even in adulthood.
However, lobsters can die from diseases and also from predators (e.g. humans).
Know more in:
Studies suggest that this longevity is due to an enzyme called telomerase, which is responsible to repair long repetitive sections of DNA in the end of the chromosomes, usually just during embryonic stages. In lobsters, this enzyme is functioning in all of their body even in adulthood.
However, lobsters can die from diseases and also from predators (e.g. humans).
Know more in:
- Cong YS (2002). "Human Telomerase and It's Regulation". Microbiology and Molecular Biology Reviews66 (3): 407–425. doi:10.1128/MMBR.66.3.407-425.2002. PMC 120798. PMID 12208997.
- Wolfram Klapper, Karen Kühne, Kumud K. Singh, Klaus Heidorn, Reza Parwaresch & Guido Krupp (1998). "Longevity of lobsters is linked to ubiquitous telomerase expression". FEBS Letters 439 (1–2): 143–146.doi:10.1016/S0014-5793(98)01357-X.
3. Glass Sponge (Hexactinellid)
They are
the oldest living animals in the world, aging more than 15,000 years. Their
skeletal structure makes the glass sponge reefs very sensitive to sedimentation
and to physical disturbances from trawling activity, making this animal very
vulnerable when close to human population.
Know more in: http://cpawsbc.org/campaigns/glass-sponge-reefs
Know more in: http://cpawsbc.org/campaigns/glass-sponge-reefs
4. Planariam Flatworms
By cutting a planariam into pieces, in both longitudinal or traversal directions, this animal can regenerate all of its body over again, originating a complete organism. This capacity of proliferation and differentiation, added to its ability to not show any signs of age, is the reason why this animal is also called biologically immortal.
Know more in: http://www.nottingham.ac.uk/news/pressreleases/2012/february/immortal-worms-defy-ageing.aspx