#genotypic variation

[shiut]

btw protip: when making fankid designs, look at the concept art of the parents for inspiration

[kedreeva]

This was posted to a peafowl group a friend of mine is in; it's a comparison between a European violet (front) and a European violet x US purple cross (back).

EVERY other color mutation, when bred to a non-same mutation, produces wild type coloration cocks. The sex-linked genes produce mutant hens, but not cocks. The birds have to be the same mutation in order to show any non-wild coloration.

The cross bird doesn't look like a purple; it's too red. It doesn't look like a violet; it's too blue. Which tells us that EV is either an allele to purple that co-expresses, or it's the same gene with different epigenetic markers that give it a different phenotype to US purple. We already know that purple mutated twice here (once in wild type stock, once in cameo stock), and they have a HUGE range of variation in how that expresses in the phenotype. We also know that when purple expresses with the bronze mutation, it results in two VERY different phenotype mutations- hazel and indigo. When hazel is bred to hazel, it produces hazel and indigo, and vice versa, with no discernible pattern to it.

I don't know which it will turn out to be. My guess is an allele. I hope that I live long enough to see the genotype mapped and the mutated genes IDed and published, so I can find out.

[mindblowingscience]

Climate change has a negative impact on food security. An international research team led by Wolfram Weckwerth from the University of Vienna has now conducted a study to investigate the natural variation of different chickpea genotypes and their resistance to drought stress. The scientists were able to show that chickpeas are a drought-resistant legume plant with a high protein content that can complement grain cultivation systems even in urban areas. The study is published in the Plant Biotechnology Journal.

Continue Reading.

[revretch]

I see people getting confused about what "male" and "female" means for non-human animals (and plants), because it is not at all the same thing as the way it's used for humans, because there are too many variations across many different animals. (I won't even touch on how weird it is for plants.) So to break this down:

Sex: The gametes an animal produces (female for the big gametes, or ova; male for the small gametes, or sperm; monoecious/hermaphrodite for both; asexual for neither). When referring to non-human animals, literally the only thing this means.

Gonads: The organs that make the gametes (ovaries for ova, testes for sperm). Sponges can make gametes without gonads, so gonads are not required for having a sex.

Genitals: A dizzying array of parts that can be used to transfer gametes between individuals. Some males have claspers for opening. Spiders have "penises" in their "hands." Female bark lice have siphons for sucking the sperm out of males. And the vast, vast majority of animals have no genitals at all, because they live in the ocean and just spray their gametes into the open water. Because this varies so much and can even be lacking entirely, it is also not the same thing as sex.

Genotype: What's genetically encoded in an animal. In some, like humans, there's an XX/XY chromosomal system to determine whether an organism makes sperm or ova. In birds, it's ZZ/ZW (that is, two of the same chromosome for males). In wasps, ants and bees, it's haplodiploid, where males have only one set of all chromosomes (the females, like almost all other animals, have two). In some animals, it's not related to genes at all--in crocodilians, sex is determined by the temperature the eggs are incubated at! So, genotype is not the same thing as sex.

Phenotype: The physical expression of an organism--the body. Up to you whether you're including gonads and genitals with that. This can vary depending on sex, to make it more likely animals producing different gametes will be able to identify each other. In some animals, there is absolutely no difference in phenotype between sexes at all. So, this is also not the same thing as sex.

Sex-Linked Behavior: Again, not even present in a lot of animals--or if it is, usually limited only to courtship and mating, because most animals aren't social. Also not the same thing as sex.

Gender: A complicated system that varies dramatically across cultures and is specific to human beings, and tied very closely to human language. Some cultures have only two genders. Some have three, four, or more. What an individual thinks of gender can vary irrespective of culture. It ties in with all the previous things in so many overlapping, intricately linked ways I could not go into them here. This can also be considered "sex," but not at all in the sense that we use it to refer to animals. Likewise, animals cannot be considered to have gender, because they lack the specific human language and culture that gender arises from.

