Interestingly, Swenson soon determined that these size and color variations actually corresponded to separate species, not size and color variations within a species. Further, all colonies appeared to be multi-species, and all apes appeared to live in colonies. Within each colony, one species, brown in color, dug and maintained elaborate tunnel systems, with galleried nesting dens. Another species engaged in rude cultivation, planting and propagating the “grasses” in exposed mud flats. A third species “stood guard” at the colony perimeter, making gestures quickly understood as threatening by early settlers—this species proved most troublesome to settlers, at is possessed sharp, chitonous, cutting spines which it used to fatal effect until colonists began shooting them on site. Another species, more massive than the others, burrowed water diversion channels that created new mud flats for planting. Swenson believed that the two species of Lesser Apes, named Swenson’s Marmosets and Swenson’s Shrews, were commensals—animals that lived only in association with the colonies, but had no specific role within it. Both scavenged food and material wastes and created smaller sub-colonies ringing the main dens. They may have been tolerated for their “alerting” function, as they became quite agitated on the approach of any person or animal. The largest species, usually white, but sometimes black, in color, served no visible function, although it prowled widely within the colony itself and throughout the surrounding “fields.”
Swenson found the apparent stability of this “social symbiot” colony structure to be remarkable, because the colonies were few and far between, none of them large, with most colonies including no more than a few individuals of any one species. How, he wondered, did their populations remain viable?
Zebras, Mules, and Truth Stranger than Fiction
Swenson noted that, on various occasions, each species had been observed carrying what were clearly offspring, but no offspring had ever been observed among the “zebras,” which were also least numerous. Swenson initially presumed that “zebras” were sterile hybrids, often called “mules,” the result of a chance mating between two Ape species. However, the fact of interspecies generation of offspring aside, it became clear to him that appellation “mule” was a misnomer— a fact with profound implications for understanding the reproductive agenda of all Swenson’s Apes in general.
Swenson found that “zebras” were not, strictly speaking, hybrids. Hybrids form from the fusion of gametes (egg and sperm) from two species to form a single zygote (fertilized egg) that will develop if and as possible. For example, an actual hybrid mule is the offspring of a male donkey, which has 31 pairs of chromosomes, and a female horse, which has 32 pairs. The resulting offspring has 63 chromosomes. This odd number of chromosomes results in an incomplete reproductive system, which is always sterile in males, and usually sterile in females.
Swenson’s Ape crosses are not “mules” in this sense. Rather, they are chimeras. Chimeras result from the physical mixing of cells from two independent zygotes (fertilized egg cells). “Chimera" is a broad term, applied to many different types of cell mixing. Although cross-species mixing is possible among species that are closely related and share similar developmental physiology, most chimeras result from the mixing of cells within a species. Chimeras can often breed, but the fertility and type of offspring depends on which cell line gave rise to the ovaries or testes. Intersexuality and true hermaphroditism may result if one set of cells is genetically female and another genetically male, and as we will see, this is nearly always the case in Swenson’s Apes.
Nevertheless, we can use the cross-species equid analogy to clarify how chimeras differ from hybrids. As stated, crossing a male donkey with a female horse produces a hybrid mule. That is, one sperm of a donkey fertilizes one egg of a horse, resulting in a mule that shares the DNA and characteristics of both parents. It gets long ears from Dad, a short, glossy coat from Mom, and a DNA test of either its ears or its coat would show DNA from both parents.
A chimerical animal would result if one fertilized egg of a donkey (with both male and female donkey parents) were mixed with another fertilized egg of a horse (which had both male and female horse parents). Such an animal would develop so that some of its organs were “pure” horse (with 32 pairs of chromosomes and 100% horse DNA), while others were “pure” donkey (with 31 pairs of chromosomes and 100% donkey DNA). In addition, depending upon how the growing cell lines migrated, the animal’s coat might have patches of shaggy, grey donkey hair alternating with patches of slick, brown horse hair. A DNA test on such an animal would only show the DNA for the specific cell type and location tested. The DNA for the shaggy, grey parts of the coat would be pure donkey; the DNA for the slick brown parts of the coat would be pure horse. To have the “full” genetic picture for this creature, you would have to draw DNA samples from multiple locations. Notably, in Swenson’s Ape crosses, classic chimerical Blaschko's lines (fur striping) occurs, with the colors showing the boundaries of the cell lines.
