Ken Ham recently tweeted about a baby born with a “tail.” I agree with his assessment that these are not cases of bony tails, homologous to tails in almost all vertebrate species, but then I wondered, can young-earth creationists be sure that Adam and Eve did not have true bony tails as adults? After all, Ken Ham wasn’t there to see Adam and Eve and record their appearance and we have no biblical record that reveals if they had tails or not as a created kind. We do know from present day observations that all vertebrates, including humans, have tails at some point during their life and more than 99% of all vertebrate animal species have bony tails as adults so it isn’t crazy to ask the question: could the rare exceptions without adult tails simply be examples of species that once had tails but then lost them?
That led me to do a bit more reading about what we know about the genes behind tail formation and prompted me to record the YouTube video linked below.
Not long ago in my genetics course I briefly described a recent manuscript implicating mutations in a gene involved in influencing early development to primate species that lack a tail. I took another look at that manuscript and here I take a deep dive into the molecular genetics of the TBXT gene to explain the significance of this discovery and ask how young-earth creationists could potentially use it to propose that Adam initially had a bony tail and his descendants lost it as a result of alterations to their genomes via a mechanism they frequently employ in their literature called post-fall genetic entropy.
Tail or no tail originally, the mutations to the genome that may lead to the lack of tail development in adult apes is a lesson in how mobile genetic elements in genomes can dramatically affect how genes are regulated resulting in significant changes in phenotype (appearance of traits). In brief, in ape species which all lack bony tails as adults their genomes are all observed to contain an extra copy of a transposable element (a jumping gene) inserted inside a very important early development gene. I discuss how the addition of this approximately 300 bp piece of DNA to this gene alters the expression of the gene which is hypothesized to result in the lass of tails in adults. The authors of this research provide support for their hypothesis by altering the genome of a mouse mimicking the effects of this sequence in humans and showing that mice with this human-like gene expression lack or have very short tails. They also edit human cell lines showing that the gene expression is changed in the way that they predict.
Given these observations of the human TBXT gene young-earth creationists could propose that Adam and Eve were created without this inserted transposon in their genes allowing them to maintain full function of the originally created gene and then post-fall mutations inserted this new genetic element in the gene disrupting its function resulting in descendants that lost their tails. Alternatively, they would need to propose that God used the full-length gene used by all vertebrates resulting in mature tails and then added this extra bit to humans which blocks the use of part of the gene, which still maintaining the whole gene in the genome, resulting in the loss of the tail during embryonic development.
Paper discussed in the video: Xia, Bo, Weimin Zhang, Aleksandra Wudzinska, Emily Huang, Ran Brosh, Maayan Pour, Alexander Miller et al. “The genetic basis of tail-loss evolution in humans and apes.” bioRxiv (2021).https://www.biorxiv.org/content/10.1101/2021.09.14.460388v1
Ken Ham’s blog post about babies born with human tails: https://answersingenesis.org/human-body/vestigial-organs/baby-born-human-tail/
I wonder; were whales created on Day 5 with broken smell genes, or with perfect smell genes that broke post-Fall? Indeed, how do creationists even attempt to explain broken genes, or (as in this case) suppressed genes in general?
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One would have to wonder what would be so perfect about smell genes that are not needed under water. I’ve not seen a YEC seriously reflect on the broken genes in whales and map out any scenarios that would be consistent with a YEC worldview.
Are you sure that they are broken?
Research on non-coding DNA (including for example pseudogenes) suggests function.
Evolutionists do try to say tailly babys show the old days. in faxct its just a probability curve on errors in the spine over extending. We never had av tail for the reason tails are used. the fetus does not have a tail but instead something useful in its growth. its not tail like real tails.
Evolutionists do a poor job on human things like this in trying to show we had a tail past.
We are not invertebrates. These classifications are human myths .
Humans don’t have tails. they have a trait in untero thats for a real prpose.
This isn’t even interesting babble. At least do a bit of research before just randomly typing in words. Seriously, this makes little to no sense.
It makes sense. FIRST i’m saying your wrong that evolutionists don’t use baby tails to make a pro evolution point. tHey do and other things. SECOND. i’m saying its just a probability curve of birth errors , in this case, entended spine. I mean if we never had tails it still would be we would have babys with these ‘tails” Its just the odds on errors in how our bodies are developed.
THIRD. I say we are not invertebrates and saying we have a tail in uteral is wrong. Its not a tail because of a extended part of the body in a weird time of development. YES evolutiuonists also use that to say AHA look at our past!