Tl;dr: Please stop using "sex" the same way for both humans and animals. The human definition makes no sense for non-human animals because they get so weird, and it's just plain rude to refer to humans in the animal sense.

[amber-tortoiseshell]

i know youre primarily a cat genetics blog, but what do you MEAN theres multiple merle alleles?? i thought it was just one mutation

Merle genetics is the coolest thing: there are basically unlimited amount of alleles. (Well. Or at least there are about a hundred.) You see, this isn't a simple point mutation like most variants we deal with on this blog - what we have here is called a SINE or "Short Interspersed Nuclear Element". This is a piece of DNA that inserts itself into the gene.

Without going into specifics, this SINE region doesn't have a predetermined length, and the longer the insertion is, the more pronounced the merle phenotype becomes.

Under 200 bp we have the non-merle, wild type m allele with no insertion. Over that, well, different people have classified it differently, but basically there's a continuous scale of merle M* alleles. Nowadays the most reliable merle tests don't just give you an allele name like M or Mc, but an allele length like 264 or 222, too.

Winnie's merle allele has the length of 273. Very merle!

The alleles are additive: a shorter one in itself can't cause a standard merle pattern (although sometimes they have a kind of dilution effect), together with another they might be able. The "dangers" of merle and especially double merle also rises with the insertion length: combining two short alleles is safe, while longer alleles together are to be avoided by all responsible breeders.

The unstableness of the insertion means that mosaicism in this gene (when the dog has slightly different merle alleles in different body parts) isn't rare either.

Bibliography:

Advanced Merle Genetics

Educational Charts and Diagrams

Defining the Scale of Merle

The History of Merle

Length variations within the Merle retrotransposon of canine PMEL: correlating genotype with phenotype

Being Merle: The Molecular Genetic Background of the Canine Merle Mutation

Merle phenotypes in dogs – SILV SINE insertions from Mc to Mh

[metamatar]

If the experiment were constructed in a different way, different facts and truths emerge. Experiments need to be understood as “constructed” and we need to recognize that both scientist and the object of science (morning glories in this chapter) are important players in this theater. What understanding emerges about morning glories does so through the particular intra-actions of scientists and experimental subjects (Barad 2007)—they together produce the “truth” about morning glories. To the extent that science fails to attend to this, science uncovers only a fraction or at times only a fiction of the story.

The results of my morning glory experiments were significant, showing that patterns of flower color were not random but rather the acts of balancing selection. But the results were produced through a carefully constructed and contrived experiment. The experiments were designed to be “good” experiments where the results were definitive with clear and easy interpretation, and where ambiguity was minimized. In this sense, the experiments were well designed. But what exactly do these experiments reveal? In order to be positive that the effects are solely due to the variables in question, experiments need to be carefully constructed. This involves artificially producing the experimental plants with known genotypes as well as carrying out the experiments in controlled and sometimes artificial contexts. In these particular experiments, in order to produce the experimental plants that were genetically identical (exceptfor precise variation in the w locus), several steps had to be undertaken. For instance, genetic crosses were carried out in plants grown in the greenhouse away from the uncontrollable lives of pollinators; seedlings were first grown in the greenhouse and then transplanted in the field; individuals that failed to germinate were replaced with similar genotypes to ensure a good sample size; plants were grown in controlled fields so the frequencies of the flower colors could be controlled; plants were planted in rows individually at regular intervals and equidistant from each other; plants were twined on their own bamboo stakes and not allowed to spread randomly on the ground or on each other (as they often do in the wild) in order to identify the flowers and seeds of individual plants; pests such as cutworms, deer, or other animals were kept out of the experimental plots. All the above were necessary to produce results with enough of a sample size to discern a pattern, and thanks to all of these I was able to finish a dissertation! And to be precise, I showed that under all the above conditions, balancing selection is important in its action. Yet because it is a reductionist science, I am left to wonder about the vagaries of everyday life, the random stochastic events that disrupt natural populations, the degree to which the design drove the conclusions. And there is always the matter of scale at which results emerge. Limitation of modern scientific life—graduate school, money, tenure clocks, resources, and weather patterns—all shape the knowledge the scientist, the context, and the culture of science and the plant co-produce.

