CATDOLL : CATDOLL: Is sea urchin viscera poisonous?

Is sea urchin viscera poisonous?

It is poisonous. There are two organs in sea urchins that produce toxins: spines and thorns. In the reproductive season, eating the gonads and ovaries of sea urchins or being stung by spines or thorns can cause poisoning. Dozens of sea urchins have been reported to be poisonous, including the white-spined three-line sea urchin, the ball sea urchin, the poisonous sea urchin, and the stone pencil sea urchin.

Earth Science: Try to describe the evolution of life on Earth, how to strive for a bright future for human evolution, and some thoughts on the evolution of life? Thank you!!

I can only answer the following about the evolution of life:

Origin of Life

The origin of life should be traced back to the origin of elements and chemical molecules related to life. Therefore, the origin of life should start from the beginning of the formation of the universe, through

The so-called "Big Bang" produced carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur and other main elements that constitute life.

About 6.6 billion years ago, a huge explosion occurred in the Milky Way. After a long period of condensation, the fragments and scattered matter formed the Milky Way about 4.6 billion years ago.

The Earth, a member of the solar system, was also formed 4.6 billion years ago. Then, the cold nebula material released a large amount of gravitational potential energy, which was then converted into kinetic energy.

Energy and heat energy cause the temperature to rise, and the radioactive heat energy of the elements inside the earth also increases the temperature, so the early earth was in a molten state.

As the sphere rotates, the matter inside it differentiates. The heavy elements sink to the center and condense into the core, while the lighter matter forms the mantle and crust. Gradually,

This process took a long time, and the original crust appeared about 3.8 billion years ago, which is consistent with the age of most rocks on the moon's surface.

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The origin and evolution of life are closely related to the origin and evolution of the universe. The constituent elements of life, such as carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur, come from "

The evolution of elements after the Big Bang. Data show that chemical evolution in the pre-biological stage is not limited to the Earth, but exists widely in the universe.

In interstellar evolution, some biological single molecules, such as amino acids, purines, pyrimidines, etc., may be formed in interstellar dust or condensed nebulae, and then on the planet.

Under certain conditions on the surface of stars, biological macromolecules such as polypeptides and polynucleotides were produced. Through several transitional forms of pre-biological evolution, they eventually formed on Earth.

The most primitive biological system, that is, life with primitive cell structure, was formed. From then on, the evolution of biology began, and countless complex organisms have appeared on the earth until today.

Life form.

3.8 billion years ago, stable land masses formed on Earth, and various evidences indicate that the liquid hydrosphere was hot, even boiling.

Archaea and methanogens may be the closest to the oldest life forms on Earth, and their metabolism may be chemolithoautotrophic.

The 3.5-billion-year-old microbes in that group may be the earliest evidence of life on Earth.

The emergence of the primitive crust marked the transition of the Earth from the astronomical planetary era to the geological development era, and life with primitive cellular structure began to gradually form.

However, for a long time, not many organisms appeared. It was not until the Cambrian period 540 million years ago that shelled metazoans appeared in large numbers.

1. [Precambrian]

The Archean is the oldest period in geological history. From the perspective of the biological world, this is the initial stage of the emergence of primitive life and biological evolution.

There were very few prokaryotes, and they left only a few fossil records. From the perspective of the non-living world, the Archean Eon was a period of thin crust, steep geothermal gradients, volcanic-rock

It is also a period when magma activity is intense and frequent, rock formations are generally deformed and metamorphosed, the atmosphere and hydrosphere lack free oxygen, and a series of special sediments are formed;

It is a period when the siliceous-aluminous crust is formed and continues to grow, and it is also an important mineralization period.

In the early Proterozoic, some relatively stable continental plates with large thickness appeared on the surface of the earth.

The Proterozoic showed a more stable structure than the Archean. The atmosphere in the late Proterozoic contained free oxygen, and with the increasing prosperity of plants

With the continuous strengthening of photosynthesis, the oxygen content of the atmosphere continued to increase. In the middle and late Proterozoic, algae were very prosperous, which was obviously different from the Archean.