Finally, whether a chimerical donkey-horse was interfertile with either donkeys or horses would depend on which cell line comprised its reproductive system. Even if the rest of its outward appearance were that of a donkey, if it had 100% horse cells in its reproductive system, when bred to a horse, it would produce a 100% fertile horse, with a full 32 pairs of horse chromosomes, and no donkey characteristics whatsoever.
Understanding this distinction is crucial for understanding Swenson’s Ape reproductive physiology and secondary sexual characteristics, because Swenson subsequently found that all Swenson’s Ape species are profoundly chimerical. Chimerism not only occurs within and across all Swenson’s Ape species; it is both a usual and an essential part of their reproductive lifecycle.
Most Swenson’s Ape matings result in multiple zygotes (fertilized cells), that is, fraternal twinning. Thereafter, any or all of four types of chimerism may (and usually do) occur. These are: stem cell transfer, tetragametic, germ line, and parasitic chimerism. This means that Swenson’s Ape offspring may inherit multiple cell lines from each parent, and these cell lines may or may not be fused n vivo. In the upper classes, parasitic chimerism results in asymmetry, as discussed below.
Stem cell transfer occurs via cross-placental blood-vessel connections between twins, and is especially common for stem blood cells. In this case, the individual’s bloodstream, immune system, and bone marrow will have different DNA from other parts of its body.
Tetragametic chimerism occurs through the fertilization of exactly two ova (two gametes) by exactly two sperm (two more gametes), followed by the fusion of the zygotes (the two fertilized eggs) at a very early stage of development. This results in an individual with intermingled cell lines. That is, the chimera is formed from the merger of two fraternal twins. The resulting individual can be male, female, or both. In Swenson’s Apes, for reasons as yet not well understood, both is most common.
Similarly, germ line chimerism occurs when multiple ovi are each fertilized by one or more sperm. The fertilized eggs then divide, and the resulting blastocysts (cell clumps) may or may not fuse to form one or more chimeric embryos. These embryos exist for a fairly extended period prior to implantation, and then may attempt to implant at the same hemophore (blood vessel node.). In this case, the embryos merge. If this happens, one embryo atrophies, except for the reproductive cell lines, which complement those of the other embryo. The twin then develops normally, except that it bears the reproductive cell lines of its sibling. If the merged embryos were of opposite sex, this results in a truly hermaphroditic individual. Again, in Swenson’s Apes, for reasons as yet not well understood, this is the most common outcome.
Parasitic chimerism occurs slightly later in embryonic development, when a “male” embryo attaches to a “female,” eventually fusing into a single, hermaphroditic individual with a shared circulatory system. “Male” and “female” are indicated parenthetically, because at this stage of development, the embryo consists of little more than an undifferentiated alimentary canal, with no dev
eloped digestive capacity or limb differentiation, and either or both embryos may already be stem cell, tetragenetic, or germ line chimeras.
The War Between the Sexes
In a further elaboration of this trend, all asymmetric Swenson’s Apes (that is, classes excluding Swenson’s Marmosets and Swenson’s Shrews) are chimerically hermaphroditic, and are formed in vivo from the “parasitic” attachment of a “male” germ line embryo to a vestigial genital pore formed at the side of the head of a “female” germ line embryo. On contact, an enzyme digests the lips of the (attaching) mouth and the (attached to) pore. At this point, as blood vessels form, the circulatory systems of the pair fuse.
