UNIVERSITY OF EXETER
A plant used in traditional Chinese medicine has evolved to become less visible to humans, new research shows.
Scientists found that Fritillaria delavayi plants, which live on rocky slopes of China’s Hengduan mountains, match their backgrounds most closely in areas where they are heavily harvested.
This suggests humans are “driving” evolution of this species into new colour forms because better-camouflaged plants have a higher chance of survival.
The study was carried out by the Kunming Institute of Botany (Chinese Academy of Sciences) and the University of Exeter.
“It’s remarkable to see how humans can have such a direct and dramatic impact on the colouration of wild organisms, not just on their survival but on their evolution itself,” said Professor Martin Stevens, of the Centre for Ecology and Conservation on Exeter’s Penryn Campus in Cornwall.
“Many plants seem to use camouflage to hide from herbivores that may eat them – but here we see camouflage evolving in response to human collectors.
“It’s possible that humans have driven evolution of defensive strategies in other plant species, but surprisingly little research has examined this.”
In the new study, the researchers measured how closely plants from different populations matched their mountain environment and how easy they were to collect, and spoke to local people to estimate how much harvesting took place in each location.
They found that the level of camouflage in the plants was correlated with harvesting levels.
In a computer experiment, more-camouflaged plants also took longer to be detected by people.
Fritillaria delavayi is a perennial herb that has leaves – varying in colour from grey to brown to green – at a young age, and produces a single flower per year after the fifth year.
The bulb of the fritillary species has been used in Chinese medicine for more than 2,000 years, and high prices in recent years have led to increased harvesting.
“Like other camouflaged plants we have studied, we thought the evolution of camouflage of this fritillary had been driven by herbivores, but we didn’t find such animals,” said Dr Yang Niu, of the Kunming Institute of Botany. “Then we realised humans could be the reason.”
Professor Hang Sun, of the Kunming Institute of Botany, added: “Commercial harvesting is a much stronger selection pressure than many pressures in nature. “The current biodiversity status on the earth is shaped by both nature and by ourselves.”
###
The research was funded by Chinese Academy of Sciences and National Natural Science Foundation of China.
The paper, published in the journal Current Biology, is entitled: “Commercial harvesting has driven the evolution of camouflage in an alpine plant.”
This is very, very interesting, not to detract from the finding. But, anyone who has tried to keep their lawn up knows that the dandelion species is way ahead with the disappear-from-humans selection scheme.
Or at least “grow shorter than the lawnmower blade”.
My rule for dandelions is “You bloom, you die.” It saved trying to find the unflowered plants and as they all eventually bloom, it’s quite thorough.
It’s called selection pressure and the plant is not evolving, but we are selecting those we can locate easily–we are culling the gene pool. They have lobsters around the British Isles, but they caught them so heavily that they caught any lobster that reached legal size. As a result, the remaining lobsters were slow growers and pretty much do not reach legal size much any more.
The key to New England lobster is that the shallow water population is mostly overflow from the deeper water genetic pool. So, we are not selecting from the gene pool, just overflow population. Years ago, they tried to lobster the deep waters, but it proved to be too expensive and labor intensive, thankfully.
Culling the gene pool is also a form of evolution.
Rabbits are fast because foxes are fast. Slow rabbits don’t survive.
Or you can also look at it from the other side. Foxes are fast because rabbits are fast, slow foxes don’t eat.
Very true. You can see teh same happening in elephant populations in Tanzania.
We were in the Selous National Park a few years back and saw a quite large herd of elephants with almost all of them having very small tusks.
As poachers prefer to take animals with larger tusks, those with the smallest are seen as less valuable (for the moment). It does mean that the large tusk gene is being removed from the gene pool and eventually elephants will either have small or possibly even no tusks. Sad but clearly happening.
Don’t over interpret observations such as this. Many genes likely help establish tusk size. Most mammals(including humans) phenotypes are governed by more than one gene. Human facial characteristics have many(10 or more??) genes. That explains why people display so many different faces, even from parents to children, much less multi generation changes.
