they dont live long enough for tumors in the wild that, at least not in the wild. the domesticated rats are all inbred mostly thats why they get tumors. in the wild rats die from predators and infections more often. another plus is they dont live long enough to spread rabies if they get infected.
marsupials also have a much lower body temperature than placental mammals.
bats is very mysterious, i think its due to thier long evolutionary history compared to most mammals, allow them to co-exist with the pathogens. they suddenly came into the picture right before the cretacaeuous ended, we dont even know what bats evolved from. funny thing one of the clues is “bat bugs” which are predecessors to bed bugs( and they can infect humans). other unusual mammals are solenedons/nosphenthes lineages.
There is usually a major heath issue associate with short lived species. For example, rats usually die riddled with tumors.
they dont live long enough for tumors in the wild that, at least not in the wild. the domesticated rats are all inbred mostly thats why they get tumors. in the wild rats die from predators and infections more often. another plus is they dont live long enough to spread rabies if they get infected.
marsupials also have a much lower body temperature than placental mammals.
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bats is very mysterious, i think its due to thier long evolutionary history compared to most mammals, allow them to co-exist with the pathogens. they suddenly came into the picture right before the cretacaeuous ended, we dont even know what bats evolved from. funny thing one of the clues is “bat bugs” which are predecessors to bed bugs( and they can infect humans). other unusual mammals are solenedons/nosphenthes lineages.