Living ‘Dinosaur Kin’ Has Genes that Defy Evolution
It lived with its fellow reptiles, the dinosaurs. And it stalks the earth today. What do its genes show?
We’re speaking of the tuatara – a rare reptile that survives on a few offshore islands of New Zealand. This endangered species is a “living fossil” – a remnant of a large group of reptiles that once walked with dinosaurs.
The animal’s natural history is described in evolutionary terms this week in Nature:
The tuatara (Sphenodon punctatus)—the only living member of the reptilian order Rhynchocephalia (Sphenodontia), once widespread across Gondwana—is an iconic species that is endemic to New Zealand. A key link to the now-extinct stem reptiles (from which dinosaurs, modern reptiles, birds and mammals evolved), the tuatara provides key insights into the ancestral amniotes.
If it “evolved” though, its genes are not showing a clear pattern of it.
Here we analyse the genome of the tuatara, which—at approximately 5 Gb—is among the largest of the vertebrate genomes yet assembled. Our analyses of this genome, along with comparisons with other vertebrate genomes, reinforce the uniqueness of the tuatara….
Why would such an early animal, said to have “diverged from snakes and lizards” 250 million Darwin Years ago, have a genome that is 67% larger than the human genome? Why would it be more robust than we are? Northern Arizona University says,
One area of particular interest is to understand how tuataras, which can live to be more than 100 years old, achieve such longevity. Examining some of the genes implicated in protecting the body from the ravages of age found that tuatara have more of these genes than any other vertebrate species thus far examined, including humans.
This amazing animal shows no sign of evolution over much longer periods of time, during which Darwinians believe that all the mammals and birds diversified.
But the genome, and the tuatara itself, has so many other unique features all on its own. For one, scientists have found tuatara fossils dating back 150 million years, and they look exactly the same as the animals today.
The tuatara genome has stayed relatively stable for an “enormous amount of time,” says Phys.org:
With no close relatives, the position of tuatara on the tree of life has long been contentious. The research places tuatara firmly in the branch shared with lizards and snakes, but they appear to have split off and been their own species for around 250 million years—an enormous amount of time given primates only originated around 65 million years ago, and hominids, from which humans descend, originated approximately six million years ago.
And yet the genome also shows sudden jumps must have occurred in amniotes (animals that suspend the embryo in fluid during development). Nature seems to argue that evolution is slow except when it is fast:
Our phylogenetic studies provide insights into the timing and speed of amniote evolution, including evidence of punctuated genome evolution across this phylogeny. We also find that, in contrast to previous suggestions that the evolutionary rate for tuatara is exceptionally fast, it is the slowest-evolving lepidosaur yet analysed.
Here come the theory rescue devices:
This lineage also shows moderate rates of molecular evolution, with instances of punctuated evolution. Our genome sequence analysis identifies expansions of proteins, non-protein-coding RNA families and repeat elements, the latter of which show an amalgam of reptilian and mammalian features.
The original paper is open for access to anyone:
Gemmell et al., “The tuatara genome reveals ancient features of amniote evolution,” Nature 05 August 2020, https://doi.org/10.1038/s41586-020-2561-9.
How does this confusing genome and basically-unchanged body plan “shed light on evolution”? It doesn’t. But since Big Science is in the business of lying for Darwin (7 Aug 2020), evolutionists can say with impunity that the tuatara genome “will aid human understanding of the evolution of the amniotes, a group that includes birds, reptiles and mammals.” Call back when you gain the understanding.