https://www.biorxiv.org/content/10.1101/2022.12.09.519446v2
Science news article: https://www.science.org/content/article/how-anteaters-lost-their-teeth
Armadillos, sloths. and anteaters are related and have issues with their teeth. It looks like the lifestyle of the ancestor of the three is responsible for the degeneration of their teeth. Armadillos may have separated from the sloth-anteater branch before they started losing
their teeth. It turns out that the two lineages lost their tooth genes
in a different order. The common ancestor of sloths and anteaters lost several enamel genes before sloths diverged from anteaters. Anteaters
went on to lose several more genes for teeth and became toothless, but
sloths changed their diet and had to compensate for the loss of enamel
by having their teeth keep growing. The armadillo lineage shows a
different order of gene loss.
This paper used psuedogene sequences for the analysis. In this case
these pseudogenes are the gene "fossils" left in the genome when
inactivating mutations occur in a gene and knock it out. The gene
sequences is still recognizable but now subsequent mutations can freely
occur in what is left of the gene because the gene is already nonfunctional.
RonO <rokimoto@cox.net> wrote:
https://www.biorxiv.org/content/10.1101/2022.12.09.519446v2Thank you for posting this Ron.
Science news article:
https://www.science.org/content/article/how-anteaters-lost-their-teeth
Armadillos, sloths. and anteaters are related and have issues with their
teeth. It looks like the lifestyle of the ancestor of the three is
responsible for the degeneration of their teeth. Armadillos may have
separated from the sloth-anteater branch before they started losing
their teeth. It turns out that the two lineages lost their tooth genes
in a different order. The common ancestor of sloths and anteaters lost
several enamel genes before sloths diverged from anteaters. Anteaters
went on to lose several more genes for teeth and became toothless, but
sloths changed their diet and had to compensate for the loss of enamel
by having their teeth keep growing. The armadillo lineage shows a
different order of gene loss.
This paper used psuedogene sequences for the analysis. In this case
these pseudogenes are the gene "fossils" left in the genome when
inactivating mutations occur in a gene and knock it out. The gene
sequences is still recognizable but now subsequent mutations can freely
occur in what is left of the gene because the gene is already nonfunctional. >>
On Tue, 08 Aug 2023 12:22:30 +0000, the following appeared
in talk.origins, posted by *Hemidactylus*
<ecphoric@allspamis.invalid>:
RonO <rokimoto@cox.net> wrote:Ditto. Jus a comment, though: This sounds to me like the
https://www.biorxiv.org/content/10.1101/2022.12.09.519446v2Thank you for posting this Ron.
Science news article:
https://www.science.org/content/article/how-anteaters-lost-their-teeth
Armadillos, sloths. and anteaters are related and have issues with their >>> teeth. It looks like the lifestyle of the ancestor of the three is
responsible for the degeneration of their teeth. Armadillos may have
separated from the sloth-anteater branch before they started losing
their teeth. It turns out that the two lineages lost their tooth genes
in a different order. The common ancestor of sloths and anteaters lost
several enamel genes before sloths diverged from anteaters. Anteaters
went on to lose several more genes for teeth and became toothless, but
sloths changed their diet and had to compensate for the loss of enamel
by having their teeth keep growing. The armadillo lineage shows a
different order of gene loss.
This paper used psuedogene sequences for the analysis. In this case
these pseudogenes are the gene "fossils" left in the genome when
inactivating mutations occur in a gene and knock it out. The gene
sequences is still recognizable but now subsequent mutations can freely
occur in what is left of the gene because the gene is already nonfunctional.
classic detrimental mutation, and it's remarkable to me that
the species survived it; teeth are pretty significant, and
barring the development of a replacement, such as a bill,
would seem to be fairly necessary for species survival.
On 8/8/2023 11:03 AM, Bob Casanova wrote:
On Tue, 08 Aug 2023 12:22:30 +0000, the following appeared
in talk.origins, posted by *Hemidactylus*
<ecphoric@allspamis.invalid>:
RonO <rokimoto@cox.net> wrote:Ditto. Jus a comment, though: This sounds to me like the
https://www.biorxiv.org/content/10.1101/2022.12.09.519446v2Thank you for posting this Ron.
Science news article:
https://www.science.org/content/article/how-anteaters-lost-their-teeth >>>>
Armadillos, sloths. and anteaters are related and have issues with their >>>> teeth. It looks like the lifestyle of the ancestor of the three is
responsible for the degeneration of their teeth. Armadillos may have
separated from the sloth-anteater branch before they started losing
their teeth. It turns out that the two lineages lost their tooth genes >>>> in a different order. The common ancestor of sloths and anteaters lost >>>> several enamel genes before sloths diverged from anteaters. Anteaters >>>> went on to lose several more genes for teeth and became toothless, but >>>> sloths changed their diet and had to compensate for the loss of enamel >>>> by having their teeth keep growing. The armadillo lineage shows a
different order of gene loss.
This paper used psuedogene sequences for the analysis. In this case
these pseudogenes are the gene "fossils" left in the genome when
inactivating mutations occur in a gene and knock it out. The gene
sequences is still recognizable but now subsequent mutations can freely >>>> occur in what is left of the gene because the gene is already nonfunctional.
classic detrimental mutation, and it's remarkable to me that
the species survived it; teeth are pretty significant, and
barring the development of a replacement, such as a bill,
would seem to be fairly necessary for species survival.
They think that the ancestor of armadillos, sloths and anteaters ate
worms and insects, so they didn't need teeth. The armadillo lineage and
the sloth-anteater lineage continued to eat bugs and worms and their
teeth started to degenerate for lack of selection to maintain them. The >sloth lineage changed it's diet, but was stuck with the degenerate
teeth, so it evolved teeth without enamel that just kept growing so they >didn't have to worry about wearing them out. Anteaters lost even more
toothy genes and became toothless.
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