By: carloscrc - 26 April 2016, 11:22
Compartir en Facebook
Mother Nature gives us another lesson doing things that scientists have been trying to do for years, and that’s human cloning.
Even though it’s not possible for humans to use cloning as a form of reproduction, some animals that reproduce sexually have done it as a secondary way to prevent extinction if they can’t find an available mate in their new environment.
Studies
American and Irish researchers made the historical discovery after a female shovelhead kept in captivity at the Henry Doorly Zoo in Omaha gave birth to a live female pup. In 2007, it became clear after extensive testing that the female pup had DNA that was identical to its mother’s DNA. There was no trace of male DNA. Sadly, the pup was killed shortly after its birth.
10. Sea Sponges
No wonder why the ocean is full of them, these amazing animals are composed of a mass of cellsand fibers without any true organs. The fact that such a simple animal has the capability to clone itself is rather remarkable. Sponges can duplicate themselves through a process called gemmulation.
Sponges can clone and heal
Even more amazing is the ability of the sponge to regenerate due to injury or predation. If part of the sponge is broken off, that part can survive on its own. It will grow into a completely new sponge that is genetically identical to the parent sponge.
9. Tapeworms
Parasitic tapeworms also possess the power to replicate themselves as their main form of reproduction. When the adult reaches the reproductive stage of its life cycle, it detaches a rear segment of its body called a proglottid. Animals and humans can become infected by these flat worms.
Multiple cloning
The proglottid, which is ripe with eggs, passes out of the body and is eventually ingested by another grazing animal. The result is a multitude of cloned tapeworms that will infect other unsuspecting victims. Tapeworms are even more dangerous because most people don’t know when they’re infected, which allows the parasites to spawn a clone army of worms.
8. Aphids
Aphids are masters of self-replication because they are capable of asexually reproducing all year long—up to 12 young a day.
Continuous cloning
The nymphs, immature aphids, shed their exoskeletons about four times before reaching maturity. In warm weather, 80 clones from one aphid are possible.
7. Jellyfish
They are able to reproduce sexually as well as asexually. These multitalented creatures are called medusa at adulthood.
Medusas
During spawning season, each medusa releases either sperm or eggs. In most species, the eggs are fertilized in open water. Once the young jellyfish finds a suitable spot to set up shop, the cloning begins. Basically, the polyp divides itself in half, which produces a genetically identical twin.
6. Marmokrebs
Recently a marmorkreb, German for “marbled crayfish”, astounded scientists after it was discovered that the sea creature reproduced without mating. Making history, the marbled crayfish is the first crustacean of its kind to clone itself by reproducing asexually.
All girls
These animals were discovered in the European pet trade during the 1990s. Afterward, it was found that the lineage of the crayfish was entirely female. Since then, there has been great concern that the marmorkreb is becoming an invasive species.
5. Boa Constrictors
In a rare moment in scientific history, a female boa constrictor gave birth to 22 young snakes that had no trace of male DNA in them.
Half Clones
The snakes are considered “half-clones” because they carry the WW chromosomes. The researcher who made the discovery speculates that the new finding will change the way that scientists look at how reptiles, especially snakes, reproduce.
4. Whiptail Lizards
A recent study revealed that certain species of animals can reproduce asexually if necessary but some whiptail species do it because they have no choice. It is reported that these parthenogenetic lizards have twice the number of chromosomes as other whiptail species.
Don’t need a male
This oddity makes it easier for the female to reproduce without needing the male’s genetic material. The result is all-female offspring carrying chromosomes that were paired from the mother alone.
3. Gall Wasps
Gall wasps are a truly resourceful group of insects. These wasps are particularly skilled at laying their young on virtually every major part of a plant or tree. They implant the eggs directly into the chosen part of the plant.
Clones of their mother
Since the females reproduce asexually, the unfertilized eggs mature into clones of the mother without the assistance of male sperm. With male gall wasps so rare, there are many female gall wasps that wait to impregnate other plants with their clones.
2. Komodo Dragons
In 2006, a monitor lizard, aka a Komodo dragon, gave birth to four babies at London Zoo. Even more extraordinary is that another dragon was expecting to give birth to eight additional babies that year. Both mothers were held in captivity, and reproduced asexually. Until this point, Komodo dragons had never been known to reproduce without male participation.
DNA tests
After conducting tests on the young males, it was confirmed that the babies were not an exact genetic match with the mother. Instead, the mother’s DNA was doubled to create the young and showed no presence of male DNA. Herpetologist Richard Gibson speculated that the lizards developed the ability to survive in isolated situations.
1. Hammerhead Sharks
Can you imagine how dangerous would it be id sharks were able to clone? Bad news, when hammerhead sharks begin cloning themselves asexually, they become even more of a biological threat. This happened to a female belonging to a species of hammerhead sharks known as the shovelheads in 2001.
Studies
American and Irish researchers made the historical discovery after a female shovelhead kept in captivity at the Henry Doorly Zoo in Omaha gave birth to a live female pup.
In 2007, it became clear after extensive testing that the female pup had DNA that was identical to its mother’s DNA. There was no trace of male DNA. Sadly, the pup was killed shortly after its birth.