In addition, my experiments with morning glories assumed a “genes versus environment” paradigm. Genetic lines of morning glory were formed to create uniform genetic contexts in which the only variant was the flower color at the w locus. The flowers were then grown in fields where little else grew. The experiments could not explore whether or not genes interact with other genes, or if the expression of genes at times depends on their environmental contexts in complex and even unpredictable ways. My carefully constructed experiments were not designed to capture the complexities of environmental contexts outside the experimental cycle. Latour’s invocation of scientific experiments as theater is an apt analogy. The theater is itself built as an “objective” event with the scientist’s own history and social identity deemed irrelevant, the experimental organism is stripped of all context and agency, and the objects of study are manufactured to minimize variation. The play itself is conducted on a stage that is carefully manipulated to produce as generic and sterile a location as possible so it can then be reproduced easily in other generic and sterile locations. With the observer, organism, and location set aside, the play unfolds to reveal some “truth” about biology and nature.

It is not that I contest the impulse for clarity that drives the research design and methods that I used in my training; it is more that this theater stands for pure knowledge about nature. Furthermore, so much is left out of the story of morning glories. I worry about the myopia produced by the rigid and futile effort to set boundaries on nature and culture that precludes and excludes so much complexity. How would the morning glory change if the boundaries were abandoned?

In many ways, I am arguing that most biological experiments (including my own) are, if we are precise, naturecultural experiments themselves. They are only deemed natural or rendered purely biological by ignoring the cultural contexts of theories, plants, and humans. Innumerable social and cultural assumptions are deeply embedded within the experiments and therefore in knowledge we produce about the natural world. Identifying these assumptions and reconceptualizing scientific practice as directed at the entanglement of nature and culture requires interdisciplinary effort. My primary argument is that if the biological sciences care about producing knowledge about nature and the humanities and social sciences care about producing knowledge about culture, both should be invested in the stories told about morning glories and other organisms.

Ghost Stories For Darwin, Banu Subramanium

[hanszoe]

i guess i had a longer post before but since i'm working on it now, a quick summary of hans' muscle composition

first is that they have a lot of explosive strength. their height and weight was confirmed as 170cm/5'7" 60kg/132lbs even before the anime adaptation, so it's true to how isayama imagined them. in the above scene that compares to pastor nick's height and weight of 192cm/6'3.5" 72kg/159lbs.

in the anime adaptation this action lasts a total of 1m14s.

35s - bearing initial weight. nick is still supporting himself and hans is not holding him that far from their combined center of mass. 22s - hans pushes him further over the ledge, increasing the distance of their center of mass from their body. this increases the amount of force that they must exert in order to hold him up. at this point hans' arm begins to shake, caused by their muscles beginning to alternate between fibers to distribute demand 17s - nick stops supporting his own weight, further increasing the amount of force hans has to exert to hold him up. killing him should not only be a mental question but also a physical one at this point

they then use the last of their strength to throw him back over the ledge. their entire body is shaking when they sit down.

the situation is somewhat unrealistic, especially hans' pose as regardless of their muscle strength they are at a major mass disadvantage and would absolutely have to place more of their own weight away from the ledge (this would naturally occur by widening their stance and lifting their unused arm on the opposite side) to avoid falling, but overall within the realm of possibility. regardless, it takes a lot of explosive strength to do something like this.

hans also has similar explosive strength on a few other occasions, notably when they kick over this table.

however in contrast, they don't seem to have much endurance

they're so exhausted from running presumably just a short distance from their horse to tell erwin that they drop to the floor lol. as if it were a regular occurrence, erwin just gets them a glass of water

so hans' endurance definitely doesn't compare to their explosive strength. which actually makes sense, considering two totally different types of muscle fibers control these types of movements.

