Mendel is not wrong. He knew full well what the limits of his theory were. He had to assume the ideal case, because that is all he could observe with 1865's biology knowledge. Without DNA tests, he was limited to traits that he could: 1. Observe with a Mark 1 eyeball 2. That were inhereted independantly and by a single allele The peas he grew in his garden just happened to fit both requirements for their color genes.
Important to note that the pea colors Mendel used to differentiate genes didn't come from a single or few alleles. Pea colors come with a lot of in between and even mixing in the same pea. Mendel did a lot of selection pressure to have clearly defined colors, which probably came from a lot of alleles that he managed to group together. There's a lot that's updating in genetics I recommend checking it up because it's really interesting and Mendel does fall short in some of the essentials.
Not related to the topic, but point form that continues a sentence should end at the last word shared by all the points to avoid redundancy, followed by an ellipsis. In your case, it should look like this: "Without DNA tests, he was limited to traits that... 1. he could observe with a Mark 1 eyeball, and; 2. were inherited independently, and by a single allele." It's also nice to follow intermediate points with a conjunction and semicolon like I did there, but isn't necessary like avoiding redundancy is.
@@monicarenee7949 I'm just trying to be helpful. Since my partner (ESL) likes when I correct her on things like that, I try to keep in mind that not everyone on the internet is 100% fluent in English. Maybe it was just a mistake, or maybe I can help someone improve their English with a quick comment. I don't see that as a bad thing.
Lol, honestly I didn't know what the birds and the bees meant until 6th grade😂 I grew up on a farm and knew how reproduction worked very early in life lol
I just finished my honours in evolutionary biology specifically looking at taxonomy in a group of marsupials and one of the main takeaways I have is that 'species' don't really exist in an objective sense. We can define it in whatever way we like but there will always be exceptions and some degree of arbitrariness, because evolution ultimately isn't trying to _create_ species (in the sense of discrete units of life).
Indeed. The unit of evolution is the population. Species is something we try to impose to make things simpler for us, that mostly works. Which marsupials did you work with?
@@b.a.erlebacher1139 Populations can have pretty fuzzy boundaries, too. They're handy analytically, but once you get out in nature, good luck defining exactly where one population ends and another begins.
"Species" are a useful approximation of reality. A hack, you might say. A heuristic. They make it easier to talk about nature, right up until you start looking really closely, and they made it harder.
Genetic compatibility is ONE aspect of how a species may be described. In fact, the cat example in the video is counter to this definition, because Felis catus can have fertile offspring with Prionailurus bengalensis. Especially among plants, there are "species continuums" everywhere, in Salvia, Quercus, all over Orchidaceae etc.
That’s more an issue with taxonomy than genetics, if two species can reproduce then genetics said yes but taxonomy doesn’t necessarily have to because it has its own set of rules which itself is another debate.
@@dreammaker9642 Essentially at a genetic level, wolves, dogs, foxes and jackals are the same species as they all can crossbred and the offspring is fertile
@@diablo.the.cheateryour right about dogs wolves and jackals, but a true fox cannot crossbreed with any of them. Their chromosomes are not compatible . Also worth noting that dogs are considered subspecies of wolves nowadays (canis lupus familiaris) but really all the wolf-like canids can interbreed just fine so it’s a bit arbitrary to call them different species. But keep in mind it’s just about if they can interbreed, but if they do interbreed. Animals that are genetically compatible can still be reproductively isolated in other ways (behavior geography etc) meaning they can be seen as different species.
@@Leadvest but given there are things we still don't quite understand 100%, wouldn't that by nature mean it could theoretically still have an exception we just haven't found yet? I mean until we know everything about the universe, wouldn't that be the case? I do get your point though, because there's been nothing that even hinted that's a breakable set of facts.
Hank is a sicko who gets off on torturing animals with toxic chemicals and disease. That's what science is about, Hank taught me that a few years ago. That's all science is : torture of the weak and defenceless.
That’s why taxonomy changes, it’s not static but it takes a bit more than genetics too. Also usually when you make interesting findings it’s more efficient to investigate them further and only change once you’re sure it’s more fitting than switching at the first sign of doubt and spending your time switching things around. I mean it’ll keep you busy but would also be counter productive but good science take time.
@@dreammaker9642i used to want to be a taxonomist cause I love animals but then I realised the truth : biology is about torturing animals in mad science experiments infecting them with disease. That's the essence of biology. Biologists who don't torture animals still support it they all know that's what biology is about.
OMG I love Penstemons! I've been planting every kind I can find! I think my favorite varieties are Barrett's and Beautiful, but I love Foxglove and Firecracker too. So much variety! I didn't realize the genetic labyrinth behind the scenes of those gorgeous flowers.
It is highly likely that the other crosses don't service long enough to find different pollinators. Re-assotation may be aided by especially weak spots near these geans. That could be the mutation in and of itself.
Practically all stapeliads will hybridise if artificially pollinated. They have no chemical barriers to crossing with other species because they are specialised to particular flies so seldom get crossed with other species in nature. The flowers smell of different rots or corpses, often with exactly the chemicals that those rots produce. There is even one near the coast that has nature-identical rotten fish odours.
Ok..... So..... I've just spent the last 5 minutes watching the 2 bee's run into each other at 1:35. Now I have to watch the video all over again and pay attention to the flowers.
I won't put this against Mendel. The guy only had peas to work with. To cook up a whole theory that applies to the enormous number of species on earth is quite an achievement.
Actually having freeflow inheritance might actually be why they can still hybridize. The more genetic traits that clump together I harder it would be to be genetically compatible to hybridize. Think of it like a working computer and a phone made out of legos. You would be able to swap practically every part and still function. But if they had custom parts made then you wouldn't be able to do that, even if just a really small part. What these flowers have done is come up with a system that allows for genetic modularity, a first to my knowledge. Some things I'd be curious about in the future: How far was their last common ancestor? Is their genetic difference greater, equal to, or less than that of other plant species and subspecies? Is there some hidden mechanism that allows certain genes to uncouple and, using your highway example, broadcasts a sign for all the cars to head to the same destination? I'm really excited to see where things are headed here. Please keep us posted if any new info comes out about this! Interesting how this came out after the Gar genetic stall, and the hybridization of the sturgeon & paddlefish a few years back. Still seems like there are underlying forces and rules governing genetics that we still have yet to understand.
@@TheRealSkeletor It's one of life's great mysteries isn't it? Why are we here? I mean, are we the product of some cosmic coincidence, or is there really a God watching everything? You know, with a plan for us and stuff. I don't know, man, but it keeps me up at night.
The same is true in fungi: genetics shows that many species we thought were distinct are actually single species and the taxonomy is changing constantly
Nature definitely does not like to be confined into neat little boxes, no matter how much some of humanity want it so. Dogs will breed with wolves and coyotes... Pugs and Malamutes are somehow the same species... Nature is complex and messy and I love it.
This video made me appreciate nature's complexity even more. It's surprising how these beardtongues are revolutionizing our understanding of genetics. Eager to learn more about how species adapt to environmental changes!
