This is true of old bird study skins which often used arsenic to prevent bugs from eating them, but modern study skins don't use any harsh chemicals in the preservation process - just cotton and sunlight. Sometimes dawn dish soap will be used if the skin is particularly dirty.
Also even historical bird skins don't tend to have large amounts of arsenic on the foot pads which is where DNA is often sampled from due to its thickness and its remarkably successful compared to other taxa. Though the addition of arsenic does inhibit PCR success,its not found at a particularly high volume on the feet of historical study skins.
Here's a link to one reference, but I'm also just speaking from experience preparing study skins and picking up info from there.
This isn't to contradict the fact that there is less dodo DNA than mammoth - but preserved bird skins are some of the easiest to extract DNA from, compared to ethanol preserved specimens (common for herps and insects) and mammalian taxidermy.
I think your point from another comment about how mammoths were essentially frozen is the primary reason that there is more usable DNA.
cowbirdy t1_iwbhtjp wrote
Reply to comment by deadmeatsandwich in How do we have more woolly mammoth DNA than dodo DNA if woolly mammoths died off thousands of years ago and dodos only died off a few hundred? by Memer9456
This is true of old bird study skins which often used arsenic to prevent bugs from eating them, but modern study skins don't use any harsh chemicals in the preservation process - just cotton and sunlight. Sometimes dawn dish soap will be used if the skin is particularly dirty.
Also even historical bird skins don't tend to have large amounts of arsenic on the foot pads which is where DNA is often sampled from due to its thickness and its remarkably successful compared to other taxa. Though the addition of arsenic does inhibit PCR success,its not found at a particularly high volume on the feet of historical study skins.
Here's a link to one reference, but I'm also just speaking from experience preparing study skins and picking up info from there.
This isn't to contradict the fact that there is less dodo DNA than mammoth - but preserved bird skins are some of the easiest to extract DNA from, compared to ethanol preserved specimens (common for herps and insects) and mammalian taxidermy.
I think your point from another comment about how mammoths were essentially frozen is the primary reason that there is more usable DNA.