the first type, which hans definitely has a large distribution of, are fast twitch muscle fibers. those ones use an anaerobic process to generate energy, which is also why they aren't breathing heavily after holding nick over the ledge, as their muscles used almost entirely anaerobic glycolysis to generate the energy required for the action.

the second are slow twitch fibers, used over longer durations. they use aerobic metabolism to generate energy, so this is why hans is breathing so heavily after running.

based on the disparity in their respective areas of strength, hans most likely has a higher distribution of fast twitch fibers. there is a certain gene which controls this, the ACTN3 gene. that one encodes alpha-actinin-3, which is a protein only expressed in fast twitch muscle fibers. allele variations control whether alpha-actinin-3 is actually encoded at all. individuals with a CC genotype have full expression of the gene, whereas CT or TT result in reduced production up to no production at all in individuals with a TT genotype. this is called ACTN3 deficiency. without alpha-actinin-3, muscles are shifted towards aerobic metabolism and fast twitch fibers work less efficiently.

it's actually very cool that hans' physical strength is so consistent in this way that we can even speculate on their muscle composition, up to them likely having a CC ACTN3 genotype. i haven't read much of isayama's blog but he used to post a lot about sports up to betting and predictions, so it seems like his particular athletic knowledge came into use here to depict them.

[adobe-outdesign]

Theory: gravity-defying hair in the Pokémon universe is a trait affected by gender dimorphism. There’s more variation within each gender than between them, like with height and body hair in real life (5’5 men and 5’8 women aren’t uncommon), but it’s stronger in males of similar genotype.

Evidence: Volo’s hair flows up, Cynthia’s does not- even parts of it that are cut short, like her bangs. Cyrus’ hair stands straight up, Cyllene’s is just a little bouncy. Adaman’s hair is very bouncy, Perrin’s is flat.

^ trans

[neopronouns]

flag id: the top left flag has 3 stripes, which are dark purple, cream, and golden yellow. the top right flag is made up of 3 wide x shapes, each one smaller than the last and centered within the flag. from largest/outer to smallest/inner, they are light yellow, golden yellow, and dark purple.

the bottom left flag has 3 vertical stripes, which are golden yellow, dark purple, and golden yellow. the bottom right flag has 6 stripes, with the third being largest, the fifth about half that size, the second and fourth slightly smaller, the sixth slightly smaller, and the second much smaller. they are golden yellow, dark purple, golden yellow, medium purple, lighter purple, and golden yellow. end id.

the bottom left flag's stripes are very dark indigo, medium dark blue, dull green, pale cyan, dull light red-pink, and faded pink-red. the bottom right flag's stripes are very dark indigo, medium dark blue, dull green, pale pinkish-purple, light faded pink, and dark faded red-pink. end id.

banner id: a 1500x150 teal banner with the words ‘please read my dni before interacting’ in large white text in the center. end id.

interphenotype | intergenotype intergenital | intergonadal

interphenotype: experiencing phenotypic intersex variation

intergenotype/interkaryotype/intergenetic: experiencing genotypic (karyotypic/genetic) intersex variation

intergenital: having intersex genitalia

intergonadal: having intersex gonads

[pt: interphenotype: experiencing phenotypic intersex variation

intergenotype/interkaryotype/intergenetic: experiencing genotypic (karyotypic/genetic) intersex variation

intergenital: having intersex genitalia

intergonadal: having intersex gonads. end pt]

flags for some intersex terms for anon! they're all based on the intersex flag.

the interphenotype flag is similar in format to my presentation flags (since phenotype is essentially what your genotype 'presents' as), the intergenotype flag is made of x's since they're sort of similar to simple dna models, intergenital is based on other genital flags (like xenogenital), and intergonadal is based on other gonadal flags (like angonadal).

tags: @radiomogai | dni link

[eternal-echoes]

