The larger the animal, the smaller the sperm. Does this statement sound ridiculous? In fact, it is the conclusion of scientific examination.
According to a recent report published in the British Science Journal’s Report of the Royal Society, the size of the reproductive organs of female animals determines the form of sperm produced by male animals: the number of sperm is large but the sperm is small or the sperm is small but bulky.
Researchers at Stockholm University and the University of Zurich participated in the study of the relationship between the size of the animal itself and the size of the sperm. The researchers conducted a sampling study of sperm from 100 different species of mammals.
Stockholm University scholar Sean Fitzpatrick, who participated in the research project, said: “Let’s take an example. For example, elephants, females have large reproductive organs, and semen first becomes thinner after entering the female reproductive organs. “”
In this case, it will become difficult for sperm to meet the egg and combine it into a fertilized egg. Fitzpatrick said: “So it has become more meaningful to produce a large amount of sperm from the beginning to ensure that some of the sperm can meet the egg.”
Compared with small mammals, the sperm is more convenient to encounter the egg. However, if a female animal mate with more than one male animal, there is also a competition between the sperm produced by these male animals. In this case, the bigger the sperm, the greater the chance of winning.
Of course, animals with large bodies will encounter the same problem. However, scientists have said that because of the large size of the animal’s reproductive organs, the size of the sperm is not so important.
Fitzpatrick made a metaphor. He likens the female reproductive organs to a huge stadium, and the sperm is the athlete standing in the stadium. “If the stadium is large, then the chances of players interacting with each other are small. On the contrary, if the stadium is relatively small, then the athletes are much more likely to collide in the process of moving toward a unified goal.”
The sperm of the fruit fly can be rolled up, and if it is straightened up to 6 cm, it is far beyond the size of the fly itself.
Among mammals, the spermatozoa of the house mouse is the largest in terms of body proportion. The sperm of humans and Asian elephants are relatively small.