@SciShow This the concept of a "functional locus" which can be a single QTL (Quantitative Trait Locus) region or it can be widely distributed throughout the genome. One theory of why this is so common in plants is that it is due to "paleoploidy" (or paleo-polyploidy if you prefer). Gene regions duplicate due to ancient polyploids that revert back to diploid populations with duplicate gene regions shuffled in the genome. These duplicated regions diverge over many generations due to mutation, so a plant winds up with many regions throughout the genome that are related in function but are slightly different. Polyploidy is not very common in animals (Daphnia being a notable exception) so this is perhaps not quite as common in animals, although there all other potential mechanisms. We know independent assortment is not true, that hypothesis has been utterly disproven. Chromosomes are inherreted in units. Even crossover events are not random and tend to occur in specific regions of chromosomes. This how we can define QTL regions in the first place, linkage disequalibrium can be statistically detected because regions of the genome are consistently coinhereted.
Well, the only issue with this is that bees are one of the pollinators of the blue version of this flower. This makes me think that a pressure other than just color is keeping bees interested in just the blue flower, probably scent. Bees would be able to see the purple variant as a possible food source, but they might not be interested if it doesn’t smell right to them. Assuming the color would change, the smell probably would as well since the genes are all connected to the plant’s specific pollinators. There doesn’t seem to be any pollinators that can both see red and blue, so it’s unlikely that there was ever a pollinator for the hybrid version that was specialized for the purple hybrid plus the other two red/blue parent plants. The only reason I can think of for the hybrids is accidental pollination from one of the pollinators by running into/past the other color or by wind.
I think it's the opposite, based on how it was explained. A new species will emerge (AKA the hybrid purple) once a compatible pollinator happens to stumble on a group of the hybrid.
@@PhailRaptor Yes, however that’s unlikely when the existence of the purple variety hinges on happenstance and doesn’t exist at all times the plant parents do.
I'd be curious to know if there isn't potentially a third pollinator that the different red and blue variants don't rely on and which only intermittently interacts with them both, but enough such that it mediates genetic drift
@@TheGroundedCoffeeI think youtube does that all on its own. I saw the tag with the 🔎 symbol next to it, but then when I tapped the comment to see the response (your comment), it disappeared.
@@Name-ot3xw the word combo "peppermint shrimp" got displayed as hyperlink (blue) and had a magnifying glass symbol behind it. I could click on it and it sent me to the TH-cam search page where peppermint shrimp was displayed as the results of a search.
Growing up, I always pondered where one species ends and the other begins. And I also wondered similar thoughts about all levels of classification, be it genus, family, class, phylum, kingdom, etc. Groups often tend to branch out into new groups. Then you wind up with a tiktaalik situation, where you have an animal that sort of falls into two groups. But species are an especially finicky technicality it seems. Such a fun subject to delve into!
The desert Parrys version of this plant have different "races" of slightly different shades, while being in the same habitat. They come in magenta, coral, and rose pink. All on their own, while maintaining their hummingbird feeders.
Species: the part of taxonomy where if no one else has named it, you get to name it. Since no two individual anythings are exactly the same, there are an infinite number of potential species.
Everytime they find something that makes us different from each other, there are countless other things discovered or hidden, that makes us all the same with "very few differences, but infinite variation."
Plant speciation is really weird. Like the dozen or so pistacia species in the Mediterranean and then theres one or two lone weirdo species native to north america that still seem to be both graft and cross compatible with the mediterranean cousins
Mandel was more right than Lamarck, but they were both kind of wrong, and we forget often that Mendelian genetics concern selection on traits directly. It wasn't monogenic expression, with single genes producing single traits, but rather traits were directly inherited. Only later were genes imagined to be specific kinds of physical objects. Most of the history of science is like this, with really progressive work also featuring profound incompletenesses or inaccuracy. Who we see as progressive but incomplete, and who we see as informative but discredited, is most often the product of later narration of past events. I think it's important to understand science as an incomplete process where few ever manage to be "right" in any final sense. Some fortunate and industrious few just manage to push our knowledge forward.
I believe the reason Mendel is still taught today is because learning Mendel makes learning the more up-to-date theories easier, and Mendel's work still makes some useful predictions. You see this a lot in science. Pre-quantum mechanics models of the atom are still taught in chemistry. Lewis structures are still pretty common in some areas of chemistry, and even when they were developed in 1916, they were a gross simplification rather than a rigorous model. They just happen to be a very useful gross simplification. I believe Mendel was aware that colour and texture of peas were unusually simple compared to most inherited traits, but that was why he chose them to work with. They allowed him to work out general principals using the technology he had available to him.
I don't see why this is controversial: the hummingbirds and pollinating insects are the environmental drivers of flower morphology, hence those individual plants from seeds with the full complement of genes for bird-favourable features will produce more offspring and out-compete those plants that half-arsed it by being intermediately favourable to either birbs or bugs; similarly those plants from seeds with the full complement of genes for pollinating insect-favourable features will also leave more offspring than those that failed to be fully favourable to bugs or birbs. This probably happens at a lower rate than when genes are shared due to being in proximity on chromosomes, but the benefits to reproduction in the individuals with the specialised genomes are probably great enough that inheriting the full complement of genes for either specialised phenotype offsets the lower rate at which physically distant genes are inherited together as a group. What would be interesting would be to conduct some experiments to see if any of the relevant genes move locus to become closer to each other over time, increasing the rate of production of individuals with the full complement of genes for highly specialised flowers.
The difficult or controversial part is how the different loci are linked eventhough they are not located on the same chromosome. So how can they be inherited together
This reminds me of the TNG line at the end of the episode with Troi’s star baby about how part of the beauty of scientific discovery is that we can’t discover everything.
Please correct me if this has already been discussed, but in response to this I would love to hear your presentation on the genetics of reptiles. Morphology in individual species is insane in the private hobby, and hybridization would be a great thing to discuss here. Anaconda species have produced viable offspring with redtail boas (boaconda). Baboon viper and Rhino viper (Gabino viper) hybrids are well known, and ball pythons have produced hybrids with Burmese pythons among a myriad of other species. Idk which hybrid offspring are viable for reproduction off hand, I'll do some research and add later, but it would be interesting to discuss the genetic factors that define species and what can reproduce with what in the different herp families
Got something already. Aspidoscelis neavesi is a hybrid species that ended up reproducing through parthenogenises, which seems to be fairly common in lizards and other odd occurrences in reptiles
Hank, Maybe plants have something like genetic barrier-carpool-lanes, so they have to travel together (due to something as yet undiscovered). I haven’t taught biology since 1993-4, so I’m darn rusty on some already outdated understanding. I’ll pass this on to my colleagues and students in case anyone’s feeling like a career in botanical genetics!
Perhaps it's a survivor bias issue. Hypothetically perhaps only the seeds that inherit those genes as a group are viable, therefore you'd only see plants that inherited those genes together.
One potential explanation is that while unlikely, for each gene in each of 21 loci, there are highly selected for genes that are codependent. In other words, you will never see plants without all 21 inherited as those offspring are not/are less viable.
