Jointed limbs are an important development because they allow animals, including humans, to move. Without joints we would be comprised of an immobile skeleton.
The Cambrian period was when animals evolved hard exoskeletons, probably in response to pressures from predatory animals.
I believe that it's because patterns of development differ between species.
Modern plants and animals resemble fossils found in the same area.
zoology
Perhaps the most significant evolutionary trend among the metazoan invertebrate phyla is that of cephalization. This term refers to the development of a head, containing a brain. Another process called segmentation allowed animals to develop distinct body parts, such as legs, wings and feelers.
development of lungs
Taxonomy, spiders and insects they have jointed legs
arthropods.
yes
They provided a greater range of motion, which improved survival by allowing fishes to catch more prey and avoid predators. They enabled animals to increase the accuracy and speed of their movements.
arthropods
Clues can be found out about the evolutionary relationships of animals by studying fossil records.
animals within the phylum Arthropoda
The Cambrian period was when animals evolved hard exoskeletons, probably in response to pressures from predatory animals.
I believe it is Carbon.
The behavior of animals and humans can be studied with an evolutionary lens. This allows scientists to determine why certain behaviors were beneficial in evolutionary terms.
Actually, no animal on the planet has joined limbs unless they are deformed.