The Sinian period is a unique geological period in the last part of the Proterozoic Era.

The Sinian Era contains a large number of animal fossils, which is different from the Proterozoic Era, which does not contain reliable animal fossils. However, compared with the Cambrian Era, which is rich in animal fossils with shells, the Sinian Era

The fossils contained in the system are not only monotonous in type and small in number, but also very limited in distribution. Therefore, it is still impossible to use the animal fossils in it for effective biostratigraphy.

The most prominent feature of the Sinian biological world is the emergence of a large number of non-shelled metazoans in the later period, and the appearance of a small number of small shelled animals in the late period.

Advanced algae flourished further, some new types of micro-paleontology appeared, and stromatolites flourished in the early Sinian Period, but their number and types suddenly declined in the later period.

From the perspective of the tectonic state of the lithosphere, several large, relatively stable continental plates had already appeared on the surface during the Sinian Period, and above them were typical

The cover sediments are similar to those of the Paleozoic. Therefore, the Sinian Period can be considered a transitional stage between the Proterozoic and Paleozoic Eras.

2. Cambrian Period

The Cambrian period is the first period of the Paleozoic Era, which began 540 million years ago and lasted for 40 million years.

During the second great development period, there appeared rich and diverse and relatively advanced marine invertebrates, and a large number of fossils were preserved, making it possible to study the life at that time.

The conditions of the physical world, and the use of biostratigraphic methods to divide and compare strata, and further study the relatively complete development history of the organic and inorganic worlds.

The more famous ones include the Chengjiang fauna in Yunnan during the Early Cambrian and the Burgess Shale biota in Canada during the Middle Cambrian.

Mainly vertebrates and marine algae. Many advanced classes of invertebrates such as arthropods, echinoderms, mollusks, brachiopods, graptolites, etc.

All of them have representatives. Among them, the trilobites in the arthropod phylum are the most important, followed by brachiopods. In addition, the ancient cups, ancient ostracods, soft tongue snails,

Conodonts and nautiloids are also very important. Apart from conodonts, there are many other representatives of higher chordates, such as the Chengjiang Fauna in Yunnan, my country.

The Chinese eel, Yunnan fish, Haikou fish, etc., the skin worms in the Burgess Shale in Canada, and the duck-scale fish in the Upper Cambrian of the United States.

3. [Ordovician]

The Ordovician period is the second period of the Paleozoic Era, which began 500 million years ago and lasted for 65 million years.

In the platform area within the plate, seawater is widespread, which is manifested in the widespread development of coastal shallow marine carbonate rocks.

The geosyncline area is a deep-water environment, forming thick shallow-sea and deep-sea clastic deposits and volcanic eruption deposits.

During the great ice ages, its distribution range included Africa, especially North Africa, Argentina and Bolivia in South America, and Spain and southern France in Europe.

The biological world in the Ordovician period was more prosperous than that in the Cambrian period. Marine invertebrates developed unprecedentedly, among which graptolites, trilobites, nautiloids and brachiopods were the most abundant.

The corals and stromatoporoids in the cnidarians, the sea lilies and crinoids in the echinoderms, the ostracods and bryozoans in the arthropods also began to grow in large numbers.

Appear.

In the middle of the Ordovician period, primitive vertebrates, such as the heteroscelids and the sphenodonts, appeared in the Rocky Mountains of North America and also in Australia in the southern hemisphere.

Heteropods appeared, and plants were still mainly marine algae.

4. [Silurian] Graptolite era, land plants and jawed animals appeared

The Silurian period is the last period of the Early Paleozoic Era. It began 435 million years ago and lasted for 25 million years.

It developed well on the Baltic island of Gotland, so it was once called the Gotland system.

The tripartite nature of the Silurian is quite obvious. Generally speaking, marine transgression occurred everywhere in the Early Silurian, reached its peak in the Middle Silurian, and had different characteristics in different places in the Late Silurian.

