http://news.bbc.co.uk/1/hi/sci/tech/5036618.stm Isn't evolution amazing? I can't wait to see some detailed reports of what this cave offers!
yup all the creatures are blind there you know... Especially the scorpions. Amazing...a different evolution. Proves Darwin once again. Actually since something like this is possible, a separate ecosystem in an isolated space...this raises my thoughts on probability of occurance of life outside Earth on other bodies... Thus moon Europa might harbor some life after all.
That is interesting, as the base source of energy for most organisms is sunlight, which drives photosynthesis, but in the lack of sunlight, these creatures survive in a closed ecosystem without the input of sunlight. And *that* would help in developing other planets too. :m:
Well actually the species were isolated from others but the ecosystem is definitvely not sealed. So there is likely to be an influx with biomass.
If there is a constant influx of, say plankton and algae it surely suffcices, no? What should they feed on otherwise?
There is life, abeit not so complex one, 3 km below the surface that is living in the rocks and was discovered in the world's deepest mines in South Africa. It's interesting that the organisms there are anaerobic and don't use oxygen, but still posess the genes for oxygen respiration, what possibly means that those organisms have descended from above. That ensures that life still would survive even after a total evoporation event due to massive meteor impact. Please Register or Log in to view the hidden image! Please Register or Log in to view the hidden image! For more information see: http://www.ambrosevideo.com/displayitem.cfm?vid=1178 Description ~~~~~~~~~~~~~~~~~~~~ The planet Earth was born out of chaos and disaster – and completely by chance. Episode 1 of Miracle Planet transports us to this breathtaking genesis, The Violent Past that created the fragile conditions for life itself. Featuring astounding high-definition visuals and interviews with pre-eminent scientists in the field, The Violent Past reveals the startling earliest history of life on Earth – its microscopic manifestations and the unimaginable challenges to its survival.
Well, lithotrophic bacteria should survive just fine. The only thing that would kill them off is probably complete loss of water or something similar.
CharonZ, the BBC article wasn't very clear. The lake is an underground lake inside the cave network. The entire ecosystem was shielded from outside water and nutrients by a thick layer of chalk surrounding the cave system. There is a little more information in this article: http://www.comcast.net/news/science...n=/2006/06/01/404667.html&cvqh=itn_newspecies
Thanks for the link, I probably have to retract my statement then. However, even this article is not very clear. I hope there will be a real publication, soon. At the very least there has to be an influx of oxygen into the system in the absence of phototrophs, otherwise the crustaceans would not be able to live (afaik they only stand a limited time of anoxia). However this would not be truly self-sustaining.
The article states that they believe that this is an "isolated ecosystem....creating a unique environment in which new species have evolved." Where do you get any idea that it was "connected" to an aerobic eco-flux? What are the possibilities that they adapted to an extremely limited - perhaps nearly totally limited - anaerobic environment?
