Discussion of everything related to the Theory of Evolution.
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During dry spell a pond will get dried up. No life can be seen, fishes etc. However, after rain the pond gets filled up and we can see fishes and other aquatic life.
How this could be? Where did the fishes and other aqautic life come from?
looking forward to the answers ( scientifically).
maybe the fishes pops out suddenly in the pond....
Usually after rain, the water from a big pond (lake or river) will flow and form a line to several smaller ponds...then, the fish will swim there and it's the time for the crocs party....
Q: Why are chemists great for solving problems?
A: They have all the solutions.
Your explaination is logical but I'm looking at a pond where there is no streams going into the pond. Totally isolated pond brother!
Where are you from?
I know at least in Africa that some fish can bury themselves during drought and survive until the pond is filled again. Other aquatic life forms also have dry resistant eggs that will survive the drought and span when the water comes back.
But these were things I read long ago, and even if my life was at stake I couldn't find the references
I once watched a documentary about the phenomena you are describing. This usually occurs in places that are dry for long periods of time and experience sudden rainfall a few times. The animals (and plants) that live in such conditions have developed a way to ensure that there species will live on, despite the arid conditions. For example, frogs will lay eggs that once exposed to water ,ie sudden rainfall, will hatch and develop into mature frogs much more rapidly than normal. The same goes for plants. The seeds will flourish and grow once they are supplied with water. During dry periods, the seeds remain in a dormant state. The point of this evolutionary development is to take advantage of the rare wet periods and allow the species to survive. The rapid maturation of the animal and plant life is to allow new seeds and such to be produced and continue the cycle.
I think the same might apply to the fish you are talking about, although I could be wrong...
I'm from Malaysia. Appreciate replies from you guys. As KaylethGrey and Canalon has explained, there seems to be no references which justifiy their replies.
However, I will still await for anyone who could clear my doubt which has been bothering for years.
i found this excerpt, but it only talks about plants:
Annual or ephemeral plants remain in seed form for much of their existence. After a rain, the plants go through a rapid growing season, sprouting, blooming and producing seeds in the course of a few weeks or months.
http://www.envmedia.com/guides/north_am ... biomes.htm
Here is more on plants:
Each season's unique precipitation pattern falls on a huge variety of mini-environments. And each year in each of these tiny eco-niches, a different medley of plants bloom as different species thrive.
Desert plants must act quickly when heat, moisture and light inform them it's time to bloom. Ephemerals are the sprinters of the plant world, sending flower stalks jetting out in a few days. The peak of this bloom may last for just days or many weeks, depending on the weather and difference in elevation. The higher one goes, the later blooms come. Different varieties of plants will be in bloom from day to day, and even hour to hour, since some open early and others later in the day.
but i found something on invertebrates:
Most invertebrates have a four-part life cycle that increases their ability to survive in a hostile (unfriendly) environment. The first stage of this cycle is the egg. The egg's shell is usually tough and resistant to long dry spells. After a rain and during a period of plant growth, the egg hatches. The second stage is the larva (immature), which may actually be divided into several stages between which there is a shedding of the outer covering, or skin, as the larva increases in size. Larvae have it the easiest of all in the desert, often being able to spend a portion of their life cycle below the ground where it is cooler and more moist than on the surface. Some larvae store fat in their bodies and do not even have to seek food. The third stage of development is the pupal stage. During this stage, the animal often lives inside a casing, in a resting state, which may offer as much protection as an egg. Finally, the adult emerges.
http://www.galeschools.com/environment/ ... animal.htm
something about frogs from the same place:
Amphibians are vertebrates (animals with backbones) that usually spend part, if not most, of their lives in water. Unlikely as it seems, such animals can be found in a desert. Frogs and toads both manage to survive in significant numbers in desert environments.
The short, active portion of their lives occurs during and immediately after the seasonal rains, when pools of water form. Mating, egg-laying, and young adulthood all take place in these pools. Those that survive into maturity leave the pools and take their chances on the desert floor where they are able to spend a few weeks feeding on both plants and insects. They must find shade, however, or risk dying in the heat of the Sun.
"I know how exciting pillaging is," the giant said fondly, ruffling Jack's hair. "No matter how much you're tempted, just say no."
"Just say no to pillaging. You got it."
- Taken from The Sea of Trolls by Nancy Farmer (Read it!)
You may also be thinking of dipnoi fish. They are some very evolved fish, which, during the dry part of the year in the munsonig region live in the mud that is formed when the water evaporates. They can do so by using a special organ to breathe, some sort of primitive lung, that is just an extension of the digestive tract, just like the gasous vesicle(has the same embriologic source too). The native people to these regions have learnt that these fish are very easy to catch. They just look at the mud, and wherever they see bubles rising they stick a harpoon and catch it.
Reference: any high-school zoology book
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter
That's it! But since my High school days (and the books too) are long gone, I didn't know where to find any references. Thanks
Lol.. I can give the name of my books, by i don't they would be of any use. I could check Campbell book, but i am lazy...
Try a comparative anatomy book, like Kardong's "Vertebrates". It even explains the mechanism behind these lungfishes' adaptation to drought.
Quote from p. 97, "Vertebrates" by Kardong 2nd ed. (from a figure):
"Reduced basal metabolism requires only infrequent breating. The lungfish draws in fresh air through the neck of the burrow that maintains continuity with the environment above. While declining water still covers the swamp, the lungfish burrows into soft mud. As the water level drops further, the lungfish moves into a cocoon lined with mucus and maintains contact with air through breathing holes. While in the cocoon, it enters a gestative stage during which its metabolic rate drops and its respiratory requirements decrease."
Hope this helps.
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