The degree of sea retreat and land rise shows a huge transgression cycle. In the late Silurian period, the crustal movement was strong, the ancient Atlantic Ocean closed, and some plates developed

The collision caused some geosynclines to rise, the paleogeography changed dramatically, the continental area expanded significantly, and the biological world also underwent a huge evolution. All of this marked

It marks a turning point in the development of the earth's crust history.

Compared with the Ordovician, the biological landscape of the Silurian had further development and changes. Marine invertebrates still played an important role in the Silurian, but

The species replacement and internal composition of the phyla have changed. For example, the Graptolites retained the Diplograptids, and the newly emerging Monograptids also flourished;

The structure became more complex, such as the order Pentachaetes, the order Lithocarpus, and the order Microcarpus developed; the cephalopods and nautiluses in the mollusks decreased significantly, while the bilaterians

The crustaceans and gastropods gradually developed; trilobites began to decline, but the arachnids and ostracods developed rapidly; the horseshoe crab, also known as the "sea scorpion", among the arthropods

Widely distributed in the oceans in the Late Silurian; Anthozoa further flourished; among echinoderms, the number of crinoids decreased greatly, and crinoids appeared in large numbers in the Silurian.

Among vertebrates, jawless fish further developed, and jawed armored fish and acanthid fish appeared. This was a major event in the evolution of vertebrates.

They began to conquer the waters, creating conditions for the great development of Devonian fish.

In terms of plants, apart from the flourishing marine algae, at the end of the Late Silurian, the terrestrial ferns first appeared, and plants finally began to grow from water.

Development towards land is another major event in biological evolution.

5. [Devonian] The Age of Fishes

The Devonian period is the first period of the Late Paleozoic Era, which began 410 million years ago and lasted for about 55 million years.

The appearance of the earth has changed greatly compared with the early Paleozoic Era, which is manifested in the expansion of land area, the development of continental strata, and the great changes in the appearance of the biological world.

Land plants and fish-like animals developed unprecedentedly, amphibians began to appear, and the composition of invertebrates also changed significantly.

Brachiopods developed rapidly in the Devonian Period. The Lithocera, which appeared in the Silurian Period, became important fossils of the Devonian Period.

Holeless and smallmouthed clams are also extremely important in the division and comparison of Devonian strata.

Foam-type and two-banded tetracorals flourished. In the Early Devonian, foam-type was dominant, and two-banded corals began to emerge; in the Middle and Late Devonian, two-banded corals dominated.

Coral occupies the main position.

The number of nautiloids decreased greatly, while the ammonites such as the plethodontids and the tridentatids flourished.

Most of the orthograptids became extinct, with only a few representatives of the Monograptid family remaining in the Early Devonian.

Bamboo-jointed stones began to appear in the Ordovician Period, reached their peak in the Devonian Period, and became extinct at the end of the Devonian Period. Among them, the thin-shelled tower-jointed stones were the most prosperous, and the smooth-shelled stones were the most prosperous.

It is also very important.

The evolution of conodonts reached a peak of development in the Devonian period, a period characterized by the appearance of a large number of platform-type molecules.

The earliest insect fossils were also discovered in the Devonian period.

The Devonian period was a period of rapid development of vertebrates, when fish flourished and various types of fish appeared, so the Devonian period is called the "Age of Fishes".

". The Early Devonian was dominated by jawless fish, while the Middle and Late Devonian armored fish were quite prosperous. They already had primitive jaws, developed paired fins, and crooked tails.

In the Early Devonian, pteridophytes flourished, with a small number of lycophytes, most of which were simple-shaped, small-sized herbs. In the Middle Devonian, pteridophytes flourished, with a small number of lycophytes.

The primitive lycophytes were still dominant, but the primitive lycophytes were more developed, and primitive sphenops and the most primitive true ferns appeared; when the Late Devonian arrived, the naked ferns were on the verge of extinction.

However, the lycophytes continued to flourish, the arthropods and primitive sphenopsids developed, and new true ferns and seed ferns began to appear.