I mean miotoc drive breaks Mendel’s law of equal segregation so I could see a polygenic sort of miotic drive doing something similar during polen formation for those 21 variants. If indeed it’s simply strong selection the S value would be truly INSANE and higher than anything we see in animals.
4:09 I want to! I really really do want to do my PhD in genetics (plant or otherwise) but a lack of time and money get in the way of me going back to school 😭
A lot of universities have grad programs almost completely comped by the program for this sort of science if you are doing research and work as either a TA or research assistant, as well as additional fellowships and grants. That doesn't help the TIME part but may ease the financial part a little, if you were unaware.
In plant breeding we usually cause the formation of favourable haplotypes containing genes that aren't that close together. Actually it's not uncommon to see linkage disequilibrium among markers in different chromosomes due to selection pressures, be them natural or not. Source: seen it myself, PhD candidate in plant genetics
I believe what you’re describing is more a syngameon, not a species complex. A species complex is when two or more species are virtually indistinguishable, such as in the coral Fungia fungites.
No, a syngameon is defined as a group of organisms that hybridise frequently causing a lot of gene flow due to the weak reproductive barriers. However, in this Penstemon spcies there are reproductive barriers caused by the differenr pollinators what makes hybrids very rare
Re: pronunciation of "loci" -- in Latin, the letter C is always a hard consonant; it was the Roman equivalent of the Greek letter Kappa. Also, the letter I was a long vowel, pronounced like "ee" is in English. Basically, the word should be pronounced like Tom Hiddleston's most popular character.
'LO-KEE is a valid pronunciation of loci, but so are 'LO-KAI and 'LO-SAI (all according to Meriam-Webster). 'LO-KEE would indeed be pronunciation in ancient Rome, but the pronunciation of Latin has changed a lot since then. The Wiktionary article for loci references the article for foci, which states: 'Both the "hard C" and "soft C" pronunciations are accepted. Although focus has C followed by a non-frontal vowel and is thus universally pronounced with a "hard C", there is a grey area for pronouncing the plural form foci. Under normal orthography rules, the C should be transmuted due to it being followed by one of the three frontal vowels (e, i, and y), but the "hard C" pronunciation is also valid due to this word being the plural of a word that is strictly pronounced with a hard C.'
That is the correct pronunciatio restituta pronunciation. At the same time, most schools in Europe teach Latin in the medieval church Latin pronunciation, so (for example) the c in pronunciatio is not a k sound but a ch sound, and the t is a ts sound instead of a t sound, to an European student Ultimately, both pronunciations (restituta and medieval) are considered valid
'Low-sigh' is correct according the traditional English pronunciation of Latin, which evolved just as naturally as every other regional Latin phonology. The fact that the English pronunciation has gone out of favour outside of scientific circles in the last 120 years doesn't make it wrong. You can no more say that any one Latin phonology is wrong than you can say that American phonologies of English are wrong. They're just different.
All it will take now is another insect pollinator to be discovered that simply loves the colour red and need a landing pad, or a tiny bat that is attracted to ultraviolet light and wants to hover and stick its tongue into a tubular flower.
so to use the bus analogy it is like a bunch of people getting off at the city centre. while technically chances should be equal, there is an outside incentive to get off *there,* an additional benefit that makes it more likely
I studied Molecular Genetics in the mid-80's [made lots of electrophoesis gels] when DNA identification was getting recognized as forensically viable. One of the basic actions of gene expression from DNA that I don't see mentioned much, is that the DNA is tightly coiled and specialized proteins/RNA will open up a section that is to be read. ie all of the DNA nor even a strand of a chromosome are ever fully opened and copied [except for regeneration - eggs & sperm - which is not for gene expression to make proteins]. DNA has several subfunctions, not just protein manufacture. It has sections that code for opening up sections to be replicated, opening code doesn't necessarily have an associated protein or RNA. It's basically the order to make something because . . . there's too much of something, too little of something, something needs regeneration, something needs to stop. Some cancers are because these coding areas forget to turn off. But what I am getting at is that most 'code', ie DNA segments, stay dormant until needed. Such as people are shorter when food is seasonally scarce - we get taller when food is abundant. And for most species we don't know what triggers the changes. [one that fascinates me is domestic pigs have sparse hair, but when they go feral, they get furry in one or two generations].
Hank, I discovered the mind blowing world of plant taxonomy recently. Here’s some things that deserve a video: 1. Kale, broccoli, cauliflower, brussel sprouts, cabbage, and kohlrabi are all the same species. 2. Citrus taxonomy is absolutely nuts - they hybridize very easily, and the ancestry of the lemon is complex criss-cross of mandarins, pomelos, and citrons. 3. “Tree” is not a taxonomic category - nor is “nut”, nor “berry”. These are forms that have resulted from the convergent evolution of vastly different plant lineages. An apple tree is more closely related to an almond tree, a blackberry bush, and a rose (Rosaceae) than a Brazil nut tree and a blueberry bush (Ericales) or an orange tree, a cashew tree, and poison ivy (Sapindales). Finally, a grab bag of weirdly closely related plants: Spinach n’ Tumbleweeds (Chenopodiaceae). Eggplants n’ Tobacco (Solanales). Hops n’ Hemp (Cannabaceae). Bananas n’ Cardamom (Zingiberales). Cinnamon n’ Avocado (Lauraceae). And finally, Mapighiales (violets, flax, weeping willows, coca, ricin, cassava melons, and rubber).
I grew Penstemon of a number of cultivars for years and I never noticed who pollinated who. I love the image of the Anna's Hummingbird and the Bee great capture.
The word "species" is like the word "planet". It's a category that people invented. The universe doesn't have to always fit our categories, and just because if doesn't doesn't mean that the category is useless.
The word "loci" is the plural of "locus" (which comes from mathematics related to where things can be) and is pronounced LoKe-us with the hard sound in the middle. So loci is pronounced Loke-eye, not to be confused with Loki.
Just saying as an avid gardener and someone who works with plants, the hummingbirds here do not seem to care about color. They love all colors of penstemon, white, blue, red, or purple. In fact they’re favorite flower to visit in my experience actually seems to be black and blue salvia.
I wonder if there's some interesting selective pressures between dogs, wolves, and coyotes? All are capable of interbreeding with viable offspring, but are still counted as separate species for some reason. And generally there's a natural separation due to differences in behavior. So is there something similar going on with that group of mammals?
How is Mendel wrong? He never claimed anything to do with this, Mendel died in 1884, chromosomes weren't thought of until at least twenty years later. Apologize to poor Gregor.
He wasn't!!! He was looking at discrete patterns of inheritance in pea plants before we even knew what a gene or even the chromosome was! But yet, he recognized there must have been some factors of inheritance (he called these unit factors). Gregor was awesome! But we know now genetics is complicated beyond our wildest dreams!
