October 18th, 2007

Ann Vole

reproduction methods and why we are special

First I will separate reproduction into cloning and genetic based reproduction. Plants are good at cloning. Most plants, when provided the right conditions will grow roots or leaves from the opposite parts of the original plant. Seedless bananas you normally by in the store have to be reproduced that way (due to a lack of seeds) and thus are clones (but there are lots of seeded varieties but who wants to pick out the seeds). Hydra are a type of small aquatic creature often studied in biology classes because they are animals who usually reproduce by "budding" where a new clone of the parent will grow out the side and when it is mature enough will break off and live on it's own. Most microscopic creatures divide into two as the prime means of increasing their numbers.

For genetic based reproduction, there are four basic ways of giving offspring a unique genetic code. Gene recombination is common in microbes where the two microbes get all their chromosomes loose and unattached and attach to each other to mix the chromosomes together then each take they right number and type of chromosomes (but not likely the same ones they came with) and go on their way as a new creature genetically. Hybridization is where all the genes from both parents are present in the offspring. A few creatures will hybridize then the offspring will eliminate the unused chromosomes and are then ready to hybridize again (otherwise hybrids are usually sterile like mules who are hybrids of horses and donkeys who each have different numbers of chromosomes so they will not pair up so can only combine as a hybrid (mules have the complete chromosomes of both parents). Gender is not really important to many small creatures and lots of plants so many reproduce asexually. Asexual reproduction is where both parts of the genetic combination are provided by the same individual. Earthworms are asexual so two meet and they both give sperm to the other and both use that sperm to fertilize their eggs. many plant flowers both give off pollen and receive pollen from other plants to fertilize the seeds for the fruit fruit. And the forth way is is the usual male-female paring where the male gives sperm or pollen to the female to produce babies or fruit/seeds

The offspring need to go from a single cell to an adult and any help the parents can give it will increase the chance that each parent will propagate their genes so any genetic changes that would help the parent help it's offspring are going to increase such genetic changes in the population. Plants will include lots of high nutrient food in the seed or the fruit or make the fruit tasty so animals will move the seed to a new location and fertilize it (poo). Animals will usually provide lots of energy in a yolk sac or more simple eggs will just have the young develop in a nutrient slurry in the egg. Reptiles and birds use the yolk sac method so the baby has a chord attached to a yolk sac and results in the equivalent of a belly button where the yolk used to be (completely absorbed by the time the baby hatches). Marsupials (like kangaroos) and monotremes (egg laying mammals like platypus and echidna) also have a yolk sac but the yolk is rather small and the baby has to receive nourishment by milk. Marsupial fetuses (unborn babies) are like babies in eggs but instead of having an egg shell, they live in the uterus of the mother until their yolk is used up and they come out and crawl to the mother's teats to finish development. Monotremes are similar but have a leathery egg shell and the baby (called a puggle) hatches and then drinks milk from a patch of skin with 100-200 pores that ooze out milk when the baby licks the area. Why not develop in eggs? Mammals are warm blooded and use up a lot of energy so the egg size for a mammal would have to be rather large and after hatching, the baby will still need food brought to it by the parents for a while before teeth can develop. Birds have the advantage of functioning beaks when they hatch and parents that can fly to bring food (most bird species anyways) and monotremes do not have teeth. An example of the large egg size needed for mammals is the large size of the eggs of flightless birds: Kiwi eggs are more the 1/3 the weight of the mother... only one egg at a time and two years between making a new egg!

Placental mammals (including humans and voles) do things a little differently. Instead of a yolk sac, we have a placenta which is a barrier where the blood of the mother and the blood of the baby can be separated by a thin membrane where food and water can pass through without the immune systems attacking the other genetically different cells (mother's immune system attacking the baby or the baby's immune system attacking the mother's blood cells). With this arrangement, the high energy babies can develop more throughly before going to milk. Some mammals like hares are born with teeth and operational ears and eyes so are ready to live on their own from birth (but the first bit of milk from the mother provides the antibodies needed to have the baby be immune to all the diseases the mother has been exposed to)

Among mammals, humans are among the longest to nurse and the longest for babies to be helpless. I am guessing this is an adaptation to bore the kid out of it's mind and start to babble and make noises. These noises have months and years for the kid to figure out that they have meaning before the kid is distracted by living on it's own and finding a mate that most other 3 year old animals are already concerned with.

