It’s always hard to draw a parallel line when it comes to “two animals share with one body” or/and “one animal is conjoined with two heads”. While the most common animals with two heads or two faces like snakes, tortoises and cats do not always shock the experts, many other uncommon two-headed species and two-headed human as well, always shock the experts. Not surprisingly, there is always a controversy debate on this issue among the community.
A gene mutation refers to a permanent change in the DNA sequence of a gene which might alter/modify the amino acid sequence of the protein encoded by the gene itself. Gene mutation can either be inherited from a parent (called hereditary mutation) or acquired during a person’s life (called acquired or somatic mutation). The hereditary mutation is a type of mutation that can present throughout a person’s life in almost every cell of their body while somatic mutation can occur in the DNA of individual cells on the cause of environmental factors (such as ultraviolet radiation from the sun) or it might occur if a mistake is made during the time DNA copies itself during the stage of cell division or a mistake occurs when it is being replicated (in S phase of the eukaryotic cell cycle).
De novo mutation is another type of mutation that occurs in sperm cell or an egg just after fertilisation, explaining the reason of the presence of genetic disorders in an affected individual who has a mutation in each of their cell, although they have been brought up in a family without a record of such strange and rare disorder. Nevertheless, up to now, certain genetic disorders are extremely strange and unbelievable and they cannot be explained with a scientific theory alone.
In November 2008, this unusual kitten with two faces cat was born in Midvale. In the same year alone, in August, a kitten with four eyes, one mouth and two noses was born in Ohio, but it died after five days.
This two-headed kitten appeared to be healthy since it meowed and purred just like other normal cats. Its deformed appearance was believed to be the result of a congenital deformity which might have occurred in its early embryonic development.
One rare mutated fish with two heads was caught downstream of Lake Athabasca from Alberta’s oilsands region in 2008, and later the capture of this deformed fish sparking headline around the world. It was 2.5 kilogram in weight and was observed to have two mouths, one beneath the other. Its deformity was suspected to be linked with contamination of the Athabasca River. Scientifically, it’s common to see deformed fish that is caused by mutation during the increased of water temperature in the egg phase.