My guess would be a methylation or some other structural "ID" (that could have epigenetic influence) would be at play, in which case they would likely have something in their centromere (centriole? Idk its been a few years since my degree, pls bear with me if this isnt the right term) structure which links and matches to these ID (probably protens?) during the division process to influence to which side of the cells the given genes are pulled Its alternatively also giving me the impression of some antibody type functionality which would normally be associated with learned immunities hijacked into the reproductive process realm ........ I got into a phd program in 2020 and bailed last second at the thought of moving back to nyc at the start of the pandemic.....maybe i should reconsider the career trajectory im on now and go back to my eco-evo bio roots and reapply to new programs 😅 My brain is seriously, seriously running on this with so many mechanisms that would be possible to cause this
To me it just shows living beings have adaptation imprinted into their genes. In one situation, certain genes become dominant, in others, others do. It doesn't mean those characteristics necessarily disappeared. It means that they are temporarily suppressed but stay in the dna.
When I was at uni 50 years ago we were taught that species is a shorthand not to get too hung up on. Life is a continuum' it's just that lots of the intermediates aren't around any more.
Life is weird; as an increasingly decrepit pensioner, I find the SciShow videos fascinating, whilst back in the good ol' days of highschool, I found all science subjects as interesting as watching paint dry.
I'd wager a lot of that change comes down to a) how it's presented and b) being able to choose interesting topics and see how principles apply to it! I know I never would have learned about these flowers in my bio classes!
Plants hold so many answers to questions we can't even think to ask. I wonder how different microbial colonies in a plant's soil might impact its biology.
This means a humming bird may take the nectar of a flower for the bees. And a bee may take the pollen of a flower for hummingbirds on rare occasions. Explaining this phenomenon as the two different flowers can mix their pollens rarely.
I remember studying Mendel in the 7th grade. It was fairly superficial and I feel now that perhaps my education was not what it could have been, but after all, it was 60 years ago.
There are at least 26 different definitions of what a species is that scientists have come up with. None of the definitions are perfect, because definitions try to make the world orderly, but nature insists on being messy.
OK so as a genetics graduate, here's my potential theory that could be investigated There could be interactions between the products of these genes that promotes the success of individuals which inherit them together, or perhaps interactions between the genes in hybrids that mean a large number of them aren't viable?
Huh, I wonder if you could artificially continue to breed hybrids would the 21 loci continue to divide as a group? That would test the theory if whether selection pressure is the only driving force or if there was something else?
Doesn't explain white and off-white Penstemon, like eastern species P. digitalis, P. calycosus, both hummingbirds and bees pollinate both. Also, Chelone obliqua is pollinated by both hummingbirds and bees, and is white, sometimes with a light blush. These are all native eastern plants. Also, Mimmulus ringens, which is blue-purple and hummingbirds love. The real answer is not as simple as you think. There's more going on. We just haven't figured it out yet.
I think there is a master gene set at one locus that determines the final type by switching the rest of the genes on or off. But it also verifies it has a complete set of the necessary genes for its type and dies if it doesn't. Mutants have a version of the master genes that do not correctly check for every gene needed, and the mutant lives on but has a more difficult time passing on its mutant genes.
That was neat and all and it makes sense why hybrids aren't sustainable and don't reproduce together like bee flowers or bird flowers do. But I'm not sure how this would make Mendel wrong in any way. I don't think he ever posited that all related traits have to be located near each other in the same chromosome. My understanding is that he was more observing how two independent traits tend to get passed down together if they are on the same chromosome. I dunno. I might be missing something. But I kind of doubt the fact that a hybrid not necessarily being able to compete and thrive against regular flowers that are specialized to take advantage of a specific niche really breaks anyone's understanding of genetics.
I don't quite understand the conundrum presented. The flower color and shape are connected to the flowers' pollinator. Crosses are essentially selected against because they don't attract either pollinator and the color/shape flowers are perpetuated. We find plenty of plant and pollinator symbiotic relationship in nature. In some cases, the two have become so dependent on one another that the extinction of one would lead to the extinction of the other. Selective pressures perpetuate the continued separation of these blue and red flowers of the same species because of the preferences of their respective pollinators. Over time, the genetics of these two varieties could diverge even more so they would be unable to reproduce together and hybridize - much the way horses and donkeys have.
Mendel is not wrong. He knew full well what the limits of his theory were.
He had to assume the ideal case, because that is all he could observe with 1865's biology knowledge. Without DNA tests, he was limited to traits that he could:
1. Observe with a Mark 1 eyeball
2. That were inhereted independantly and by a single allele
The peas he grew in his garden just happened to fit both requirements for their color genes.
Important to note that the pea colors Mendel used to differentiate genes didn't come from a single or few alleles. Pea colors come with a lot of in between and even mixing in the same pea. Mendel did a lot of selection pressure to have clearly defined colors, which probably came from a lot of alleles that he managed to group together. There's a lot that's updating in genetics I recommend checking it up because it's really interesting and Mendel does fall short in some of the essentials.
Not related to the topic, but point form that continues a sentence should end at the last word shared by all the points to avoid redundancy, followed by an ellipsis. In your case, it should look like this:
"Without DNA tests, he was limited to traits that...
1. he could observe with a Mark 1 eyeball, and;
2. were inherited independently, and by a single allele."
It's also nice to follow intermediate points with a conjunction and semicolon like I did there, but isn't necessary like avoiding redundancy is.
@@Kwauhn. or…OR…it’s just a TH-cam comment and not a scientific paper.
@@monicarenee7949 I'm just trying to be helpful. Since my partner (ESL) likes when I correct her on things like that, I try to keep in mind that not everyone on the internet is 100% fluent in English. Maybe it was just a mistake, or maybe I can help someone improve their English with a quick comment. I don't see that as a bad thing.
Lol "mark 1 eyeball"
So this was the birds and the bees talk my parents were talking about... weird.
Lol, honestly I didn't know what the birds and the bees meant until 6th grade😂 I grew up on a farm and knew how reproduction worked very early in life lol
@@WhataMenschAre you okay?🤡🤡🤡🤡
@@WhataMenschI hate the IDF too but I don’t know about “science bombs”.😂😂🤣🤣
@@WhataMensch That sounds a lot like what a bot would say 🤔
@@WhataMenschspeak plainly.
You'll find an audience who actually speak your language.
Instead of the teeming unwashed masses who do not.
I just finished my honours in evolutionary biology specifically looking at taxonomy in a group of marsupials and one of the main takeaways I have is that 'species' don't really exist in an objective sense. We can define it in whatever way we like but there will always be exceptions and some degree of arbitrariness, because evolution ultimately isn't trying to _create_ species (in the sense of discrete units of life).
Duck billed platypus
Indeed. The unit of evolution is the population. Species is something we try to impose to make things simpler for us, that mostly works. Which marsupials did you work with?
@@b.a.erlebacher1139 Populations can have pretty fuzzy boundaries, too. They're handy analytically, but once you get out in nature, good luck defining exactly where one population ends and another begins.
"Species" are a useful approximation of reality. A hack, you might say. A heuristic. They make it easier to talk about nature, right up until you start looking really closely, and they made it harder.
@@clawsoon Yes, the real world is a very messy place! :-)
1:47 Tell whoever did the art that they did a good job!
Yea, these animations are awesome. That artist/editor deserves a raise.
The art is gorgeous!