“Human behaviors that many consider to be socially constructed gender stereotypes also appear in primates. Take, for example, young vervet and rhesus monkeys: females prefer to play with dolls, whereas the males opt for toy cars and a ball.(26) Or consider the wild chimpanzee: The females are more likely to cradle a stick in their arms as if it were a baby, whereas the males use the same sticks as weapons.(27) Like humans, if young males apes aren't given the opportunity to play fight with one another, they become more violent as adults.(28)

Many of these gender-related behavioral differences are impacted by hormones. Whereas baby girls tend to prefer the sight of human faces and make more eye contact than male babies (who prefer to look at mechanical moving objects), girls who were exposed to higher levels of testosterone in the womb make less eye contact. Females who were exposed to higher levels of testosterone tend to be less interested in children and have a more difficult time interpreting others' emotions, whereas women with lower levels of the hormone are more interested in parenting, wearing makeup, dressing up, cooking, and interior decorating.(30) Those with higher levels of testosterone tend to be more aggressive, to have decreased verbal abilities, and to have better spatial orientation abilities.(31) However, as the DSM-5 points out, "the prenatal androgen milieu is more closely related to gendered behavior than to gender identity.”(32)

Although behavioral differences offer evidence that sexual distinctions aren't merely culturally constructed, it should be reiterated that women who engage in gender nonconforming behavior are no less female than the women who exhibit more typically "feminine" behavior patterns.”

-Jason Evert, Male, Female, or Other: A Catholic Guide to Understanding Gender

—

Work cited:

26) Cf. Dick Swaab, We Are Our Brains (New York: Penguin Books, 2014), 58; M. Hines, "Sex-Related Variation in Human Behavior and the Brain," Trends in Cognitive Sciences 14 (2010), 448-456; J. Hassett et al., "Sex Differences in Rhesus Monkey Toy Preferences Parallel Those of Children," Hormones and Behavior 54 (2008), 359-364.

27) Cf. S. Kahlenberg and R. Wrangham, "Sex Differences in Chimpanzees' Use of Sticks as Play Objects Resemble Those of Children," Current Biology 20 (2010), R1067-R1068; E. Lonsdorf et al., "Boys Will Be Boys: Sex Differences in Wild Infant Chimpanzee Social Interactions," Animal Behavior 88 (2014), 79-83.

28) Cf. J. Higley, "Aggression," in), Primate Psychology, Dario Maestripieri, ed. (Cambridge, MA.: Harvard University Press, 2003), 17-40.

29) Cf. A. Nordenström et al., "Sex-Typed Toy Play Behavior Correlates with the Degree of Prenatal Androgen Exposure Assessed by CYP21 Genotype in Girls with Congenital Adrenal Hyperplasia," Journal of Clinical Endocrinology & Metabolism 87 (2002), 5119-5124; Cf. Swaab, We Are Our Brains, 59.

30) Cf., Blum, Sex on the Brain, 184; J. Udry et al., "Androgen Effects on Women's Gendered Behaviour," Journal of Biosocial Science 27:3 (July 1995), 359-368; E. Chapman et al.,"Fetal Testosterone and Empathy: Evidence from the Empathy Quotient (EQ) and the 'Reading the Mind of the Eyes' Test," Social Neuroscience 1(2006), 135-148; F. Purifoy and L. Koopmans, "Androstenedione, Testosterone, and Free Testosterone Concentration in Women of Various Occupations," Social Biology 26 (1979), 179-188.

31) Cf. Glezerman, Gender Medicine, 75; P. Celec et al., "On the Effects of Testosterone on Brain Behavioral Functions," Frontiers in Neuroscience 9 (February 17, 2015), 5.

32) DSM-5, 457; Cf. L. Gooren, "The Biology of Human Psychosexual Differentiation," Hormones and Behavior 50(2006), 589; Thomas E. Bevan, The Psychobiology of Transsexualism and Transgenderism: A New View Based on Scientific Evidence (Santa Barbara, CA: Praeger, 2014), 111-115.

