From more than 3 billion years ago, the first life was born on the earth, and there are countless species of organisms that have appeared on the earth today, but now most of them have disappeared into the long river of history.
Why? Because the Earth's climate is changeable, the most typical is the alternation of ice ages and interglacial periods. When the ice age arrives, permanent glaciers and ice caps appear on land that persist all year round, and during the interglacial period, these glaciers and ice caps all melt. Of course, the change of the Earth's climate is not only the alternation of cold and heat, the atmospheric composition, humidity, oxygen content, etc. are constantly changing, and sometimes there will be a long period of extreme climate. It is not an easy task for organisms to survive such a climate-changing Earth, some organisms will completely become extinct in the process of climate change, and some organisms will evolve to adapt to new environments.
It is precisely because of the extinction and evolution of living things that the earth is different in each period, and few organisms have been able to survive on such a climate-changing earth to this day.
But it's not nothing, and sea spiders are an exception. Sea spiders and we are familiar with the land spiders or have a certain relationship, they belong to the claw sub-gate, and in terms of appearance and form, sea spiders and some species of spiders are quite similar, such as the "ghost spider" that can often be seen in the living room, the biggest feature of this spider is that the legs are very long, and the body is very small, and the sea spider is basically this form. Although sea spiders are related to land spiders, they have a much older history than land spiders.
The oldest fossil sea spider that can be dated is now 500 million years old, suggesting that this small animal that lives in the ocean has been on Earth for 500 million years.
This is a rather surprising thing, to know that in the past 500 million years, the Earth's climate has undergone many changes, including five extreme weather caused by mass extinctions, and sea spiders have not only survived, but almost no changes, they have not evolved to adapt to the environment, but can thrive in different historical periods. Let's first review how climate change caused extinction. The extinctions caused by climate change can be broadly divided into two categories, namely direct extinction and indirect extinction.
Some organisms are inherently less adaptable to their environment, so when the climate changes, they will bear the brunt of extinction.
There are also some organisms, their adaptability to the climate is very strong, but the climate change has led to the extinction of other animals and plants, and these animals and plants are precisely the food for the survival of this animal, so they eventually go to extinction due to food shortages. In addition, the new climatic environment will give birth to new species, and some animals, although they have withstood changes in the environment and survived the shortage of food, have eventually perished because the new natural enemies are too fierce. It can be seen that there are two core problems in the existence of a species, that is, eating and being eaten, and these two things, sea spiders are very good at grasping.
First of all, eating, sea spiders are not short of food under any circumstances.
The body of the sea spider is very small, and most sea spiders are less than a centimeter long, so its stomach cannot hold too much food, and it does not need much food. In general, the food of the sea spider is mainly based on the body fluids and moss of marine mollusks, and without these two things, any organic matter that can be eaten into the mouth can become its food, so no matter how the climate changes, the sea spider will not have a shortage of food. Next, we can talk about being eaten, do sea spiders have natural enemies? No, and not always, almost none of the sea creatures feed on sea spiders, because sea spiders really don't have anything to eat. The body of the sea spider has a small torso and eight legs, each with claws on the tip of the foot and pincer feet on the appendages.
Although the sharp claws of sea spiders cannot cause serious damage to other animals, they can also bring a lot of suffering to predators.
Most importantly, even if you catch the sea spider in pain, there is nothing delicious about this thing, and you can't find two pieces of meat that can plug the gap between your teeth. This characteristic of the sea spider can be seen at a glance, so in the past 500 million years, no animal has been interested in it. Without worrying about eating, and not being eaten, it can be said that the sea spider can survive all the time because of its own "simple enough". So complexity does not necessarily mean strength, and simplicity is sometimes the magic weapon of undefeated. This is actually a kind of survival wisdom, sometimes we are in a complex environment is difficult to get out of trouble, the most effective way at this time is to make yourself simple enough, as long as you are simple enough, no matter how complex the environment can not hurt you.