The animations are stunning! But I think they drew the wrong plant. Looks like Digitalis (foxglove) rather than Penstemon (beardtongue.)
@@RitaMannaI agree but also I’ve tried to illustrate penstemon, and it’s so hard to get their shape exact 😅
@@RitaMannayes possibly because the penstemons are called beardtongue foxgloves, but are not true foxgloves of the digitalis genus.
Genetic compatibility is ONE aspect of how a species may be described. In fact, the cat example in the video is counter to this definition, because Felis catus can have fertile offspring with Prionailurus bengalensis. Especially among plants, there are "species continuums" everywhere, in Salvia, Quercus, all over Orchidaceae etc.
That’s more an issue with taxonomy than genetics, if two species can reproduce then genetics said yes but taxonomy doesn’t necessarily have to because it has its own set of rules which itself is another debate.
@@dreammaker9642 Essentially at a genetic level, wolves, dogs, foxes and jackals are the same species as they all can crossbred and the offspring is fertile
@@diablo.the.cheater yes but taxonomically they are not, there’s more that goes into a species than just genetics.
yes it's where humans have arbitrarily decided to delineate them@@dreammaker9642
@@diablo.the.cheateryour right about dogs wolves and jackals, but a true fox cannot crossbreed with any of them. Their chromosomes are not compatible .
Also worth noting that dogs are considered subspecies of wolves nowadays (canis lupus familiaris) but really all the wolf-like canids can interbreed just fine so it’s a bit arbitrary to call them different species. But keep in mind it’s just about if they can interbreed, but if they do interbreed. Animals that are genetically compatible can still be reproductively isolated in other ways (behavior geography etc) meaning they can be seen as different species.
The only immutable law of nature is that there will always be an exception to any law of nature we can define.
With some of the important exceptions to that rule being the laws of thermodynamics.
Biology and softer science mostly don't have laws because they're so random, unlike Physics. This phenomenon has its own term- Physics envy.
@@Leadvest but given there are things we still don't quite understand 100%, wouldn't that by nature mean it could theoretically still have an exception we just haven't found yet? I mean until we know everything about the universe, wouldn't that be the case?
I do get your point though, because there's been nothing that even hinted that's a breakable set of facts.
@@goosenotmaverick1156 We literally can never know everything about the Universe.
I think there's an uncountably infinite number of things we can never know.
I heard Hank talk science today. Always a good thing
Hank is a sicko who gets off on torturing animals with toxic chemicals and disease. That's what science is about, Hank taught me that a few years ago. That's all science is : torture of the weak and defenceless.
'Species' are just the filing system for scientists, but it seems inadequate when nature is just endless adaptation.
Darwin: Part Deux
That’s why taxonomy changes, it’s not static but it takes a bit more than genetics too. Also usually when you make interesting findings it’s more efficient to investigate them further and only change once you’re sure it’s more fitting than switching at the first sign of doubt and spending your time switching things around. I mean it’ll keep you busy but would also be counter productive but good science take time.
@@dreammaker9642i used to want to be a taxonomist cause I love animals but then I realised the truth : biology is about torturing animals in mad science experiments infecting them with disease. That's the essence of biology. Biologists who don't torture animals still support it they all know that's what biology is about.
OMG I love Penstemons! I've been planting every kind I can find! I think my favorite varieties are Barrett's and Beautiful, but I love Foxglove and Firecracker too. So much variety! I didn't realize the genetic labyrinth behind the scenes of those gorgeous flowers.
It is highly likely that the other crosses don't service long enough to find different pollinators. Re-assotation may be aided by especially weak spots near these geans. That could be the mutation in and of itself.
Thank you Hank for teaching us all about the birds and the bees.
Someone had to.
Less of a tree of life, more like a martini shaker of life.
The tree of life has flowers, and they cross pollinate more like.
Shaken or stirred?
Practically all stapeliads will hybridise if artificially pollinated. They have no chemical barriers to crossing with other species because they are specialised to particular flies so seldom get crossed with other species in nature. The flowers smell of different rots or corpses, often with exactly the chemicals that those rots produce. There is even one near the coast that has nature-identical rotten fish odours.
This is probably the BEST episode, so far!! I'm forwarding the scistarter link to every educator I know!! THANK you!!
0.0
“They say great science is built on the back of giants. Not aperture science!”
Climate crisis? Bye channel!
@@Anton-tf9iw Begone bot
"We do all our science from scratch"
Didn't expect to get the birds and the bees talk from hank today
Ok..... So..... I've just spent the last 5 minutes watching the 2 bee's run into each other at 1:35. Now I have to watch the video all over again and pay attention to the flowers.
I won't put this against Mendel. The guy only had peas to work with. To cook up a whole theory that applies to the enormous number of species on earth is quite an achievement.
Actually having freeflow inheritance might actually be why they can still hybridize. The more genetic traits that clump together I harder it would be to be genetically compatible to hybridize. Think of it like a working computer and a phone made out of legos. You would be able to swap practically every part and still function. But if they had custom parts made then you wouldn't be able to do that, even if just a really small part. What these flowers have done is come up with a system that allows for genetic modularity, a first to my knowledge.
Some things I'd be curious about in the future: How far was their last common ancestor? Is their genetic difference greater, equal to, or less than that of other plant species and subspecies? Is there some hidden mechanism that allows certain genes to uncouple and, using your highway example, broadcasts a sign for all the cars to head to the same destination? I'm really excited to see where things are headed here. Please keep us posted if any new info comes out about this!
Interesting how this came out after the Gar genetic stall, and the hybridization of the sturgeon & paddlefish a few years back. Still seems like there are underlying forces and rules governing genetics that we still have yet to understand.
Hank: So the reds and the blues stay separate....
Me: The Bloods and Crips of the flower world.... 🤣
😎
Do you ever wonder why we're here?
@@TheRealSkeletor It's one of life's great mysteries isn't it? Why are we here? I mean, are we the product of some cosmic coincidence, or is there really a God watching everything? You know, with a plan for us and stuff. I don't know, man, but it keeps me up at night.
But occasionally West Side Story happens.
@@clawsoonDarwin starts snapping his fingers.
The same is true in fungi: genetics shows that many species we thought were distinct are actually single species and the taxonomy is changing constantly
My immediate first thought as a molecular biologist is epigentic involvement. Super interesting!
Nature definitely does not like to be confined into neat little boxes, no matter how much some of humanity want it so. Dogs will breed with wolves and coyotes... Pugs and Malamutes are somehow the same species... Nature is complex and messy and I love it.
This video made me appreciate nature's complexity even more. It's surprising how these beardtongues are revolutionizing our understanding of genetics. Eager to learn more about how species adapt to environmental changes!
