The reason acorn worms are lumped into the base of the vertebrate evolutionary tree is because they have a section of their foregut called a stomochord that was previously thought to be related to the notochord of the chordates. 2,3 The acorn worm, a creature also still living today in our world’s oceans, is a hemichordate. The hemichordate, another creature typically lumped into the first evolutionary branch with sea squirts, is entirely unrelated to either sea squirts or fish. An evolutionary transition of that magnitude would require an extensive amount of new genetic information and many novel innate cellular features. There is absolutely no evidence at any level that the chordate-containing larval stage of this creature decided to break free from its internal programming and somehow evolve into a fish. The entire developmental process of this creature in all its complexity is exquisitely programmed by the innate genetic blueprint and cellular systems the Creator engineered into it. 2 The larva attaches itself to a rock and then undergoes an extraordinary metamorphosis into the radically different structure of the stationary adult animal. The main reason evolutionists like to imagine the sea squirt as a vertebrate ancestor is that its larval stage comprises a free-swimming creature that has a mouth, a nerve cord, and a tail. It often has translucent skin and two siphons (or openings) at its top for interfacing with the ocean water to acquire food and resources. The adult form of the sea squirt is a stationary bag-shaped creature (Figure 1) that typically attaches to ocean rocks around the world. Vertebrates are a sub-group of the chordates. Technically, sea squirts are called tunicates, and they represent a marine invertebrate that is part of the phylum Chordata, a group of creatures that includes all animals with dorsal nerve cords or notochords. Even so, paleontologists think they have found evidence of them at the base of the Cambrian rock layers (or slightly before), which would place them smack dab in the Cambrian Explosion where so many complex forms of animal life first appeared suddenly with no evolutionary precursors. While sea squirts are common ocean creatures, their presence in the fossil record has been difficult to determine because they are soft-bodied and don’t fossilize easily. Your First Vertebrate Ancestor: The Sea Squirt?Īccording to the grand evolutionary story, the first proto-vertebrate was a sea squirt, 2 a sea creature that is still alive today. In other words, there is no time or space for evolution to occur since vertebrates show up fully formed at the beginning of the fossiliferous rock record sequence. The problem with identifying a proto-vertebrate ancestor is that vertebrate fish-like creatures appear in the lowest levels of the Cambrian strata, the sedimentary rock layers where complex forms of animals make their first appearances. The rest of animal life is known as invertebrates, which have no vertebral columns (backbones). Overall, vertebrates comprise only about 5% of all known animal species. Living vertebrates exhibit a huge range in size, from a miniature frog found in Papua New Guinea that is only about a quarter of an inch long to the massive blue whale, which is over 100 feet long. Vertebrates include fishes, amphibians, reptiles, birds, and mammals. This glaring gap in the fossil record is just one more example highlighting the lack of evidence for molecules-to-man evolutionary theory. For all practical purposes, no transitional form has been found that links invertebrates like soft-bodied creatures and arthropods (creatures with a hard exoskeleton) to vertebrates. 1 But equally problematic is how complex creatures with backbones (vertebrates) could have possibly evolved. One of the greatest problems for evolutionists is the sudden appearance of complex animal life with no evolutionary precursors, as seen in the Cambrian Explosion.
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