When the large tusk “comes back into style” it will come back as quickly as it disappeared.
I’ve used a weed burner to dispatch weeds in my yard for about 3 years. I’ve recently noticed more weeds with small brown leaves (seriously). Did the weeds evolve to look like they’ve already been burned?? Nope, a quick review of weeds in my area showed that this brown weed was already here, it’s just that I was much more likely to kill the bright green and easily visible ones leaving more of the brown ones to survive and multiply. It’s clearly the case that these plants in China didn’t evolve. This story is more likely to be just another example of bad journalism.
The book is “Plagues and Peoples” by McNeill. He postulates that viruses don’t so much ‘mutate’ as fail to propagate. The deadlier strains kill the host before it can transmit to another host, but the milder strains can and so survive. The concept has been around for quite a while.
It’s an interesting read, including the part about the Black Death where Muslim countries at the east end of the Mediterranean did not impose a quarantine period on incoming vessels. “It is the Will of Allah, who lives, who dies.”
Back when West Nile Virus was a concern, it petered out before it reached the west coast of North America in quantity.
Theory was that only crows genetically resistant to the virus survived so transmission was low. (That might contrast with bats in Communist China who carry virus, but match research showing humans who do not feel significantly ill with the SARS-CoV-2 virus do not shed much of it.)
An interesting question in my mind was why so many of the ‘white phase’ of black bears live on Princess Royal Island on the BC coast, when they are move visible. Granted, there aren’t many human hunters around, I suppose cougars kill young bears. Then I read that fish can see black/grizzly bears, so some grizzlies have been fishing at night. So I theorize that the white phase bears do better at fishing than their black cousins.
(The white colour is a recessive gene, like red hair in humans, takes both parents carrying the gene for an offspring’s colour to appear.
This is how evolution works. Nothing surprising about it. Did IQ s drop sharply after I left Uni.?
Yes…
Not sure IQ changed but students deciding what they would like to be taught probably has a negative correlation with how much use their cripplingly expensive piece of paper is.
That sounds like a very unscientific measurement of the independent variable. I wonder how they estimate the error bars on that one.
Also, since there is no historical perspective, there may be other confounding variables which they have not investigated. Do humans have goats which also eat the plant ? What determines where humans live to start with and where they don’t? Are the same environmental factors also affecting the plants?
This is just more pseudo science which only gets published because it fits the narrative the humans are bad because they are affecting nature.
Clever plants. Very, very clever plants. Was it the Twilight Zone that had an episode something similar to this?
“This is how evolution works bla blah I was at university bla blah”
No, that is how the THEORY of evolution SUPPOSEDLY MAY work.
You obviously did not Universitise at the STEM level, where they know science has no answers, just increasingly pointed questions, and that theories are just tools with which to reach for better questions?
So, has your IQ dropped since you left university?
Evolution, like gravitation, is a fact, with a body of theory seeking to explain how it works.
So the plants that are now being observed most often in the harvested areas are those plants that weren’t before being observed as well in the harvested areas when the humans were harvesting them.
Well I’ll swanny . . .
“In a computer experiment, more-camouflaged plants also took longer to be detected by people.”
Really!? Is it just me or does anyone else think a computer or experiment is not needed to figure that out!
Oh come now G.
What . . . are you REALLY going to argue that there exists some OTHER pathway to Rome’s objective truth other than that which is paved via software model?
Pffft. You gotta get with the program there guy!
“In a computer experiment, more-camouflaged plants also took longer to be detected by people.”
Really!? Is it just me or does anyone else think a computer or experiment is not needed to figure that out!
I know! It’s Earth shattering stuff isn’t it?
I’ve said it before and I’ll say it again. I want to be a field researcher too!
Hmm … did they evolve to be less visible or are the ones that were less visible to begin with able to reproduce where the visible ones were harvested before they could reproduce?