@SciShow This the concept of a "functional locus" which can be a single QTL (Quantitative Trait Locus) region or it can be widely distributed throughout the genome. One theory of why this is so common in plants is that it is due to "paleoploidy" (or paleo-polyploidy if you prefer). Gene regions duplicate due to ancient polyploids that revert back to diploid populations with duplicate gene regions shuffled in the genome. These duplicated regions diverge over many generations due to mutation, so a plant winds up with many regions throughout the genome that are related in function but are slightly different. Polyploidy is not very common in animals (Daphnia being a notable exception) so this is perhaps not quite as common in animals, although there all other potential mechanisms. We know independent assortment is not true, that hypothesis has been utterly disproven. Chromosomes are inherreted in units. Even crossover events are not random and tend to occur in specific regions of chromosomes. This how we can define QTL regions in the first place, linkage disequalibrium can be statistically detected because regions of the genome are consistently coinhereted.
Mendel can have an incomplete understanding without nessessarily being wrong
Now what if they used to hybridize but the pollinator went extinct before we even realized what was going on
That's entirely possible.
I find this an intriguing possibility. Could be worth a grant from NSF
Well, the only issue with this is that bees are one of the pollinators of the blue version of this flower. This makes me think that a pressure other than just color is keeping bees interested in just the blue flower, probably scent.
Bees would be able to see the purple variant as a possible food source, but they might not be interested if it doesn’t smell right to them. Assuming the color would change, the smell probably would as well since the genes are all connected to the plant’s specific pollinators.
There doesn’t seem to be any pollinators that can both see red and blue, so it’s unlikely that there was ever a pollinator for the hybrid version that was specialized for the purple hybrid plus the other two red/blue parent plants. The only reason I can think of for the hybrids is accidental pollination from one of the pollinators by running into/past the other color or by wind.
I think it's the opposite, based on how it was explained. A new species will emerge (AKA the hybrid purple) once a compatible pollinator happens to stumble on a group of the hybrid.
@@PhailRaptor Yes, however that’s unlikely when the existence of the purple variety hinges on happenstance and doesn’t exist at all times the plant parents do.
I'd be curious to know if there isn't potentially a third pollinator that the different red and blue variants don't rely on and which only intermittently interacts with them both, but enough such that it mediates genetic drift
Hank out here bringing the og "birds and bees"
If you breed peppermint shrimp for enough rounds without culling they tend to stop producing red shrimp in favor of muddy brown.
Wait, how did you make that tag?
@@TheGroundedCoffeeI think youtube does that all on its own. I saw the tag with the 🔎 symbol next to it, but then when I tapped the comment to see the response (your comment), it disappeared.
@@vocalsunleashed yeah so weird. It's gone for me now as well.
@@TheGroundedCoffee I just made my name "name" and youtube put the stuff at the end. I dunno what tag you saw, to me it shows as @name-ot3xw
@@Name-ot3xw the word combo "peppermint shrimp" got displayed as hyperlink (blue) and had a magnifying glass symbol behind it. I could click on it and it sent me to the TH-cam search page where peppermint shrimp was displayed as the results of a search.
Growing up, I always pondered where one species ends and the other begins. And I also wondered similar thoughts about all levels of classification, be it genus, family, class, phylum, kingdom, etc. Groups often tend to branch out into new groups. Then you wind up with a tiktaalik situation, where you have an animal that sort of falls into two groups. But species are an especially finicky technicality it seems. Such a fun subject to delve into!
The desert Parrys version of this plant have different "races" of slightly different shades, while being in the same habitat. They come in magenta, coral, and rose pink. All on their own, while maintaining their hummingbird feeders.
Species: the part of taxonomy where if no one else has named it, you get to name it.
Since no two individual anythings are exactly the same, there are an infinite number of potential species.
Everytime they find something that makes us different from each other, there are countless other things discovered or hidden, that makes us all the same with "very few differences, but infinite variation."
Thank you for all the beautiful artwork and animation in this video! 😍
Plant speciation is really weird.
Like the dozen or so pistacia species in the Mediterranean and then theres one or two lone weirdo species native to north america that still seem to be both graft and cross compatible with the mediterranean cousins
Mandel was more right than Lamarck, but they were both kind of wrong, and we forget often that Mendelian genetics concern selection on traits directly. It wasn't monogenic expression, with single genes producing single traits, but rather traits were directly inherited. Only later were genes imagined to be specific kinds of physical objects. Most of the history of science is like this, with really progressive work also featuring profound incompletenesses or inaccuracy. Who we see as progressive but incomplete, and who we see as informative but discredited, is most often the product of later narration of past events. I think it's important to understand science as an incomplete process where few ever manage to be "right" in any final sense. Some fortunate and industrious few just manage to push our knowledge forward.
I believe the reason Mendel is still taught today is because learning Mendel makes learning the more up-to-date theories easier, and Mendel's work still makes some useful predictions. You see this a lot in science. Pre-quantum mechanics models of the atom are still taught in chemistry. Lewis structures are still pretty common in some areas of chemistry, and even when they were developed in 1916, they were a gross simplification rather than a rigorous model. They just happen to be a very useful gross simplification. I believe Mendel was aware that colour and texture of peas were unusually simple compared to most inherited traits, but that was why he chose them to work with. They allowed him to work out general principals using the technology he had available to him.
I don't see why this is controversial: the hummingbirds and pollinating insects are the environmental drivers of flower morphology, hence those individual plants from seeds with the full complement of genes for bird-favourable features will produce more offspring and out-compete those plants that half-arsed it by being intermediately favourable to either birbs or bugs; similarly those plants from seeds with the full complement of genes for pollinating insect-favourable features will also leave more offspring than those that failed to be fully favourable to bugs or birbs. This probably happens at a lower rate than when genes are shared due to being in proximity on chromosomes, but the benefits to reproduction in the individuals with the specialised genomes are probably great enough that inheriting the full complement of genes for either specialised phenotype offsets the lower rate at which physically distant genes are inherited together as a group. What would be interesting would be to conduct some experiments to see if any of the relevant genes move locus to become closer to each other over time, increasing the rate of production of individuals with the full complement of genes for highly specialised flowers.
The difficult or controversial part is how the different loci are linked eventhough they are not located on the same chromosome. So how can they be inherited together
I am glad you told us about the birds and the bees
Graduating with my undergraduate in bio rn and likely to do a plant genetics PhD. Will let u know if I figure it out.
This reminds me of the TNG line at the end of the episode with Troi’s star baby about how part of the beauty of scientific discovery is that we can’t discover everything.
I love how these videos have a way of making it understandable and relevant to our everyday lives. Thank you so very much. Scishow
Please correct me if this has already been discussed, but in response to this I would love to hear your presentation on the genetics of reptiles. Morphology in individual species is insane in the private hobby, and hybridization would be a great thing to discuss here. Anaconda species have produced viable offspring with redtail boas (boaconda). Baboon viper and Rhino viper (Gabino viper) hybrids are well known, and ball pythons have produced hybrids with Burmese pythons among a myriad of other species. Idk which hybrid offspring are viable for reproduction off hand, I'll do some research and add later, but it would be interesting to discuss the genetic factors that define species and what can reproduce with what in the different herp families
Got something already. Aspidoscelis neavesi is a hybrid species that ended up reproducing through parthenogenises, which seems to be fairly common in lizards and other odd occurrences in reptiles
Hank, Maybe plants have something like genetic barrier-carpool-lanes, so they have to travel together (due to something as yet undiscovered). I haven’t taught biology since 1993-4, so I’m darn rusty on some already outdated understanding. I’ll pass this on to my colleagues and students in case anyone’s feeling like a career in botanical genetics!