“Male” development then continues as follows: First, the attaching embryo forms and injects male gonadal stem cells, which migrate to colonize the (female) birth canal. Given appropriate hormonal triggers, these gonadal colonies form multiple testes, one or more of which may or may not produce viable sperm, and may or may not descend, depending upon various factors that affect hormonal regulators, including rank, age, courtship rituals, and nutritional status. Most commonly, multiple testes produce sperm, but none or one testis descends. Second, in response to hormonal and enzymatic triggers, the axial limb buds migrate dorsally, and continue growth as the “gripping” hand and arm—creating the “asymmetrical” physiognomy of the “upper” Swenson’s Apes.
Under specific circumstances, reproduction within a caste may proceed sexually, asexually, and/or chimerically. All Swenson’s Ape matings are spermatozoically competitive. During mating, the hermaphroditic pairs exchange sperm packets. Because of the chimerically redundant testes, these sperm packets may (and usually do) contain sperm from multiple germ lines. Sperm may be stored in special ducts for long periods, perhaps even years. This means that once a Swenson’s Ape has mated, under some conditions it is capable of continuing to bear offspring until its stored sperm is exhausted or dies. Because of the prevalence of hermaphroditic chimerism, all fertile Swenson’s Apes are also capable of self-fertilizing without ever mating at all, although this seems to be rare and has not been observed in the upper castes.
An additional factor accounts for previous reports of so-called “sex changing” in Swenson’s Apes. In the case of sexual reproduction, two Swenson’s Apes initially engage in elaborate courtship ritual and display, which stimulate associated hormonal production. At the end of this first phase, a bank of highly muscular sacs are excited and contract. These eject up to 144 chitonous “love darts,” similar to those produced by common land snails. Thereafter, sperm packets are exchanged.
Received packets are “split” by an enzymatic process that both triggers ovulation and dilates storage ducts, releasing stored sperm. All sperm—the recipient’s own, plus all lines within the received sperm packet— then “compete” to either re-enter storage, or ascend the birth canal and fertilize all available eggs. Sperm that do not reach the “safe haven” of a storage duct or an egg are scavenged by digestive enzymes. Conception normally results in multiple zygotes, for both parties.
However, the mucous coating on the “love darts” contains a powerful hormonal cocktail that blocks further production of androgenic (male) hormones and excites production of oogenic (female) hormones. This leads to retraction of the testis and growth of a placental bed, enabling embryonic implantation. At this point, given sufficient hormonal injection, a “darted” Swenson’s Ape becomes “female” for the purposes of gestation and birth. It is therefore theoretically possible for both Swenson’s Apes to become pregnant as a result of mating, but this has not been observed. The prevailing theory is that Swenson’s Apes sequester a significant proportion of available oogenic (female) hormone precursors in love dart mucous, thus rendering their bodies so depleted that they are unlikely to “receive as much as they give.” Thus, it may be a matter of chance that one or the other Swenson’s Ape will have further developed “love darts,” and thus have give up the chance at “being female.”
Where Have All the Flowers Gone?
At this point, we might well note: these creatures have a bizarre reproductive physiology. We might indeed ask: why!?
In the absence of any physical specimens, I can only speculate, but speculate I will. To begin, we must turn back to that basic foodstuff of the Swenson’s Apes: the “grasses” distributed thickly on the mudflats of the lower Oquirr delta. As is well noted, vegetation on New Utah is now sparse, but on first arrival our Founders reported vast, lush, green fields, glinting “almost aquamarine” in the long, sunny days. The “pastures” nourished man and beast alike: among its other ingredients, an old Founder’s soup recipe calls for “one measure marsh grass, dried and powdered.”
