Differences between invertebrate and invertebrate early embryonic development patterns

Vertebrates are one of the invertebrates that evolved from.

To be precise, it is the group of posterior animals in the invertebrates that gave birth to vertebrates (Among the posterior animals, there are still lower and closely related vertebrate echinoderms (such as starfish, sea cucumbers, etc.), which are still invertebrates

Other invertebrates, on the other hand, have an almost exact parallel relationship with vertebrates in their evolutionary history

The vertebrates here evolved from early chordates to various fish, one of which began to try to evolve to the land to evolve amphibians, and then from amphibians to early reptiles, reptiles opened several branches, one of which is dinosaurs and birds, and the other is mammals. (There are also snakes, turtles, lizards, crocodiles, etc., which are actually parallel to birds and mammals.) They have gone from aquatic to landed life as a whole (with some re-aquatic).

On the other hand, invertebrates, the most prosperous and successful are all kinds of arthropods and molluscs, they have also changed from aquatic to terrestrial in different geological and historical periods, from simple to complex (among them, the landing process of scorpions, spiders and insects in arthropods is not the same, not to mention the mollusks, how those snails land, are parallel and independent of each other...... process).）

Let me be more detailed with you:

From the perspective of the process and law of evolution, vertebrates should have evolved from invertebrates, and there must have been many intermediate types of stages in between.

Since invertebrates are not hard.

bones, so only from the comparative anatomy and comparative embryological aspects of the material to find clues to evolution. Vertebrates have a notochord during ontogeny

Pharyngeal cleft parotid and dorsal nerve canal, hence the ridge.

Vertebrates share a common ancestor, the protocephalic class, which is presumed to have occurred in the Cambrian period. The primitive headless class evolved into the primitive head class with a brain, senses, and skull at the front, that is, it became the ancestor of vertebrates.

Whereas caudal chordates and cephalic chordates may be the two proto-headless.

specialized branches.

The evolution of vertebrates can be divided into three stages:

evolution in water;

From water to land.

the evolution of amphibians and reptiles; If you think about the evolution of birds and mammals, vertebrates are gone, and they will slowly evolve again after hundreds of thousands of years, while invertebrates are gone, and the foundation of life will be broken.

It mainly goes through five stages: fertilization and fertilization of the egg, cleavage, formation of blastocysts, formation of gastrulation, formation of mesoderm and body cavity.

Unicellular animals – the ancestors of sponges (i.e., porous animals) – coelenterate and ctenophores – flattened animals, and then there are two main branches:

1. The ancestor of mollusks - annelids - arthropods 2. The ancestors of hairy jaws - the ancestors of echinoderms - the ancestors of hemichordates - chordates.

The above is not conclusive. As for the upstairs, it's not that I said they're all messed up.

Inside chordates, the ancestors of cephalic and caudal chordates - vertebrates (fish-amphibian-crawling, then two branches: birds or dinosaurs including birds, mammals).

Answer]: The development of invertebrate embryos generally goes through several stages: the formation of blastocysts, gastrulations, mesoderm and body cavity, the differentiation of the germ layer and the formation of slippery organs.