Perhaps it's a survivor bias issue. Hypothetically perhaps only the seeds that inherit those genes as a group are viable, therefore you'd only see plants that inherited those genes together.
Anyone else be reminded of Skyrim? The Red Blue and Purple mountain flowers..
One potential explanation is that while unlikely, for each gene in each of 21 loci, there are highly selected for genes that are codependent. In other words, you will never see plants without all 21 inherited as those offspring are not/are less viable.
Thanks so much for explaining these curious plants in such a pleasant and understandable manner!!❤
I mean miotoc drive breaks Mendel’s law of equal segregation so I could see a polygenic sort of miotic drive doing something similar during polen formation for those 21 variants. If indeed it’s simply strong selection the S value would be truly INSANE and higher than anything we see in animals.
4:09 I want to! I really really do want to do my PhD in genetics (plant or otherwise) but a lack of time and money get in the way of me going back to school 😭
A lot of universities have grad programs almost completely comped by the program for this sort of science if you are doing research and work as either a TA or research assistant, as well as additional fellowships and grants. That doesn't help the TIME part but may ease the financial part a little, if you were unaware.
@@omgmo1962that’s actually really good to know. Thank you.
In plant breeding we usually cause the formation of favourable haplotypes containing genes that aren't that close together.
Actually it's not uncommon to see linkage disequilibrium among markers in different chromosomes due to selection pressures, be them natural or not.
Source: seen it myself, PhD candidate in plant genetics
So much fun hearing Hank talk so voluminously about the birds and bees. 🐝
I believe what you’re describing is more a syngameon, not a species complex. A species complex is when two or more species are virtually indistinguishable, such as in the coral Fungia fungites.
No, a syngameon is defined as a group of organisms that hybridise frequently causing a lot of gene flow due to the weak reproductive barriers.
However, in this Penstemon spcies there are reproductive barriers caused by the differenr pollinators what makes hybrids very rare
Re: pronunciation of "loci" -- in Latin, the letter C is always a hard consonant; it was the Roman equivalent of the Greek letter Kappa. Also, the letter I was a long vowel, pronounced like "ee" is in English. Basically, the word should be pronounced like Tom Hiddleston's most popular character.
Tl;dr _loci_ is pronounced with a "k" sound
'LO-KEE is a valid pronunciation of loci, but so are 'LO-KAI and 'LO-SAI (all according to Meriam-Webster). 'LO-KEE would indeed be pronunciation in ancient Rome, but the pronunciation of Latin has changed a lot since then.
The Wiktionary article for loci references the article for foci, which states:
'Both the "hard C" and "soft C" pronunciations are accepted. Although focus has C followed by a non-frontal vowel and is thus universally pronounced with a "hard C", there is a grey area for pronouncing the plural form foci. Under normal orthography rules, the C should be transmuted due to it being followed by one of the three frontal vowels (e, i, and y), but the "hard C" pronunciation is also valid due to this word being the plural of a word that is strictly pronounced with a hard C.'
That is the correct pronunciatio restituta pronunciation. At the same time, most schools in Europe teach Latin in the medieval church Latin pronunciation, so (for example) the c in pronunciatio is not a k sound but a ch sound, and the t is a ts sound instead of a t sound, to an European student
Ultimately, both pronunciations (restituta and medieval) are considered valid
'Low-sigh' is correct according the traditional English pronunciation of Latin, which evolved just as naturally as every other regional Latin phonology. The fact that the English pronunciation has gone out of favour outside of scientific circles in the last 120 years doesn't make it wrong. You can no more say that any one Latin phonology is wrong than you can say that American phonologies of English are wrong. They're just different.
What a time to be alive
All it will take now is another insect pollinator to be discovered that simply loves the colour red and need a landing pad, or a tiny bat that is attracted to ultraviolet light and wants to hover and stick its tongue into a tubular flower.
so to use the bus analogy it is like a bunch of people getting off at the city centre. while technically chances should be equal, there is an outside incentive to get off *there,* an additional benefit that makes it more likely
I studied Molecular Genetics in the mid-80's [made lots of electrophoesis gels] when DNA identification was getting recognized as forensically viable. One of the basic actions of gene expression from DNA that I don't see mentioned much, is that the DNA is tightly coiled and specialized proteins/RNA will open up a section that is to be read. ie all of the DNA nor even a strand of a chromosome are ever fully opened and copied [except for regeneration - eggs & sperm - which is not for gene expression to make proteins]. DNA has several subfunctions, not just protein manufacture. It has sections that code for opening up sections to be replicated, opening code doesn't necessarily have an associated protein or RNA. It's basically the order to make something because . . . there's too much of something, too little of something, something needs regeneration, something needs to stop. Some cancers are because these coding areas forget to turn off. But what I am getting at is that most 'code', ie DNA segments, stay dormant until needed. Such as people are shorter when food is seasonally scarce - we get taller when food is abundant. And for most species we don't know what triggers the changes. [one that fascinates me is domestic pigs have sparse hair, but when they go feral, they get furry in one or two generations].
Hank, I discovered the mind blowing world of plant taxonomy recently. Here’s some things that deserve a video:
1. Kale, broccoli, cauliflower, brussel sprouts, cabbage, and kohlrabi are all the same species.
2. Citrus taxonomy is absolutely nuts - they hybridize very easily, and the ancestry of the lemon is complex criss-cross of mandarins, pomelos, and citrons.
3. “Tree” is not a taxonomic category - nor is “nut”, nor “berry”. These are forms that have resulted from the convergent evolution of vastly different plant lineages. An apple tree is more closely related to an almond tree, a blackberry bush, and a rose (Rosaceae) than a Brazil nut tree and a blueberry bush (Ericales) or an orange tree, a cashew tree, and poison ivy (Sapindales).
Finally, a grab bag of weirdly closely related plants: Spinach n’ Tumbleweeds (Chenopodiaceae). Eggplants n’ Tobacco (Solanales). Hops n’ Hemp (Cannabaceae). Bananas n’ Cardamom (Zingiberales). Cinnamon n’ Avocado (Lauraceae). And finally, Mapighiales (violets, flax, weeping willows, coca, ricin, cassava melons, and rubber).
Hummingbirds and bees are inadvertently doing selective breeding on beardtongues. Very cool.
I grew Penstemon of a number of cultivars for years and I never noticed who pollinated who. I love the image of the Anna's Hummingbird and the Bee great capture.
The word "species" is like the word "planet". It's a category that people invented. The universe doesn't have to always fit our categories, and just because if doesn't doesn't mean that the category is useless.
The word "loci" is the plural of "locus" (which comes from mathematics related to where things can be) and is pronounced LoKe-us with the hard sound in the middle. So loci is pronounced Loke-eye, not to be confused with Loki.
Both ways are correct. Low-sai is the English pronunciation and low-kai is the Latin pronunciation
You’ve been teaching me for a good part of my life. Thank you.
