I'm facinated with the various ways life found to make new life.
ok, how to make babies without a man...
1) budding. This is used by many 'simple' organisms like Jellyfish, Corals and tapeworms. In budding the adult grows a nubb that eventually falls off and grows into a new adult. Imagine having a mole that grew untill it just snapped off and made a new you. ick.
2) Fragmentation. This slightly wierder form of reproduction happins when an adult animal basically falls apart. The individual pieces then develop into new adults. This form of reproduction is found among certen small worms. Imagine just walking around when suddenly *blamo* you explode into 8 or 9 peices wich in turn grow up into adults and so on.
3)Parthenogenesis. True 'virgin birth'. This is most common ammong some fish, amphibians, lizards and most developed in some species of the insect family Hymenoptera. (wasps, bees and ants)
The egg can grow and develop into a baby without the need of sperm. This produces in essance clones of the mother, with little genetic change from one generation to the next.
two of my favorite examples of Parthenogeneiss.
In one species of wasp, the young queen lands in her chosen place and looses her wings. Now our queen has a problem, she didn't have a drone to fly with her and she is unfertilized. She lost her wings and can't find a mate on her own, what does she do?
The young queen lays a clutch of eggs. These eggs are unfertilized. The eggs develop anyway and grow into young drones. (All, unfertilzed eggs will develop into males) The new drones then mate with our young queen. The queen then lays fertilized eggs that develop into female workers. So not only are the drones tweaked clones of mom, but they are also the father of thier sisters.
The queen can at anytime choose the gender of her next batch of eggs by controling if the eggs get fertilized or not. She also chooses which of her daughters will be fertile or unfertile based on how the eggs are cared for and the larva fed. Nutrition determines if the young girls will be workers or new queens.
The second example is of a very clever parasite. There is a bacteria that infects some wasp speices. The bacteria short circuts the wasps reproductive ability so they can't use sperm to reproduce. (The bacteria can spread to a new generation through an egg but not through a sperm. The bacteria prevents the development of generations that produce sperm and thus would not be able to spread the bacteria) But if unfertalized eggs become males and fertalized eggs become females how can the bacteria make new girls?
The bacteria causes the unfertalized eggs to make an extra copy of its DNA in a process called Endoreplication. Now the egg has two sets of genes to work with and in effect has fertalized itself, makeing a new female.
Interestingly enough if you give the wasp an antibiotic you can 'cure' her parthenogenesis and she will go back to reproducing the old way.
wa:do
