The Immortal Jelly

Here is an amazing creature! Turritopsis nutricula is a hydrozoan, a jelly. They aren't called jellyfish anymore, by the way. Now they are called jellies. Nom! Only I don't want to eat this one on toast, I want scientists to study it. Why? Well, it's basically immortal.

After it reaches sexual maturity, it can go through a process of transdifferentiation and transform mature cells back to young cells (polyps). Here's one way to explain it:

Cell transdifferentiation is when the jellyfish "alters the differentiated state of the cell and transforms it into a new cell. In this process the medusa of the immortal jellyfish is transformed into the polyps of a new polyp colony. First, the umbrella reverts itself and then the tentacles and mesoglea get resorbed. The reverted medusa then attaches itself to the substrate by the end that had been at the opposite end of the umbrella and starts giving rise to new polyps to form the new colony. Theoretically, this process can go on infinitely, effectively rendering the jellyfish biologically immortal. (Wikipedia)

This little creature is about 4.5 mm in diameter (.18 inches). The red in the center is its large stomach. Young jellies have about 8 tentacles while adults have 80-90 tentacles. The picture shown below is actually a Turritopsis rubra from New Zealand which is closely related. They are very similar, but it's not known if  T. rubra can transform back into polyps.

The jelly originated in the Carribbean but now it's found all over the world in temperate to tropical oceans. Because it's basically immortal (if it doesn't succumb to predation, etc), the numbers are spiking.  They think it's spreading by ships discharging ballast water in ports.

A bit more about their immortality:

Random Thoughts About Human Impact On Evolution

Charles Darwin celebrated his 200th birthday February 12 of this year. So of course many of the science podcasts I listen to, as well as many of the science and skeptic sites I visit, have been talking about evolution and Darwin and all that good stuff. Evolution is often paraphrased as the term, survival of the fittest, which is inaccurate. Here is how Dictionary.com defines it, as well as some other terms, just so we're all on the same page:

• Survival of the Fittest
  a 19th-century concept of human society, inspired by the principle of natural selection, postulating that those who are eliminated in the struggle for existence are the unfit.


• Natural Selection
  n. The process in nature by which, according to Darwin's theory of evolution, only the organisms best adapted to their environment tend to survive and transmit their genetic characteristics in increasing numbers to succeeding generations while those less adapted tend to be eliminated.


• Evolution
  Biology. change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift.

I've been slowly forming some random thoughts regarding the human population and evolution and I thought I'd write them down. Your input would be most welcome, as usual.

Animal Jihad, The Furry Holy Wars, Part Squirrel