Certain small crustaceans (flat horizontal crustaceans, small shrimp, crabs) can use both aerobic and anaerobic metabolism. In low O2 environments such as in the Black Sea and mudflats of mangroves species have evolved that replace oxygen using NADH for anaerobic respiration: glycolysis cycle for cellular respiration. Yeast also use anaerobic respiration. Annelids, molluscs, and crustaceans (crabs and prawns) live in the anaerobic mudflats of Sungei Buloh Swamp in Singapore. http://wetlands.sbwr.org.sg/text/95-2-2-2.htm "Hypogean crustaceans : Niphargus rhenorhodanensis and Niphargus virei. The results obtained showed that these organisms presented a high survival time in severe hypoxia. The strong resistance to the lack of oxygen measured in Niphargus is mainly due to a clear tendency to reduce their energetic expenditures linked to locomotion and ventilation, but also to an anaerobic metabolism based on the coupled fermentation of glycogen and amino acids, which is more efficient than the "classical" anaerobic glycolysis. Both hypogean crustaceans also showed high amounts of stored glycogen and arginine phosphate, which allow them to fuel their anaerobic metabolism efficiently and for a long time." http://groundwater-ecology.univ-lyon1.fr/FH/fh3.htm In sewage systems: "There is a rise in organisms that can survive an anaerobic environment e.g.: Sludge worms, Blood worms, Rat tailed maggots." http://www.visit-islay.com/biology/stg/biotech.html See also: "Nitrogen and anaerobic metabolism and haemocyanin levels in the white shrimp Litopenaeus vannamei exposed to short-term hypoxia," by Gomez-Jimenez, S., Lugo-Sanchez, M.E., Guzman-Partida, A.M., Garcia-Sanchez, G. and Barraza-Guardado, R., Proceedings of the Sixth International Symposium on Fish Physiology, Toxicology, and Water Quality. R.V. Thurston (ed). 2003. U.S. Environmental Protection Agency, Ecosystems Research Division, Athens, Georgia, USA. EPA600/R-02/097. Crested Auklets use anaerobic respiration when they dive. http://www.aquariumofpacific.org/ANIMAL_DATABASE/animaldb.asp?id=79 As an interesting side note, I just learned that certain anaerobic bacteria can dissolve mercury.
yes variations in species certainly proves evolution Please Register or Log in to view the hidden image!
Called Ayalon Cave and it was supposedly sealed off from oxygen by the thick layer of chalk for 5 million years, a time when the Mediterranean Sea covered parts of Israel . Israel Naaman, assistant to team leader Amos Frumkin, Geography Department of Hebrew University in Jerusalem, "acknowledged the species were likely endangered from oxygen exposure during the discovery process." http://www.msnbc.msn.com/id/13068383/ "The underground cave includes an underground lake, in which the crustaceans were found. The lake is part of the Yarkon-Taninim aquifer, one of Israel's two aquifers, yet is different in temperature and chemical composition from the main waters of the aquifer. The lake's temperature and salinity indicates that its source is deep underground [sulphur compounds in the water]....Two of the crustaceans are seawater species and two others are types found in fresh or brackish (slighty salty) water." They are all DNA-unique scorpion and shrimp-like creatures that use bacteria as their basic food source. http://www.haaretz.com/hasen/spages/721895.html
What is the energy source? Are the bacteria the types that use sulfur compounds (like in geothermal vents) as their energy source, rather than photons trapped by chloroplasts?
To my knowledge no crustaceans are able to survive sustained anoxic conditions. Even higher eukaryotic organisms have a partial anaerobic respiration (lactate formation is widespread for example). But as I said, from those paper I know most crustaceans have to move to oxic regions every now and then. Valich, if you have read the paper you linked to, you'd have seen that. Besides, the people standing near the lake didn't have breather from what I could see, so there is oxygen. Walter anaerobic bacteria can gain energy either by fermentation and/or using certain other compounds as terminal electron acceptor instead of oxygen including Fe(III), sulfate, nitrate, fumarate, Mn(IV), U(VI) and so on. Eukaryotes usually only ferment.
I am not certain, but from what I have read in the popular press, the cave was uncovered by a mining operation. They were mining material for cement. I think the entrance to the cave complex was uncovered by digging into it. The opening didn't exist until the mining operation opened it up. I assume that oxygen has entered the cave only since the opening was made. The details are sparse, so I am not certain, but that is how I interpreted the scenario.
This is a possibility. I do not know how large the caves are but either there was a huge amount of air (with oxygen) trapped into the caves that is sufficient to have lasting oxygen over all these years (did they say something about million years or so?). In that case there would have been a steady decline in oxygen concentration. Alternatively or additionally there could have been a slow diffusion of oxygen. Afaik a lot of rock formations are oxygen diffusible, but the amount might be far too low to make a difference. I doubt a complete anoxic atmosphere due to the presence of a number of crustaceans mostly, as I am pretty sure that they do not survive constant anoxia. I am not that sure regarding worms, though. The oxygen influx is now probably an extreme problem for the anaerobic respiring bacteria I fear.