6. [Carboniferous] The Age of Amphibians

The Carboniferous period began about 355 million to 295 million years ago and lasted for 60 million years.

The climate was warm and humid, swamps were everywhere, and large-scale forests appeared on the continent, creating an opportunity for the formation of coal.

Favorable conditions.

The Carboniferous period was also a period of very active crustal movement, so the paleogeography underwent great changes. The climate differentiation phenomenon during this period was also very obvious.

The northern ancient continent was a warm and humid coal-accumulating area, while the Gondwana continent was a cold continental glacial sedimentation environment. Climate zoning leads to the geographical division of animals and plants

formation.

Compared with the Devonian period, the marine invertebrates of the Carboniferous period have undergone significant changes. The shallow seafloor inhabitants are still dominated by corals and brachiopods.

Among the planktonic and swimming animals in the late Carboniferous period, new species of ichthyosaurs appeared, and ammonites continued to flourish. Most trilobites had become extinct by the Carboniferous period, leaving only

Several genera and species.

Insects were first discovered in the Devonian period and further prospered in the Carboniferous period. There are more than 1,300 known insect species in the Carboniferous and Permian periods.

At the beginning of the Early Carboniferous, amphibians flourished, mainly the Stegocephalans (also known as Amphibians).

Teeth), while vertebrae also flourished.

The vegetation in the Early Carboniferous was similar to that in the Late Devonian. Ancient ferns continued to grow, but could only adapt to the coastal lowland environment.

In the next step, in addition to the ferns and lycophytes, the true ferns and seed ferns also began to develop rapidly. Among the gymnosperms, the koda tree is a tall tree.

It has become one of the important materials for coal making.

Claw sea urchin

7. [Permian] Important coal-forming period

The Permian period is the last period of the Paleozoic Era and an important coal-forming period.

250 million years, a total of 45 million years. The crustal movement was relatively active during the Permian period, the relative movement between ancient plates intensified, and many geosynclines around the world were closed.

Folded mountain ranges were gradually formed, and the ancient plates gradually joined to form a united ancient continent (Pan-Continent). The land area was further expanded and the ocean area was reduced.

The changes in the natural geographical environment have promoted important evolutions in the biological world and heralded the arrival of a new era in the history of biological development.

The Permian period was an important period of evolution in the biological world. The main classes of marine invertebrates were still ichthyosaurs, corals, brachiopods and ammonites, but their composition changed dramatically.

There were important changes. Only a few trilobites remained among the arthropods, and gastropods and bivalves had developed in new ways. At the end of the Permian period, tetracorals and plank corals

Corals, anemones, and trilobites all became extinct; the number of brachiopods was greatly reduced, with only a few species remaining.

Vertebrates developed to a new stage in the Permian period. The cartilaginous fish and bony fish developed in a new way, and many

New types of cartilaginous and hard-scaled fish developed rapidly. Amphibians further prospered. Among reptiles, the cup dragons developed in the Permian period; the mesosaurs swam in the rivers.

streams or lakes, represented by the Mesosaurs of Brazil and South Africa; Pelycosaurs were found in the late Carboniferous and early Permian; Therapsids were found in the middle and late Permian and Triassic.

A mammal-like reptile from the Permian Period found throughout the world.

The appearance of the plant world in the Early Permian was similar to that in the Late Permian, still dominated by ferns, lycopods, true ferns, and seed ferns.

Gymnosperms such as Cycas Bennetii, conifers, etc. began to show the appearance of the Mesozoic zone.

Primitive sea urchin, phalarodon (picture)

Due to the changes in the ocean and land caused by the movement of the earth's crust, terrestrial naked ferns evolved from coastal shallow green algae plants began to appear. Ferns have real roots, stems and leaves, and the roots, stems and leaves have conductive tissues and relatively developed mechanical tissues. The plants are tall and cannot be fertilized without water. Most of them live in a humid environment and become primitive lycopods and articulated plants. The evolution from ferns to gymnosperms marks the transition from spore propagation to seed propagation. Gymnosperms reproduce by seeds, which are suitable for living and spreading on land, expanding the living space, forming vast forests on the earth, and providing a favorable living environment for the development of reptiles.