You may be wondering why I posted this... the reason is to provide a background for readers for me to speculate on possible alternative reproduction methods of intelligent mammal-like creatures from other planets (for various stories I want to develop)
Ann Vole

Reproduction on alien planets - part one

I will start with the main character of my epic webcomic idea due to having already thought through his biology a lot.

I wanted him to be easily mistaken for a mammal on Earth but I have his planet full of extremes in order to provide a low-tech way for him to travel to earth. One such extreme is a lack of oxygen in the atmosphere due mostly to the fact that the planet will get colder then the freezing point of oxygen at times. Due to this, the baby will have to develop with access to the body fluids of the parent to obtain the reactive element to convert stored energy to ions. We use oxygen to do this reaction in a carbon based lifeform system but some or all of the reactions could be changed to using nitrogen instead in a silicone based system. I like silicone because there are lots of silicone-based polymers that remain flexible at low temperatures... a requirement of this lifeform. I also need to be able to freeze the main character for centuries of space travel while being bombarded with radiation so I figured his body would be a lifeless machine full of microbes like blood cells that build and repair the body. This would allow the parent's life cells to build and repair the baby's body while connected but eventually the baby will have to enforce a separation of cells based on genetics or else be able to change the genetics of the life cells of the parent. I want my alien to be rated "G" while walking upright and not wearing clothing so I chose to put his genitals inside a pouch. I want to have a storyline on his planet about various things about racial and gender discrimination so I have two related species of aliens of which he is one of those two species. to give him gender confusion, I made his species to be asexual to a degree... the "males" out number the females several thousand to one but the "males" can share genetic material and both mother a baby. The other species is the normal male-female paring makes a baby in the female only but they are homophobic among themselves and have a low opinion of the other species. Lots of stories have a character living poor but really being royalty so I figured I would add that element. The main character's two "male" parents shared their genetics and both produced a baby but one of the babies was "female" so the whole family was instantly royalty as she would become queen when the current queen died or abdicated her throne. At the time there was lots of attempted murders of possible royal genetics by the other species to retaliate the royal line making the other species the equivalent of slaves. They took a gland from the other species and planted it in the main character's body so he would grow up to look like a female of the other species. The other species are a female dominant species due to the females being bigger to mother babies for so long but the main character's species is all "male" so not really female dominant even though their leader is "female". Due to this, I wanted their genitals to be almost identical between both species and genders. I figured nipple-like bumps that ooze genetic material when stimulated should work. My main character needs to keep his genitals hidden or his identity (as the other species and other gender) will become known (and in a homophobic society out to kill his kind). I am always fascinated by creatures with more them 2 genders like bees (workers, queens and drones) so I made that a part of this story. This planet is a liquid planet with floating islands of living matter. The main character's species has a "drone" gender that is to share genetic material with the queen and is also unable to have babies because he is a true male and is also as rare as queens are. Drones travel between islands to provide genetic diversity. At the height of this cold war between the species, the island breaks in two (or more) parts in a storm leaving the main character's family on the part of the island that has lots of the other species who figure it is a good time to overthrow power and do genocide on any remaining members of the main character's species. A drone who has arrived to the royal court on a different piece of the island since it's break up decides to save this newborn queen and uses self mutilation to disguise his gender and species and uses the excuse that a feared aquatic species tried to eat him. (edit... I was going to tell some story spoilers but they are not needed for the discussion of my characters gender biology) to make a long story short, the drone's genetic material was harvested and the main character takes it with him to earth so he can have royal children who can possibly make it back to his planet to repopulate it should nobody survive the coldest part of the planet's elliptical cycle. (there are other reasons in the character's minds but that is my biological reason for having his children return) This requires that the genetic part of the creature to be very durable and handle absolute zero and high radiation for centuries of space travel. To accomplish this, our two strands of genetic material that is repaired to match the other side when damaged is not going to do the trick so instead the genetic code is copied many times and the parts are averaged to reconstruct the original genetic code. To do this I was thinking of the genetic material to be like a virus and a cell just absorbs lots of these "viruses" and the mechanics of the cell will average the code of them. Being that the two genetic codes are mixed together when they "have sex", the resulting average will be different then the mother's code (including "male" mothers) so a new individual will form based on the influence of this new cell and the divided copies of it (mitosis). I also have to have this character mistaken for an earth animal so he will look like a female marsupial by having nipples in a pouch.