Sunday, March 29, 2009

Brahmapuranam - 7 islands - now 7 continents, are they same?

We all have studied that there are 7 continents in the world, i.e.
1) Africa,
2) Antarctica,
3) Asia,
4) Europe,
5) North America,
6) South America and
7) Australia.

Recently, I came across an interesting article in which it was mentioned in ancient Hindu literature Brahmapuranam that long before any transformations took place on earth, there were 7 islands, i.e.
1) Jambu,
2) Plaksha,
3) Shalmalee,
4) Kusha,
5) Krouncha,
6) Shaaka and
7) Pushkara.

Are these the same continents that we have learnt in schools?

Also, interesting to note is that all these were individual islands, which later got attached or detached due to various reasons and got transformed into present state.

Labels: ,


Saturday, March 07, 2009

Turritopsis nutricula - The world’s only “immortal” creature

From Wikipedia, the free encyclopedia
http://en.wikipedia.org/wiki/Turritopsis_nutricula

Turritopsis nutricula is a hydrozoan with a life cycle in which it reverts to the polyp stage after becoming sexually mature. It is the only known case of a metazoan capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage [2]. It does this through the cell development process of transdifferentiation. Theoretically, this cycle can repeat indefinitely, rendering it biologically immortal.

Description
Turritopsis nutricula has a diameter of about 5 millimetres (0.20 in). It has an equally high and bell-shaped figure. The walls are uniformly thin. The bright red, big stomach has a cruciform shape in its cross section. Young specimens have only eight tentacles along the edge, while adult specimens have 80-90 tentacles.

Distribution and range
The species is originally from the Caribbean but has spread all over the world.[3] T. nutricula are found in temperate to tropical regions in all of the world's oceans. Turritopsis is believed to be spreading across the world as ships ballast water is discharged in ports.

Life cycle
The fertilized eggs develop in the stomach and in the screen formed by the cave in the jellyfish planula. The eggs are then planted on the seabed in polyp colonies. The jellyfish hatches after two days. The jellyfish becomes sexually mature after a few weeks (the exact duration depends on the ocean temperature; at 20 °C (68 °F) it is 25 to 30 days and at 22 °C (72 °F) it is 18 to 22 days).

Immortality
Jellyfish usually die after propagating; however, the Turritopsis nutricula has developed the ability to return to a polyp state. This is done through a cell change in the external screen (exumbrella). The ability to reverse the life cycle is probably unique in the animal kingdom, and allows the jellyfish to bypass death, rendering the Turritopsis nutricula biologically immortal.

Labels: , ,


This page is powered by Blogger. Isn't yours?

Subscribe to Posts [Atom]