—

For more recommended resources on gender dysphoria, click here.

[sufficiently-analyzed-magic]

The Sliding Scale of Eeby Deeby (trademark pending) (not really)

So there's a lot of humans-turned-Pokemon on this website, and I've gathered that you refer to yourself as "eeby deebies" (whatever that means). So as a scientist of the supernatural, I had no choice but to create a taxonomy of eeby deebies.

Note: To fit onto this sliding scale, you have to have once been on either extreme. If you were born as a hybrid/abomination (affectionate), you're a different and yet still incredibly interesting thing yourself. Though the primary definition is those who were once human, those who were once regular Pokemon also technically count by my measure.

On one end of the scale, we have: Normal Human Being. You have not been eeby deebied. You are genetically and phenotypically human.

Now, the next level up is Silent Eeby Deeby. You look human, and you act relatively human, but technically you are part Pokemon. Genotype vs phenotype. Maybe you knock things off a desk on instinct now and again, but you're still human-ish.

And then we start getting into the fun stuff. We're at the skittygirl level. And just general Pokemon traits regardless of gender or species. Whether or not behaviour is affected, you sit at the level of Skittygirl. The level is named Skittygirl because that really embodies what I mean by Pokemon traits. You don't have to be a Skitty hybrid or a girl to count.

Now we have two of my favourite levels. The first here being Hybrid/Abomination (Affectionate). You're an affront to Arceus' design, and we love you for it. No other explanation needed.

And then there is what I call Werelycanroc, or, if you wanna be more technical about it, Shifters. These guys can, well, Shift. Voluntarily or otherwise. They might look normal one day (or they might never look normal), and be a total Lycanroc the next (or they might never fully shift). This level has a lot of variation.

Here we have the levels where you start to look more Pokemon that human.

The Reverse Skittygirl is the reverse of the Skittygirl classification. That sounds obvious now that I type it, but it's essentially a Pokemon with human traits. Occasionally horrifying!

Next is our lovely friend the Talking Pokemon. What it says on the tin. The talking is usually powered by magic but occasionally they just Have Vocal Cords.

The next level is the Intelligent But Can't Talk Pokemon. Also what it says on the tin.

And the final level is Just A Pokemon. No more intelligent than a regular member of their species, usually can't type. Most likely level to be under the care of a Trainer.

Thank you for reading the Sliding Scale of Eeeby Deeby. Note that as it's a Sliding Scale, there's levels within levels and places on the spectrum, so there's nuance to it.

[amphiriteaquarium]

you win....lORE AND MERMAIDS WOAH AOAH.(i'm lazy)

These is 2 of the 6 so....yeah!

Gather around my sweet guppies as i tell you about something you may or not way to hear about. So in the world of sbr there is "tribes" which refers to different mer.

Atlantic:

Due to the amount of history ,specially around travels and economy this ocean has it makes sense this poblation has interacted more than humans than any other.

Pacific:

i KNOW you have seen those north sea vids on tiktok. do not even lie to me, also one of the most variated in flora and fauna oceans due to it's large extension. This is the home of the apex predator, a type of merfolk that mainly hunts and is known to drown sailors more than once the 'siren' genotype mermaids whom have almost hypnotic signing!

[catboybiologist]

can you elaborate on why some animals can self fertilize but it's bad for lots of animals to screw their siblings?

This has been sitting in my ask box forever bc I just keep forgetting to answer it LOL

Imma roll back to some basic genetic principles for this one, many of y'all will probably already know a good chunk of this.