Just saying as an avid gardener and someone who works with plants, the hummingbirds here do not seem to care about color. They love all colors of penstemon, white, blue, red, or purple. In fact they’re favorite flower to visit in my experience actually seems to be black and blue salvia.
I wonder if there's some interesting selective pressures between dogs, wolves, and coyotes? All are capable of interbreeding with viable offspring, but are still counted as separate species for some reason. And generally there's a natural separation due to differences in behavior. So is there something similar going on with that group of mammals?
Where there's a theory there are exceptions. Also nice to see you
Particuarly Ecology. Ubiquitous with exceptions is a succint summary haha.
@@jdubelu540 these kind of vidoes are my favourite from scishoe
How is Mendel wrong? He never claimed anything to do with this, Mendel died in 1884, chromosomes weren't thought of until at least twenty years later. Apologize to poor Gregor.
He wasn't!!!
He was looking at discrete patterns of inheritance in pea plants before we even knew what a gene or even the chromosome was! But yet, he recognized there must have been some factors of inheritance (he called these unit factors). Gregor was awesome! But we know now genetics is complicated beyond our wildest dreams!
Yeah, this is more of a challenge to Thomas Hunt Morgan's discoveries about genetic linkage.
Shut up, nerd...
since when do dead men need apologies
Clickbait title, yo
My guess would be a methylation or some other structural "ID" (that could have epigenetic influence) would be at play, in which case they would likely have something in their centromere (centriole? Idk its been a few years since my degree, pls bear with me if this isnt the right term) structure which links and matches to these ID (probably protens?) during the division process to influence to which side of the cells the given genes are pulled
Its alternatively also giving me the impression of some antibody type functionality which would normally be associated with learned immunities hijacked into the reproductive process realm
........
I got into a phd program in 2020 and bailed last second at the thought of moving back to nyc at the start of the pandemic.....maybe i should reconsider the career trajectory im on now and go back to my eco-evo bio roots and reapply to new programs 😅
My brain is seriously, seriously running on this with so many mechanisms that would be possible to cause this
To me it just shows living beings have adaptation imprinted into their genes. In one situation, certain genes become dominant, in others, others do. It doesn't mean those characteristics necessarily disappeared. It means that they are temporarily suppressed but stay in the dna.
@scishow Would be great if you labeled your sources, or briefly describe what information you got from each link.
1:28 this bee interaction is fascinating 😂
When I was at uni 50 years ago we were taught that species is a shorthand not to get too hung up on.
Life is a continuum' it's just that lots of the intermediates aren't around any more.
That car vs bus analogy. Phenomenal.
There's a reason species separation methods are called methods, there is no one size fits all
The only unchanging principle in nature is that there are always exceptions to any rule we attempt to establish
Life is weird; as an increasingly decrepit pensioner, I find the SciShow videos fascinating, whilst back in the good ol' days of highschool, I found all science subjects as interesting as watching paint dry.
I'd wager a lot of that change comes down to a) how it's presented and b) being able to choose interesting topics and see how principles apply to it! I know I never would have learned about these flowers in my bio classes!
Plants hold so many answers to questions we can't even think to ask. I wonder how different microbial colonies in a plant's soil might impact its biology.
This means a humming bird may take the nectar of a flower for the bees. And a bee may take the pollen of a flower for hummingbirds on rare occasions. Explaining this phenomenon as the two different flowers can mix their pollens rarely.
The flowers: I want to start pollinating them using a soft paint brush, and you know , just messing around.
I remember studying Mendel in the 7th grade. It was fairly superficial and I feel now that perhaps my education was not what it could have been, but after all, it was 60 years ago.
Our definition of a species has needed work for a while. After all, by the current definition we’d be the same species as Neanderthals.
Yeah, or we accept that there is no perfect definition of a species just like there isn’t a good definition of a fish.
There are at least 26 different definitions of what a species is that scientists have come up with. None of the definitions are perfect, because definitions try to make the world orderly, but nature insists on being messy.
This is why flowers are hard in animal crossing
@1:31 Bee HighFive!
I‘m a fan of the illustrations in this one!
OK so as a genetics graduate, here's my potential theory that could be investigated
There could be interactions between the products of these genes that promotes the success of individuals which inherit them together, or perhaps interactions between the genes in hybrids that mean a large number of them aren't viable?
I thought Mendel's findings were more what you would call guidelines with our current knowledge
Huh, I wonder if you could artificially continue to breed hybrids would the 21 loci continue to divide as a group? That would test the theory if whether selection pressure is the only driving force or if there was something else?
Greetings from Mammoth Lakes! We get both pentstenom species here! The purple and mountain pride (pink). They from everywhere!
amazing - variations on top of variations even in the laws of nature!
I just love these studies so much!damn
Tentative hypothesis: there are control genes that maintain the blue version and the red version.
Doesn't explain white and off-white Penstemon, like eastern species P. digitalis, P. calycosus, both hummingbirds and bees pollinate both. Also, Chelone obliqua is pollinated by both hummingbirds and bees, and is white, sometimes with a light blush. These are all native eastern plants. Also, Mimmulus ringens, which is blue-purple and hummingbirds love. The real answer is not as simple as you think. There's more going on. We just haven't figured it out yet.
I think there is a master gene set at one locus that determines the final type by switching the rest of the genes on or off. But it also verifies it has a complete set of the necessary genes for its type and dies if it doesn't. Mutants have a version of the master genes that do not correctly check for every gene needed, and the mutant lives on but has a more difficult time passing on its mutant genes.
Yay! Finally my favorite local flowers got a cool entry! New Mexico is a land of secrets, BTW, but you ain't gonna unlock em without a local guide.
Okay. You convinced me. Life is likely to have occurred on other planets.
That was neat and all and it makes sense why hybrids aren't sustainable and don't reproduce together like bee flowers or bird flowers do.
But I'm not sure how this would make Mendel wrong in any way. I don't think he ever posited that all related traits have to be located near each other in the same chromosome. My understanding is that he was more observing how two independent traits tend to get passed down together if they are on the same chromosome.
I dunno. I might be missing something. But I kind of doubt the fact that a hybrid not necessarily being able to compete and thrive against regular flowers that are specialized to take advantage of a specific niche really breaks anyone's understanding of genetics.
Was the audio off for anyone else?
Sounds like the audio engineer really hit the de-esser hard.
We have a couple of the bluish varieties here in SD.
I don't quite understand the conundrum presented. The flower color and shape are connected to the flowers' pollinator. Crosses are essentially selected against because they don't attract either pollinator and the color/shape flowers are perpetuated. We find plenty of plant and pollinator symbiotic relationship in nature. In some cases, the two have become so dependent on one another that the extinction of one would lead to the extinction of the other. Selective pressures perpetuate the continued separation of these blue and red flowers of the same species because of the preferences of their respective pollinators. Over time, the genetics of these two varieties could diverge even more so they would be unable to reproduce together and hybridize - much the way horses and donkeys have.
@1:44 "Suck out the loads" is right there to be clipped. Can't wait for the ytp.