I remember seeing something on TV years ago about dandelions. Those growing in a mowed lawn tended to have shorter stalks before flowering than those growing on the same property where the lawn mower couldn’t reach. (Around woodpiles, gardens etc. And this is the stalks before flowering.)
“or are the ones that were less visible to begin with able to reproduce where the visible ones were harvested before they could reproduce?”
That is evolution.
That’s the way Biston betularia changed their colour from white to black in England because of the indistial smut coloring birches from white to black and now the black Biston betularia where able to survive, that before had no chances on white birches.
In this case, it’s called indusrial melanism.
Same way, other reasons for the less visible plants, no mystery at all, but caused by humans.
Yes, but shouldn’t there be a distinction made between ‘survival of the fittest’ where nothing has mutated, just that the ‘weak’ were weeded out (so to speak), versus evolution because of a genetic mutation that changed or added something novel to the organism?
The conflation of those two, very different scenarios has always bothered me. If this is no longer the case, please forgive my ignorance. My last biology class was fifty-six years ago, and I just can’t keep up with all aspects of all science.
That an organism has a range of colors is the result of genetic mutation.
Any time an organism changes shape or color, it is because it’s genes have changed.
That is the simple definition of evolution. But such a simple definition is insufficient to support the concept of Evolution – that causes new orders, phylums, classes, families to come into existance.
Certain of the the variations in the color of the fur of cats, for example, is thought to be in response to variations in temperature of various body regions during gestation.
So it is not necessary to have genetic mutations to have different colors.
I change color over the course of a single season, and I am pretty sure I am not mutating back and forth.
Just sayin’.
Steve, not really.
Orders, phyllum, classes and so on are just lots of changes over a long period of time.
Many of these cases is NOT due to ANY mutations, no gene changes. The genes of multiple colors already exist, but one color becomes predominated or exclusive because the organisms having the other colors are made extinct. If we killed all white mice, eventually all mice would be black or grey. No genetic mutation required. It is a subtractive process, and should be called devolution.
+1 – and that’s EXACTLY what’s happening here. The word “evolution” and all of it’s conceptual domain, has gradually morphed to become synonymous with, or even replace the term “natural selection.” Many with whom I speak now don’t even use “natural selection” as a term of reference at all. Everything’s “evolution.”
It’s what happens when scientific categorical distinctions get lost in epistemological presuppositions. Or something like that.
SYCOM,
YES
A morph we’re all familiar with is CAGW into Climate Change with weather events being the “proof” that Man caused it.
Natural selection is how evolution works.
Thanks Mark.
Then it seems by the very language you’re using you agree with me that the two can’t be the same thing. They don’t conceptually equate with each other.
If natural selection is a *process by which* evolution works (i.e., “how” it works), then it must necessarily follow that natural selection can’t be evolution per se.
Natural selection is one evolutionary process of many.
It works on both existing genetic variation and new mutations.
New families, orders, classes and phyla emerge gradually, but new species and genera can arise in one or a few generations.
Natural selection is a result, not a process. Evolution is a process.
Repeating myself yet again, natural selection is a process, the result of which is evolution, ie change in the heritable traits characteristic of a population over generations. Similarly, breeding, aka directed evolution, aka artificial selection, is also a process, achieving the result of acquiring trait desired by the breeder in a line of organisms, eg shorter legs and more wool in domesticated sheep.
“That is evolution.”
Not necessarily. Did they go back the next year before the harvest to see the color distribution? It may just be that the easy to spot plants were gone when they went to the fields. It doesn’t say anything about whether the hard to spot plants had hard to spot offspring. Natural selection only matters until the subject has offspring.
“Hmm … did they evolve to be less visible or are the ones that were less visible to begin with able to reproduce where the visible ones were harvested before they could reproduce?”
Yes.
Melanisn isn’t evolution, because we can suggest both variants coexist.
An increase in the population of one genetic variant and decrease in another from one generation to the next is evolution.
