8Evolution Vertebrates are the most highly evolved organisms. Their bodies are divided into different systems to accomplish various tasks.For example all vertebrates have a nervous system, reproductive system, circulatory system, digestive system, and respiratory system.Of course, they have eukaroytic cells.
9The first vertebrate arose 500 m. y. a The first vertebrate arose 500 m.y.a. called the myllokunmingia, or type of jawless fish.
10HomeostasisVertebrates use their different systems to maintain internal balance.For example, in maintaining body temperature, vertebrates use a variety of methods.Animals that have a low metabolic rate and don’t generate much heat are called poikilotherms. They must pick up heat from the environment, or avoid it when it’s too hot.
11Lizards and snakes are poikilotherms and must lie in the sun to warm up their muscles in order to move.Homeotherms have a high metabolic rate which generates a significant amount of internal heat. Therefore, they do not necessarily have to move to colder or warmer areas to maintain a constant internal temperature.
12Energy Vertebrates are heterotrophic. Their diet is widely varied - they can be carnivorous, herbivorous, ominivorous or detritivores.All vertebrates have a well developed digestive system to help them obtain and use energy.
13Most vertebrates have special adaptations that help them with the digestive/eating process. For example, birds have a crop.This is an enlarged area of the esophagus where food can be stored and moistened before it goes into the stomach. In some species the crop stores regurgitated food for their babies.
14ReproductionExcept for rare exceptions, vertebrates have two separate genders within a species.Oviparous vertebrates lay eggs.Ovoviparous vertebrates have eggs, but they develop and hatch internally.Vivaparous vertebrates have embryos that are nourished by the mother’s body.
15EcologyEven though a very small percent of living organisms are vertebrates, they tend to dominate due to their size and mobility.Vertebrates live in almost every part of the world. Can you think of a place where they don’t live???
16Each vertebrate plays an important role in a certain biome. For example, many birds have a vital role in the lives of plants.Hummingbirds help pollinate flowers.Fruit eating birds help disperse seeds.