Morris, Henry M., 1974. Scientific Creationism, Green Forest, AR: Master Books, p. 82
No fossils have been found transitional between invertebrates and vertebrates.
Evolutionary Transition of Promoter and Gene Body DNA Methylation across Invertebrate-Vertebrate Boundary 1
Genomes of invertebrates and vertebrates exhibit highly divergent patterns of DNA methylation. Invertebrate genomes tend to be sparsely methylated, and DNA methylation is mostly targeted to a subset of transcription units (gene bodies). In a drastic contrast, vertebrate genomes are generally globally and heavily methylated, punctuated by the limited local hypo-methylation of putative regulatory regions such as promoters. These genomic differences also translate into functional differences in DNA methylation and gene regulation. While promoter DNA methylation is an important regulatory component of vertebrate gene expression, its role in invertebrate gene regulation has been little explored. Instead, gene body DNA methylation is associated with expression of invertebrate genes. However, the evolutionary steps leading to the differentiation of invertebrate and vertebrate genomic DNA methylation remain unresolved. Here we analyzed experimentally determined DNA methylation maps of several species across the invertebrate-vertebrate boundary, to elucidate how vertebrate gene methylation has evolved. We show that, in contrast to the prevailing idea, a substantial number of promoters in an invertebrate basal chordate Ciona intestinalis are methylated. Moreover, gene expression data indicate significant, epigenomic context-dependent associations between promoter methylation and expression in C. intestinalis. However, there is no evidence that promoter methylation in invertebrate chordate has been evolutionarily maintained across the invertebrate-vertebrate boundary. Rather, body-methylated invertebrate genes preferentially obtain hypo-methylated promoters among vertebrates, regardless of their promoter methylation status. Conversely, promoter methylation is preferentially found in lineage- and tissue-specific vertebrate genes. These results provide important insights into the evolutionary origin of epigenetic regulation of vertebrate gene expression.
Evolution's Biggest Hurdles 2
The theory of evolution has numerous problems, some of which are absolutely enormous and for which no adequate solution has even been proposed. The biggest problem comes right at the beginning with the supposedly spontaneous generation of life from non-life. Neo-Darwinian scientists admit this, recognizing that proposed evolutionary scenarios do not model reasonable conditions on earth, and could not have produced anything like the complex life we see all around us--even single-celled life.
The second-biggest problem involves the development of complex invertebrates, animals without a backbone, from single-celled life. How did this transition occur? A robust fossil record of one-celled life has now been found, and of course a truly abundant record of marine invertebrates can be discovered everywhere, from clams to sponges to jellyfish to starfish, etc. The "explosion" of life in the Cambrian system of strata continues to baffle evolutionists, for there is no record showing a transition from tiny single-celled life to complex invertebrates. There are innumerable fossils of invertebrate ocean bottom life, even those with no hard outer shell, but no ancestors of these invertebrates have been identified.
A third huge problem lies in the next step required by evolution. Fish, thought to be the first vertebrates, must have evolved from invertebrates, but again there is no record of this transition. "How this earliest chordate stock |i.e., early vertebrates| evolved, what stages of development it went through to eventually give rise to truly fishlike creatures, we do not know."1 Over the years nearly every invertebrate has been proposed as the ancestor, but each suggestion has only been in vogue for a time. As Dr. Duane Gish--former Senior Vice President at ICR and a well-known creation scientist--likes to say, if evolution can't derive either invertebrates from single-celled life, or vertebrate fish from invertebrates, it is "dead in the water."
Without the assumption of evolution, without the neo-Darwinian scientist's "certain knowledge" that vertebrates evolved from invertebrates, this flimsy link would not merit such attention. How much more scientific it is to recognize the God-designed diversity in creation, and not attribute all living things to a hypothetical common ancestor.