Question

Mammals in general provide parental care for their young. This seems to imply that parents should be able to recognize their own young. Yet, for some mammals such as the wild mouse (Mus musculus), pup recognition by dams (mothers) does not occur (sires are not involved in parental care in mice). Dams will care for any pup that is available. In the lab, if a dam is placed in a cage with two or more litters of pups, she will gather them into one giant pile of pups and attempt to nurse, groom and care for all of them. An entire genetic litter can also be replaced by a new litter of entirely unrelated pups and the dam will adopt and care for them as if they were her own. In meadow voles (Microtus pennsylvanicus), another common prairie rodent, pup recognition apparently does not occur until 7-9 days have passed. Prior to that time, dams will adopt any young that appear in their nest. Under what evolutionary conditions might non-recognition of offspring develop? Under what evolutionary conditions should recognition of young develop?

Answer 1

Note: This response is in UK English, please paste the response to MS Word and you should be able to spot discrepancies easily. You may elaborate the answer based on personal views or your classwork if necessary.

(Answer) The purpose of an evolutionary trait is for a particular species to survive changing and difficult conditions by adapting to them. This makes a species amenable to its surroundings by swaying in the direction of the wind, so to speak.

Animals such as the wild mouse and even meadow voles are probably evolutionarily wired to let the species survive at all costs. Sometimes the cost to pay is that the young ones they nurse are not always their own but is still a part of the same species. In a way, they have evolutionarily adapted to “equal rights to survival.”

In order to let the species survive, these mothers nurse and care for just about any child of their species. This is probably brought about by the harsh wild environment that this delicate creature might have had to battle to survive throughout history. Such conditions would have let to the species taking whatever steps necessary to survive, and that includes caring for any child, even it isn’t their own.