Animal Mothers


A person could easily fill hours of airtime talking about bizarre mating habits of animals from the white spotted pufferfish that draws intricate patterns in the Sandy Ocean floor to attract a mate to the spotted hyena females. WHOSE PSEUDO PENIS which is sometimes larger than the males actual penis is also their birth canal note? Today we're going to focus on the latter two thirds of the process just station or incubation and firth even limiting the topic. There's still a lot. I won't don't get to like how certain reptiles determine the sex of their offspring with the exact temperature in their nests. The station period of animals animals is a matter of scale. The larger an animal is the longer it takes to make a new one despite the resources of the mother being large as well if all the dimensions Shinzo a given animal were doubled. That animal would now have eight times the fall you owing to the square cube rule and hence eight times the wheat of before four but the thickness of the umbilical cord through which all of the growth nutrients flow will only be four times as large so all else being equal it. It would take twice as long for the necessary nutrients to go through if you WANNA get super math nerdy about it and you're welcome to the volume and therefore wait of an animal is proportionate to the cube of the scale Cisco is proportionate to the cube root of the weight of the animal. I read it but I don't understand it. We can scale back on the maths a bit by looking at examples. Humans have station period forty weeks one week short of nine months while humans best friend has the station period of two months. For small animals like rabbits. The period is about one month and for mice about three weeks. The metal for shortest shortest station of a North American mammal goes to the possum which finishes pregnancy soup to nuts in under two weeks. This may have less to do with their size than the fact that their average life span is only about three years so replacements are needed constantly. Elephants are pregnant for a long time like really really long ninety five weeks in fact almost two years. This marathon baby building is one reason that female elephants elephants usually don't have more than four cavs in their whole lifetime. Who's got the time? A giraffe needs almost fifteen months to form. It's one hundred fifty pound founder. Sixty eight kilo baby which starts life off with a bang draft skipworth standing up so it is during air for babies to fall six feet or or two meters to the ground in the process of being worn there are exceptions to are easy to follow. Big babies means long pregnancy guidelines. Of course I one hundred injured and ten pound or fifty kilo. Hippo is ready to debut and only eight months even faster than a seven pound human baby. Black bears are pregnant for thirty weeks but they're cubs only weigh about one pound or half a kilo. One thing that this list of station periods can't take into account are pregnant pauses causes by which I mean pausing pregnancies. That's right some animals have the ability to say you know what now is not a super great time for let me to have babies. Let me just hold the embryo. And Its tracks and turn my uterus into Sifi stasis chamber while I wait for conditions to improve since it was discovered discovered in the eighteen fifties more than one hundred and thirty species of mammal have been found to have this ability. The pause called Dia pause conveniently can last anywhere between a couple of days and up to a year in most species. This happens when the embryo is still a tiny ball of less than one hundred cells. Does that has yet to attached to the uterus. Pausing pregnancy isn't the sole domain of any one class or family. It's found in certain kinds of bats bears Seals rodents deers and armadillos among others. More than a third of the species that take either during the station are found from the capital of strange nature. Australia of the twenty or so species of kangaroo and Wallaby combined there are only three that can't pas a pregnancy Mitzi in fact it's the Timbre Wallaby that can put embryos on hold for up to eleven months. There were few mechanisms at work here. Some animals most made right after giving birth. It's like a backup plan in case something happens to the newborn if nothing bad happens in. The newborn is nursing the physical taxation of lactation lactation stalls the understudy fetus once the extant offspring is weaned. The fetus begins developing again. The second way is to pause every pregnancy until the time is right usually to do with the weather for example minks mate around the start of March but put the embryos on pause until after the spring spring equinoxes when the days are getting longer in the northern hemisphere this ensures that the young are born in spring when food will be more plentiful than the temperatures more mild. Some are bitterest animals will pause pregnancies in times of drought hoping that the rain will come back to get plant life growing again. The TAMRA wallaby combines these two methods to ensure that the Joey is ready to leave the pouch in spring rather than the middle of a Hot Australian Summer Dia Pause was first identified in eighteen fifty. I four after hunters in Europe. Notice that pregnancy in Rodier seem to last a lot longer than in other types of deer since then scientists have been fascinated by this process. And it's helped us understand more about basic reproductive processes in all mammals but how the process worked at the molecular level is still a mystery mystery until recently there seemed to be no connection between which speech these use it in which didn't and there didn't seem to be a unifying mechanism for how the pregnancy was caused. Even the hormones controlling dia paws are different between Mammal groups researchers in Poland were able to pause embryos in a sheep a non dipoto species by transferring them into a mouse uterus and then back into the sheep with no apparent ill effects this indicates. It's the potential for Dia. Pause could lie in mammals including humans but I would still take my birth control pill you would. Experiments would die. Applause could do you for us is to improve our understanding of how to make and select healthy embryos for in vitro fertilization as well as to create better stem cells that could be used the target cancers the first stem cells ever isolated by scientists came from a mouse embryo in diapers whether or not the pregnancy. Let's see was paused. Once the baby or babies come out they need to eat and for mammal babies. That means milk. A mother's milk contains a concoction of nutrients France fats proteins and carbohydrates that are essential for a baby's development as well as a cocktail of protective factors to effectively supply the baby with immune hyun system until it can develop its own all mammals produce milk but they don't all produce the same milk to give you a baseline for comparison before I start start throwing out numbers cow. Milk is about three and a half percent protein and five percent carbs while human milk is about one percent protein and seven percent and carbs and both are about eight percent water. You won't find much water. In the milk of the hooded seal. Their milk is more than sixty percent. Fat Thatch more like a premium milkshake than milk. This high fat milk is crucial for the seal pups born into the freezing waters of the North Atlantic and Arctic oceans. It's the PUPS also only nurse for about four days having been born on floating ice an environment that is both unstable and unreliable. So the seal Momma needs to pack a lot of energy dense fat into her milk. The pups consume over sixteen pounds or seven kilograms of milk every day. Their Body weight doubles in the first week of life. Conversely in the savannahs of Africa the Black Rhino has the skim milk going only about point the two percent fat they also nursed for almost two years which is only possible within milk given how many resources lactation demands

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