If you remember your Mendelian genetics, you'll know you have two copies of every gene. Those genes come in forms called "alleles". The different alleles in a population are responsible for variation within that population, as each allele causes a different version of that trait. Now practically, a "trait" here is some deeply rooted biochemical concept that is extremely difficult to be visible in the organism overall because its linked to a million different signaling processes that will get obscured by it. The most strictly Mendelian example in humans that everyone knows is probably A/B/O blood type (I'm beating the horny people off with a stick if you read A/B/O differently). This is a great example because it also demonstrates the most common type of way that alleles can be recessive. Put simply, A and B are genes that code for functional proteins. O codes for a nonfunctional protein, and therefore is a lack of a protein. This is why someone that is genotypically AO has an A blood type overall, whereas AB is it's own distinct blood type. The recessive gene codes for nothing, the dominant gene codes for something, and the cell just produces a bit more off of the "functional" version (sometimes. broad generalizations all around. There are dominant loss of function genes but they're rare.). So to actually have an O blood type, both copies of that gene need to be O. Why is this relevant? Well, in blood type, the nonfunctional version of the gene doesn't affect the body really in any way, other than immune system reactions during transfusion. This is also the case with many other recessive genes. But for many, MANY genes, having a nonfunctional version is a genetic disease- something in the cell that needs to happen, or be built, isn't happening. But remember, you need to have both copies of the nonfunctional version of the gene for the gene's function overall to be nonfunctional.

So why are these genes still in the population? Well, their frequency is too low to be a problem most of the time, so there's really no selection pressure for them. Occasionally, you'll get a "disease" allele that happens to be useful in a different situation. The classic example is of course sickle cell anemia, which increases resistance to malaria. But these situations are rare. And of course, evolution happens over changing circumstances, so the selection pressure for a particular gene to be functional might just vanish before the opportunity for it to be bred out of the population arises, and the gene simply disappears from the species overall (looking at you, L-gulono-γ-lactone oxidase).

So those genes are lurking in your genome. You're probably carrying multiple recessive genes that, if you had both copies, would cause debilitating or fatal disease. Its just kind of a fact of the human condition. If you produce offspring with a random person, its highly likely that they won't carry the same nonfunctional genes as you, and your offspring are less likely to get both copies. That random mated partner will give their own set of random nonfunctional genes, but again, its likely they won't be the same as your set. But, if you produce offspring with someone genetically closer to you, the probability of that offspring getting both copies goes up, since that mate is more likely to have the same set of nonfunctional alleles as you.

So that's why inbreeding sucks. But other animals do it all the time- sometimes within family units, sometimes even via self fertilization and/or some other mechanism of parthenogenesis. What gives? There are two reasons why inbreeding could be okay in a given population of organisms, and they're kind of the opposite of each other: 1, the genetic variation in the population is so low, and has been through so many harsh evolutionary bottlenecks that there are very few deleterious mutations left in the genome. Sometimes, these organisms will be homozygous at every locus, meaning that different combinations of two different alleles is impossible. This is the extreme case, but humans have created exactly this organism- the lab N2 strain of C. elegans. This is horrible for a species long term, however, since you're essentially stalling gene flow between populations, meaning that all future natural selection has to happen on literally the same lineage of organisms from a single parent. These species are rare and tend not to be adaptable to long term change- many will have the ability to cross fertilize, and just do so on rarer occasions than most other organisms.

2, the genetic variation of the population is so high that the probability of finding a mate with the exact same deleterious mutation as you is very low, especially for multiple genes at once like humans get. Similar to the other situation, this can't hold up long term, because multiple generations of inbreeding will slowly increase the frequency of certain alleles in the population over time- but with some gene flow and/or careful mate selection, its possible.

Humans are at the messy little sweet spot between these two. Our genetic variation is incredibly low when compared to similar complex chordate species (thanks, pleistiocene population bottleneck), but we still have enough variation kicking around for those pesky mutations to still be here. Additionally, we're a species that cares for each other more intensely than most others, and uses social units to compensate for the entire group. So one or two individuals over the years with a genetic disease will survive, and pass that on. This is a good and incredible thing about the resilience of our species, so if you're gonna be weird about using evolution as morality you can gtfo.

So uh... yeah. Hope that answers your question! Now go play the Coffin of Andy and Leyley to answer any other questions you may have about incest.

