Talked aboutLiceThese small creatures often appear in the hair of pets, and they can also be transmitted to humans, bringing many diseases, and they are quite unpopular.
But lice play an important role in scientists studying the evolution of human beings, and it has accompanied the evolution of human beings and solved the mystery of human "hair loss", but now it has disappeared from humans.
Lice belong to the winged subclass lice and like to parasitize onDense hairAmong the mammals, in humans, there are three places where lice parasitize, and they are named: body lice, head lice, and pubic lice.
Due to the different locations of the parasite, the body characteristics of these three lice and the harm they bring to humans are different, such as head lice parasitic on the head, causing a variety of diseases related to the scalp and hair loss.
Scalp structure. Lice can also be seen in clothing, and lice especially like to parasitize on the fibers of clothing, and then enter the human body from clothing.
Lice can only cling toBy sucking bloodIn order to live, the itching of the part that is sucked by lice is unbearable, and people can't help but scratch it, and then they will find a blood stain.
This blood comes from lice, and a large amount of blood flows out after being squeezed by humans, and these blood contains bacteria and viruses, which penetrate into the blood circulation through the bite part of the lice on the human body, inducing diseases.
Regression feverIt is the most common disease in the world, caused by lice, the symptoms of the patient appear periodic fever and body pain, and the liver will be abnormally swollen in severe cases, which seriously endangers human health.
Relapsing fever symptoms.
However, it is such a parasite that is harmless, and scientists have found the evolutionary process of their ancestors in it.
In the impurity report of the American "Public Biology Library", experts classified lice in humans according to DNA in order to study them.
Although the human lice are basically the same in size, through the study of the DNA of these lice, it is found that the main thing isTwo varieties
Based on the huge differences between the two species of lice, experts concluded that lice began to branch in humans 1 million years ago.
Abominable lice.
This is exactly the right timeCoinciding with the evolutionary history of humanity1 million years ago, they parasitized in the thick hairs of Homo erectus and Homo sapiens respectively, and they differentiated in different living environments.
But why do these two lice appear in our modern bodies at the same time?
Prior to this, it has to be mentioned that the order of human evolution is Homo sapiens, Homo erectus, Homo sapiens, and modern humans, and the time periods of life of the two adjacent races overlap, which also gave the ancestors the opportunity to contact each other.
The answer is actually very simple, Homo erectus lice were transmitted from Homo erectus, and Homo erectus passed the lice to Homo sapiens, which in turn passed on to modern man.
All kinds of races. The species of lice on each species is different, and it is passed on to modern peopleTwo types of lice, precisely from Homo sapiens and Homo erectus.
American scientists speculate that after Homo sapiens came out of Africa, traveled all over the continent and lived well in various places, at this time, Homo sapiens met the ancient race of Homo erectus, and the two sides had intimate contact before Homo erectus disappeared.
Because lice can only be transmitted in close interactions, such as fighting, mating, and wearing the same unwashed garment.
This discovery is undoubtedly the sameShockingPreviously, scientists had believed that the various races were too far apart and that there was too much of a divide to make it impossible to socialize.
There is not much overlap between different races.
German anthropologist Max Planck disagrees with this, as there is insufficient evidence that the ancestors of human lice were the same species 1 million years ago.
But the mainstream of the scientific community is that lice are useful for studying humansEvolutionary HistoryIt is of considerable value that humans can get a glimpse of the iceberg of evolution by studying lice.
After all, lice have been around much longer than humans, and scientific studies have shown that lice have been parasitic since the time of the dinosaursBirds and dinosaursIn the body, the dinosaurs that have been infested with lice are also quite short-tempered.
The process of lice growth.
Another study showed that lice are closely related to the development of species, because lice and species are parasitic, and as the species changes, the lice will also change, so studying the genes of lice can infer a simple evolutionary history of the species.
Since lice accompany the evolution of species, why have lice mysteriously disappeared in modern society today?
Strictly speaking, lice didn't really disappear from humans, butThe number is reduced, the impact on humans is smaller, or rather temporarily, gone.
The first reason is the evolution of human beings, from the ancient polychaete primates to the modern human race, the human body has undergone tremendous changes.
Hair is getting less and less in evolution.
One of the biggest things isHair declineHuman hair has become less noticeable and more sparse, and it is even difficult to observe the female body hair in modern society with the naked eye.
You must know that lice prefer to live in places with thick hair, and due to the reduction of the living environment, the number of lice will naturally decrease.
The second point is because, peoplestandard of livingThe improvement of love, the more clean it is, and it is difficult for lice to survive in the human body.
At the beginning of the last century, the number of lice on the body of our people was generally high, because in that era, there was not enough food and clothing, and they thought about how to survive every day, so they naturally had no time to take care of the cleanliness and hygiene of their bodies.
If you don't pay attention to hygiene, lice will take advantage of it.
Often a piece of clothing is worn for a week and a month without washing, and it has become the norm for people not to take a bathLice growTarget.
And in that poor era, the clothes of the family were often borrowed from each other, and the younger brothers and sisters waited for the clothes of the older brothers and sisters to change their clothes.
There is no time to clean during the process, which greatly increases liceEfficiency of propagationAs long as one person in the family has lice, then the family will basically be infected with lice.
Clothing contamination is often overlooked.
After entering the modern society, people's material living standards have improved, and they do not have to worry about food or clothing, so they naturally have the kung fu of grooming and dressing.
Especially in today's new era, people wear all kinds of clothes, they have to change their patterns every day, and the clothes are a little dirty and thrown into the washing machine, so it can be said that the frequency of people changing clothes in modern society is higher than the frequency of people taking baths in modern society.
Clothing carries all kinds of bacteria.
As for modern people taking baths, it is even more frequent, and one wash a day has become the norm.
The lice living on people complained bitterly, saying that they couldn't survive, and they ran away with the station tickets they bought overnight.
Why yesDisappears temporarilyWhat about it? Because as long as someone doesn't like to be clean, lice will definitely return to people's bodies.
Nowadays, there are still many poor mountainous areas in China, and the local people live a poor life, and they may not pay so much attention to life, and they will inevitably have lice on their bodies.
In addition, many stray cats and dogs on the street also have lice on their bodies, so be careful to keep your distance from them and never get in close contact with them just because you think they are cute.
Small animals can carry a variety of parasites.
The harm of lice in the human body is quite large, don't look at the early stage of only a few small, but the reproductive efficiency of lice is quite high, more fierce than the donkey of the production team.
Studies have shown that lice live only 6 weeks and larvae need only 2 to 3 weeks to become adult offspring.
Terrible lice eggs.
Each female adult can lay 10 eggs per day, and the eggs of lice hatch very efficiently, they can hatch in 8 days, and the hatching pups immediately parasitize and suck blood.
If the disease caused by lice infection has serious consequences, the patient must shave the hair of the parasitic lice area and then clean it with a professional agent, which is very troublesome and affects people's image.
In 2014, in the British report, there was a little girl with lice on her head, and the reporter grabbed a lot of it on the little girl's head, which was quite infiltrating.
Therefore, in order to prevent lice parasitism, we must pay attention to personal hygiene, change clothes frequently, bathe frequently, and often go to the sun to bask in the sun, so as to have a healthy life.