Unter certain conditions it may be a step to evolution. As both variants coexist and will continue to coexist in other places not further researched we can’t talk about evolution as long as one variant doesn’t extinct but is only hidden for longer or shorter times.
Nope.
Evolution in one local population is still evolution. Many new species arise in just this way, after generations of reproductive isolation produce two species where before there was only one. Natural selection isn’t even required, just stochastic processes.
Evolution is the change in gene and allele frequency from one generation to the next.
I should add change in a population. If one population of an organism is changing, but another isn’t, or is changing in a different direction, it’s still evolution, in both populations.
Consider ring species, such as zebras, in which each geographic subspecies is interfertile with its neighbors, but the two ends of the chain aren’t. Language dialects often work the same way.
Evolutionary processes of course also work to keep vital metabolic functions intact.
Classic example of ring species are Arctic gulls in Genus Larus:
https://en.wikipedia.org/wiki/Ring_species#:~:text=The%20classic%20ring%20species%20is,represents%20an%20actual%20ring%20species.
You can’t compare f.e. zebras with these platns in question.
The strongest stripes on zebras you find in the tsetse belt, developed during the equus migration from NE to south, in the tsetse region you have only strong striped zebras.
The questioned plants coexist as the moth of the birches in at least 2 differnt colors simulaniusly in the same region. In dependance of the circumstances, or the one or the other has advanteges in reproduction, there is no further genetic change /shift from one to the other generation. It shows only the variability of these coexisting plants.
The moths too existed and exist in both variations, the black and the white.
The evolutionary step happend before, producing several variants or the respective ability to produce both variabilities.
What wasn’t researched was in how far the one or the other form of plant has more dominance than the other, the genetich research is still missing for better comparing both variants, as we have no clue if we discuss about hybrids.
Krishna,
Evolution in these plants is like adaptation in Darwin’s finches and the pepper moths.
It doesn’t matter whether the color variation existed before human predation or not. Evolution is change in frequency of heritable traits. If before humans began picking them, green was more common than gray, but now gray is more common, that’s still evolution.
It would still be evolution if the gray-producing sequences or allele was an innovation.
I don’t know why this is hard to get across, but I suspect creationist lies have muddied the waters for some.
So the variations that were harder to see, got to live and to reproduce..
How is this in any way “remarkable ” ???
The remarkable part is that they were able to trace it to human harvesting. Most of the time it’s driven by herbivores.
I’m amazed it wasn’t blamed on climate change.
Just wait for the follow up “studies”.
That’s in no way remarkable. This whole story is unremarkable. In fact it’s even less remarkable BECAUSE it’s human driven.
Amazing that the “researchers” re-discoverd agriculture 😀
And believe they have to publish a paper about.
Wow, that Darwin. Now for the Transparent Rhinoceros…
Survival with enough descendants to continue the species explains all life.
“We thought that this evolution was being driven by herbivores, but we didn’t find any….”
This university does not appear to realise that, as omnivores, humans consume plants in just the same way as cows do. This environmental exceptionalism which requires humans to have NO impact on any other life-form on the planet is going too far…
That’s what I thought DG…. and also…
“Many plants seem to use camouflage to hide from herbivores that may eat them – but here we see camouflage evolving in response to human collectors.”
….. I imagine, for the aforementioned Fritillaria delavayi plants, the difference between getting eaten by a goat or harvested by a china person is neither here nor there.
The Professeur finishes with a “no sh@t Sherlock” scientific bombshell…
“The current biodiversity status on the earth is shaped by both nature and by ourselves.”
“The current biodiversity status on the earth is shaped by both nature and by ourselves.”
Almost correct.
The current biodiversity status on the earth is shaped by nature.
Our existence is natural. We ourselves are part of nature not apart from nature.
The highest biodiverity beside rainforests you have in greater cities, f.e. Munich or Berlin, where millions of people live.
Biologist Josef Reichholf discusses the benefits of a warmer climate for animals and plants, large cities as centers of biological diversity and the myth of the return of malaria.
I am not so sure that evolution is what is occurring.