In fact, those pastures were not grass at all; they were the tall stalks of a semi-terrestrial plant, more closely akin to so-called blue-green algae (cyanobacteria), that survives its march up out of sea water by forming dense, root-like, rhizomous subsoil mats that wicked water and dissolved nutrients upwards from the (saline) water table. In a unique adaptation, excess salt is excreted in small beads that form at the tip of each stalk. Almost no stands now exist, because under True Church direction, all of the Saint George plain and most of the Oquirr delta were quickly put to the plow, followed by pivot irrigation and drainage systems to combat soil salinization. Once the rhizome mats are destroyed by plowing, stands do not regenerate.
It was the plowing of these algae fields that led to the first contact (and conflict) with Swenson’s Ape colonies. Early on, construction and agricultural activities in close proximity to colonies themselves did not seem to result in anything but excitation among the Lesser apes. However, the first team to run gang plows through adjacent “grass” stands met with a quick and bloody end. Swenson was fairly certain that this algal grass was a primary colony food source, and that the attacks on humans had been made in defense of “colony-owned” fields. Thereafter, colony clearances were conducted as part of plowing operations. Colonists were quick to identify and pick off the “watchdog” species; thereafter, the other Greater Apes generally fled. The commensals were more problematic: colony clearance was generally followed by a local population explosion. Considerable effort went into their subsequent extermination, generally by gassing and poisoning.
This provided Swenson with hundreds of specimens of Lesser Apes for dissection and analysis, and he came to a startling conclusion. In brief: primitive blue-green algaes require and utilize selenium and iodine as powerful, highly-soluble antioxidants, readily available in sea water, to excrete excess oxygen during photosynthesis. However, this becomes problematic on land: because it is highly soluble, selenium quickly leaches from soils, especially under conditions of high rainfall—or artificial irrigation.
In general, terrestrial plants cope with the absence of these antioxidants by manufacturing their own, such as ascorbic acid, polyphenols, flavonoids, and tocopherols. However, some terrestrial plants, like aquatic seaweeds, actually accumulate and store selenium and iodine, and the New Utah algal grasses are among these. In these “grasses,” selenium uptake is regulated in the rhizome mats. Hence, when the mats are destroyed, so is the uptake mechanism—and thereafter selenium is quickly leached from the soils.
Also in general, terrestrial animals can and do utilize many antioxident forms, as well as sequestering trace amounts of selenium and iodine in the thyroid gland, or its equivalent. However, in the case of Swenson’s Apes, or, at least, in the case of the Lesser Swenson’s Apes, selenium deficiency resulting from collapse of access to the algae fields was especially dramatic in its effects on reproductive hormonal regulation. Absent selenium, “love dart” manufacture all but stopped. Initially, this resulted in increased oogenic (“female”) hormonal levels and “feminization” of the population (since no female hormones were being withdrawn from the body for dart manufacture). At the same time, reproductive drive increased, as did copulation rates. Given the total number of live births, Swenson postulated that hermaphrogenic reproduction also to
ok place, but he was unable to prove this. In any case, the immediate effect was a local population explosion. However, the second consequence of selenium deficiency became manifest in isolated individuals: spontaneous, habitual abortion and miscarriage. Outwardly, apparently “female” Swenson’s Apes gradually sickened and died, as internal egg and sperm stocks were repeatedly fertilized, aborted, and reabsorbed.
Conclusion
So again, why this bizarre reproductive physiology? Our research resources here on New Utah are, to say the least, limited, and I am more historian than xenobiologist, but I will draw some tentative conclusions from what I know of old Earth specimens.
Chimerism and hermaphroditism are most common in (especially) aquatic species characterized by low population densities and high potential birth rates. These include angler fishes, marine and terrestrial mollusks, and other animals that live in isolated populations that rarely encounter one another, including some of the lower primates. In these animals, chimerism and hermaphroditism ensure that multiple germ lines are carried within each individual, maximizing the potential for genetic diversity with each “chance” encounter—or, in the absence of an encounter, via hermaphroditic reproduction within the “individual” itself. A Swenson’s Ape colony is, in effect, a “gene bank,” representing germ line biodiversity far beyond that of the number of its members.
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