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Borneo is home to the world's only silver langur and proboscis monkey, yet an unusually rare hybrid monkey has emerged in Borneo's rainforests.
This hybrid monkey has the characteristics of a silver langur and a proboscis monkey, and exhibits something unique that no other monkey has.
To this day, scientists have not been able to explain why this type of monkey, known as the "hybrid monkey", is so rare in Borneo, and what is the biological law of their appearance.
How exactly did this monkey come about?
One or two types of monkey chromosomes.
To understand exactly how this monkey came about, we first need to understand the biology of the silver langur and proboscis monkeys involved in the hybridization of this monkey.
Silver langurs, living in the rainforests of Borneo Island, are relatively thin and small, and their biggest feature is that their bodies are covered with silver hair, and they are called "white-haired monkeys" by the locals.
However, the hair color of the silver langur is not monoecious, so its hair color is not helpful for distinguishing between females and males.
Therefore, the mating of Borneo silver monkeys is not very selective between individuals, which makes it impossible to rule out the possibility of interbreeding with other species of monkeys in the process of breeding.
In the rainforests of Borneo, in addition to the silver langur, there is also a species of monkey called the "proboscis monkey", which, as its name suggests, is the nose in its face.
They generally enter the mating age at about 6 years of age and begin to reproduce, and like the silver langur, the proboscis monkey also has the characteristic of not paying attention to the distinction between mates, which also leads to the possibility of mating between them and the silver langur.
In the field of biology, the chromosomes of any kind of organism are fixed, and the number is also very stable, that is, the number of two chromosomes and their attached base sequences in the same species is also the same, and the number of chromosomes between different species will also be different.
This determines that in the process of reproduction, their chromosomes are hybridized one-to-one, and there is no possibility of cross-breeding, which also determines that the appearance of hybrid monkeys is very rare.
So let's first take a look at what the chromosomes of silver langurs and proboscis monkeys look like.
When the silver langur reproduces, it carries 44 chromosomes, or 22 pairs of chromosomes.
Among them, only one pair of sex chromosomes, the male hormone Y chromosome, is paired with the sex information carried by the egg in the X chromosome, and the characteristics of all other chromosomes are one-to-one.
In the proboscis monkey, the number of chromosomes it carries is 44, and it is also 22 pairs of chromosomes, and only one pair of sex chromosomes in these 44 chromosomes has different characteristics.
During mating, when their sperm and egg are fertilized, the chromosomes of both are paired one-to-one, a process also known as "homologous pairing".
Second, the emergence of hybrid monkeys.
Since it is impossible for cross-breeding between two species of monkeys to occur, how exactly did the emergence of hybrid monkeys come about?
After some research, scientists found that the production of hybrid monkeys is not actually the first time in the world, but in the last world, there were also hybrid monkeys produced by cross-crossing between silver langurs and proboscis monkeys in the Xinjiang region of the mainland.