It seems to me that what others have already noted is occurring.
There are some plants that are more difficult to see, and those ones are of course more readily overlooked by people picking the slopes clean of them.
So the ones left over will be the ones that are harder to spot, and will tend to give rise to offspring that are similarly hard to see.
If I go outside and chop down all my red hibiscus bushes, and then next year notice that the hibiscus left on my property have changed from mostly red to 100% not red, have they “evolved”?
“So the ones left over will be the ones that are harder to spot, and will tend to give rise to offspring that are similarly hard to see.”
That is evolution.
Mendel’s Law.
I do not think it meets to criteria of evolution, strictly speaking.
Any more than selecting certain dogs or cats to be allowed to reproduce is evolution, or selecting certain wheat plants to grow the next crop is evolution.
If breeding is evolution, then yes, it is evolution.
Basically people are hand selecting out certain ones and leaving others.
Breeding is evolution. It;s directed evolution, but it is still evolution.
People that spend a lot of time thinking about this stuff disagree with each other on this type of thing.
This particular example involves only removal of certain individuals.
There is no indication that such selection will accrue over time.
SJ Gould touched on this with his theory of punctuated equilibrium:
“Evidence for stasis has also been corroborated from the genetics of sibling species, species which are morphologically indistinguishable, but whose proteins have diverged sufficiently to suggest they have been separated for millions of years. Fossil evidence of reproductively isolated extant species of sympatric Olive Shells (Amalda sp.) also confirm morphological stasis in multiple lineages over three million years.
According to Gould, “stasis may emerge as the theory’s most important contribution to evolutionary science.” Philosopher Kim Sterelny in clarifying the meaning of stasis adds, “In claiming that species typically undergo no further evolutionary change once speciation is complete, they are not claiming that there is no change at all between one generation and the next. Lineages do change. But the change between generations does not accumulate. Instead, over time, the species wobbles about its phenotypic mean. Jonathan Weiner’s The Beak of the Finch describes this very process.””
https://en.wikipedia.org/wiki/Punctuated_equilibrium
Developing a new breed of dog is accomplished by culling out particular genetic traits from an isolated population until only the desired traits remain. “Pure bred” means the genes for all unwanted traits have been eliminated. No new genetic coding has been added. That is the opposite of Evolution. A worm species could not evolve eyes, for example, by losing codes.
Evolution requires introducing new codes into the genetic makeup if simple creatures are to gain features that never existed before.
Evolutionary theory proposes genetic codes change by one accidental mutation at a time. If a mutation produces a change that results in more offspring, that mutation spreads through the population. If no increase in offspring results, that particular mutation is not selected, and fades out of the gene pool.
Vision cannot evolve gradually one mutation at a time. Nor can appendages, fins, hearts…anything. Each new trait would require a multitude of simultaneous code changes, both for the body site, and for the brain. The first code change, for a new feature, that came to be would be lost before the 2nd came along.
Every DNA mutation that has been claimed to be “Evolution” has actually been a change to the code for a single protein, that caused a color change or the loss of a function.
The selection of one preexisting variant of a physical feature, over another, is not “Evolution”. Nor can the Theory explain how that feature got there in the 1st place.
Evolution is change in allele frequency in a population from one generation to the next.
Sometimes new genetic material is involved, but not necessarily. New sequences arise all the time by various means.
Vision has evolved repeatedly.
John, you are claiming selection of one pre-existing variant over another is responsible for introducing completely new features.
Claiming that has happened does not address issues with your claim that have been raised by multiple posters.
Steve,
No, I’m not.
Again, evolution is change in gene or allele frequency from one generation to the next. It doesn’t matter whether the change has arisen because of new mutations or other sources of variation, or was pre-existing.
I did not say that change in allele frequency causes new genetic sequences. Again, I said what is the case, ie that evolutionary processes such as selection work on both old and new genetic sequences.
This is really elementary stuff. If some commenters don’t think it works like this, they should study evolution 101.