The earliest vertebrates on Earth were ancient fish, which include jawed and jawless fish. Early fish were jawless, including cephalopods and finned fish. The earliest group of jawless fish was the heterosaurids, followed by the earliest jawed spiny fish and placoderms that differentiated from the jawless fish. With upper and lower jaws, spiny fish can not only passively feed on tiny organic matter, but can also actively hunt for larger food. Later, spiny fish developed into bony fish, including lobe-finned fish, lungfish, and ray-finned fish. Placoderms developed into cartilaginous fish, such as sharks and rays, as well as the chimaeras that live in the deep sea.

As cross-finned fish moved to land, they became the earliest type of terrestrial vertebrates, and amphibians began to appear. When vertebrates came to land, they first had to solve the problem of breathing and movement. Cross-finned fish already had the structure of primitive lungs, and their fleshy paired fins could crawl on the ground. The modern amphibians that have survived include salamanders, frogs, etc.

The sauropods that evolved from amphibians are likely the ancestors of reptiles. After a long period of evolution, they developed amniotic eggs that can adapt to arid land environments. Thus, reptiles were born. The development from amphibians laying eggs and fertilizing them in water to reptiles fertilizing and producing amniotic eggs in vivo is a major leap in the history of vertebrate evolution.

Reptiles lay eggs and hatch on land, completely breaking away from the confinement of water and becoming true terrestrial animals. The complexity and diversity of the terrestrial living environment provided a new ecological environment and adaptation direction for the evolution of animals. Primitive reptiles differentiated and developed in various directions, evolving into primitive birds and mammals.

The transition from cold-blooded reptiles to warm-blooded birds was a major leap in the history of vertebrate evolution. The body temperature of warm-blooded animals (birds and mammals) is relatively stable and is not affected by the external temperature, which enhances their adaptability to the climate environment and expands their geographical distribution range.

Angiosperms appeared in the late Early Cretaceous, and quickly multiplied in the Middle and Late Cretaceous. They flourished greatly in the Cenozoic Era, replacing gymnosperms and becoming the most advanced group in the plant kingdom, ushering in the angiosperm era. Angiosperms have more advanced internal structures and perfect reproductive organs than gymnosperms. Because the seeds are covered with pericarp, which helps to protect the seeds, reproduce offspring, and better adapt to terrestrial life, angiosperms are the most advanced group in the plant kingdom. The rapid development and wider geographical distribution of angiosperms provided abundant food resources for the animal kingdom that depended on plants for survival, and promoted the great development of insects, birds, and mammals.

The earliest mammals were differentiated from the mammal-like reptiles of the Triassic period. Entering the Cenozoic Era, due to the separation or convergence of plates, the differentiation of climate, the rapid development and widespread distribution of angiosperms, mammals rapidly differentiated and radiated, and achieved unprecedented development, replacing reptiles and occupying a dominant position on the earth. As a result, the evolution of vertebrates entered a more advanced stage - the mammalian era. The development from the cold temperature and oviparity of reptiles to the homeothermy, viviparity and lactation of mammals, as well as the highly developed nervous system and sensory organs, was a major leap in the history of vertebrate evolution.

The most primitive mammals were mainly insectivores. The ancient ungulates, the Ankylosaurs, also evolved from the primitive insectivores. They are the most primitive branch in the process of development from insectivores to herbivores. They are the common ancestors of most later ungulates, including horses, tapirs, rhinos and odd-toed ungulates, and pigs, cattle, sheep and other even-toed ungulates. Carnivores are divided into ancient carnivores, new carnivores and pinnipeds. At the end of the Eocene, new carnivores flourished, such as the living cats, tigers, dogs, etc. Soon after the appearance of new carnivores, marine pinnipeds (sea lions, seals, walruses) began to appear.