[script-a-world]

Hello! I am building a scifi setting, and in this setting there aren't really any known planets besides Earth that would naturally support life (not human life, anyway), but over hundreds of years humans have terraformed several planets to support life in order to build settlements there, and that has included introducing plants and animals from Earth to those planets (my understanding is that terraforming, at least on this sort of degree, isn't really likely to be practical in real life, but that's something I am willing to handwave and go "it works because i say it works, just trust me bro" on).

Once that is done, the wild animals and wild plants brought over to a terraformed planet generally speaking are never transported from one planet to another again, although domestic animals, plants that are farmed, and humans themselves, might be. And I can see insects and microbes getting inadvertently transported from place to place among different kinds of cargo, since they're small enough to escape notice (I mean, the most venomous spider species in my country is a population of spiders that exists in one natural history museum because there were some accidentally brought over in a shipment of stuff from South America in the 60s or so. I can well see that happening on a planetary scale in a scifi story, too - but anyway)

My question is, if you have a population of animals that's isolated from other populations of the species to that degree, how quickly do you start seeing clear differences in the traits that different populations have? Like I don't expect to have entirely different species yet in a matter of centuries, but if you have a population of, say, roe deer, that would have been entirely isolated from other populations for like five hundred years, could there be differences between that population and other populations that a layman might be able to spot?

Tex: If everything’s on the same planet, it’s going to be difficult to truly isolate an area or population, because it’s going to be affected by the same planetary conditions, such as orbit around the nearest star, the ocean and its environment, etc.

Darwin’s finches, for example, have distinct variations in phenotype despite being effectively the same species (a similar situation for the Galapagos tortoises), which shows that a species’ genotypes can still appear as different physical traits given different environmental stresses.

It’s difficult to tell when evolutionary changes occur, because this depends on not only the species, but the environmental changes, the speed of such changes, and how deeply they impact a species in question. There currently isn’t any research being done on evolutionary characteristics of animals and their niche environments that I know of which has already been occurring for a hundred or more years, as much of our current generation of science is relatively recent given the scope of technological evolution.

Taking a look at the niche environment, how it differs from the originating environment (if this is part of the equation), how the two differ, and what environmental pressures are exerted would be a good start in extrapolating how phenotypic expressions might be altered without delving into the much more complex subject of epigenetic changes.

Utuabzu: Gravity, levels of light, the colour of the star, the length of the year and day and the degree of axial tilt are all going to have to be adapted to, since there's not that much that can be done about them. Organisms that evolved seasonal behaviours are going to lose those after a while on a planet with negligible axial tilt and thus negligible seasons. Organisms on tidally locked planets are going to lose traits dependent on a day-night cycle. Organisms on a high-gravity planet will get stockier, while those on a lower gravity one will get taller and thinner.

Photosynthesis is dependent on the interaction of a photosynthetic pigment with certain wavelengths of light. The dominant photosynthetic pigment on Earth is chlorophyll a, which reflects away the wavelengths we call 'green' and absorbs most of the rest of the visible spectrum. One theory for why it's dominant is that because the sun's emissions peak around the green part of the spectrum, this protects the photosynthetic organism from getting burnt - one point in favour of this is that non-chlorophyll a using photosynthesizers tend to favour shade. But around a different star, or even further out in our own solar system, chlorophyll a might not be ideal, and plants that use other proteins would reflect different spectra of light, and thus appear different colours.

But in terms of evolutionary timescale, it depends on generation length. Things evolve based on mutations that offer some benefit to the offspring of the mutant, leading them to be more successful than their peers and have more offspring in turn, which then are also more successful than their peers without the mutation and thus spread it through the genepool. A civilisation that can terraform planets on a reasonable timescale can almost certainly use genetic engineering as a shortcut to ensure their new biosphere can thrive immediately.

So you have a fair bit of leeway in terms of what you can do with other planets' biospheres. Terraforming on a scale shorter than thousands of years would already take technology well beyond anything we have, so you can handwave a fair bit.