Most animals age via at least two mechinisms: at a "macroscopic" level, basically wear and tear to the point where (on evolutionary time scales) it's more genetically advantageous to optimize for ...
Several companies are commercializing tests for telomere length such as this one here. I understand the basic mechanism for why telomeres shorten during DNA replication, but how good is the evidence ...
I have heard that the Hydra organism is biologically immortal (later I found that there are more immortal organisms). Now I know that its immortality is related to its telomerase. The thing is that we ...