Even-toed ungulates began to appear in the Eocene, and developed greatly through the Oligocene, Miocene and Pliocene, from the Pleistocene to the present. Even-toed ungulates are divided into suids, camelids and ruminants. Suids appeared in the early Eocene, and they were all small even-toed ungulates, such as the Eocene biconodont and the Gobisuid. From the Oligocene to the Pliocene, their body size became larger. In the Pleistocene, pigs similar to modern wild boars appeared. Ruminants include mouse deer, deer, giraffes, cattle, sheep, antelopes, etc.

Primates may have evolved from a branch of insectivores, about 70 million years ago, at the end of the Cretaceous period of the Mesozoic Era, or at the beginning of the Paleocene Epoch of the Tertiary Period of the Cenozoic Era. In North America and Europe, fossils with morphology between insectivores and primates were found in the Paleocene and subsequent Eocene strata, which are very similar to the common tree shrews alive today. This animal has many characteristics close to primates, such as round eye sockets, wrinkles behind the eye sockets, and the two eyes are beginning to be parallel; the brain is larger, and the olfactory lobe is smaller; the first finger (toe) is slightly separated from the other four fingers (toes), and the claws can be extended to grab branches, etc. After a long period of interaction with the environment, the characteristics of primates gradually emerge.

Biological evolution is actually a history of the interaction between organisms and the environment. In this historical process, different stages have different protagonists, who reach their peak and then gradually decline, and then new protagonists come on the historical stage. This is the result of the continuous renewal of the ecological environment and the result directed by the laws of cosmic material evolution.

In the process of biological evolution, the environment in which organisms live can be divided into two types: one environment is the natural climate and geography of the earth. The climate and geography of different places on the earth are different. Each region and area has its own environmental characteristics, which have different effects on the survival form of organisms. The other is the biological environment, which is the relationship between different species living on the earth and different individuals of the same species, that is, the interdependence and competition between various organisms. This relationship has a more complex and profound effect and influence on the survival form of organisms.

The natural ecological system is a more complex system than the general material action system. It is composed of non-living things, microorganisms, plants, and animals. Different species have different properties, different living habits, and different ways of reproduction. They form a food chain and a behavioral chain based on it. Such a survival chain promotes the evolution of species. In this multi-species biological system, different life forms form certain relationships with each other and are conditions for each other's existence and development.

Biological evolution is a process of gradual advancement of multiple aspects of evolution. Biological evolution is manifested in the evolution of various biological functions. The generation and evolution of various biological structures correspond to the forces exerted by the environment, including the biological ability to move, hearing, vision, smell, intelligence, etc. Various functions gradually develop and improve according to the needs of survival. With the continuous interaction between organisms and the environment, the gradual accumulation of subtle changes in the body, after a long period of evolution, organisms have undergone great changes from their inner essence to their external form.

From the perspective of the survival process, every life has to go through the process of birth, growth, maturity and aging. This is the process of interaction between the organism and the environment. Every life will be marked by the times. In the process of interaction between the organism and various existences in the environment, as a force structure, the survival form of the organism will change due to the interaction with the environment, and such changes will be reflected in the internal organizational structure and genetic structure of the organism. On the surface, biological activities revolve around survival and reproduction, but they contain the trend of change and development of the material form in the universe.

On Earth, animals, plants, and microorganisms are constantly evolving. At the same time, evolution includes the biological structure, the relationship between individuals and species, and the evolution of the entire system. In the process of life development, the existence of each life is meaningful. It does not exist in isolation, but will have an impact on the existence of other lives. The role of an individual seems insignificant, but the existence of many tiny lives determines the evolution of life.

An ecosystem is a system of biological interaction, where different organisms depend on each other, compete with each other, and cycle, regenerate, and develop. For organisms in a constantly changing relationship, it is necessary for them to adjust their biological structure and function to adapt their own survival form to the environment. In the process of biological evolution, old life forms are constantly replaced by new ones, and life on Earth continues to thrive and develops more and more perfectly.