John, this thread has a difference of definition driving the difference of opinion on whether the fritillaria study in the article demonstrated evolution or not.
You are defining any change in allele frequency in a population as evolution. (The standard definition)
Others, like me, are saying that because a change in the frequency of variants in a population does not create viable new genetic sequences, no real evolution occured in the fritilaria example. Without new genetic sequences that yield new physical traits, no change in taxa above the genus level would ever occur. Since the Evolution Theory requires evolution of higher taxa, mere changes in allele frequency should not be called evolution.
Steve,
You don’t understand what evolution means. It occurs all the time, not just when higher taxa evolve.
It happens within populations of a species, at the formation of new species, genera, families, orders, classes, phyla and kingdoms.
Adaptation is an evolutionary process. Speciation is another.
Biologists define evolution as change in the genome of a population from generation to generation. The change doesn’t have to produce a new species or higher taxon.
Please quit falling for creationist lies and study science.
One of the axioms of the “Save the Planet Crowd” is that whatever Man does is not “Natural”.
If they admit that Man is part of “Nature” and what he does is “Natural” then what excuse would they have to control Man to protect “Nature”?
They like to give “Nature” a higher priority than Humans.
Great point.
Even better: Since “evolution” is all about lizards turning into monkeys turning into humans, the question for the hibiscus changes is: Did your remaining hibiscus become cherry trees?
And for the frittilaria: So now they’re a different color frittilaria–is that “evolving?” Doesn’t “evolution” postulate that the frittilaria should become lichens, or grow legs and start walking, or “adapt” into mung bean plants?
Staying a frittilaria, but a different color frittilaria sure seems like pretty weak tea for evidence of “evolving.”
Since your initial point is utter nonsense, every conclusion derived from that point is a waste of time.
The basic point he was making is correct.
Fish evolved from less advanced forms, and the process of moving onto land involved an evolution to amphibian forms, which at some point in time had some lineages developing eggs that did not need to be laid in water.
Also as this sequence occurred, the heart evolved from the two chambered heart seen in fish, to the three chambered heart of amphibians, and then the four chambered heart of reptilians.
And so fish had evolved into reptiles.
Obviously the evolutionary steps along the way did not involve any modern species…they occurred within the lineages which were in existence at the time the process was occurring.
Reptiles evolved into mammals with the intermediate lineages known as therapsids, which over time came to resemble mammals.
And one lineage of mammals became the first primates.
The last common ancestor of modern monkeys and of humans was not a human or a species of monkey that is now extant, but if we were to see one walking down the street, I think most people would recognize it is distinctly monkey-like.
Someone who has not studied much in the way of zoology may be unaware of the distinction between monkeys and apes, let alone the great apes, or even to be able to distinguish the old world monkeys from the new world monkeys, but aside from these particulars, if one was to generalize reptilians as “lizards”, and higher primates as “monkeys”, then what Kent said is essentially correct.
Current evolutionary theory holds that all living species can trace their lineages to a common ancestor at some point in the dim distant past, and so logically the sequence he described does comport with what evolutionary biologists believe to have occurred over time.
But this example of the plants is different.
There was no evidence presented that any change occurred in the plants that are there now.
Just that some individuals were removed by a process that is akin to culling by hand selection of certain colors of the species.
If someone wants to call that evolution, then so be it.
I have never heard it called that when, for example, corn with larger ears are developed.
That corn did not evolve, it was bred.
People are distinctly larger on average now than was the case 100 years ago.
Have we evolved to be bigger?
I think the change is most likely epigenetic.
If we are all starving through every Winter for a couple of generations, I think on average we will get smaller again, with no underlying change in our genetic sequences.
Girls in the US back in the 1960s had menarche at around age 13, although 12 or 14 was not unusual. Having it happen at age 8 was unheard of, as far as I know, and yet in 2020 it seems to be not even particularly surprising, although it is still unusual.
https://forums.webmd.com/3/parenting-elementary-ages-exchange/forum/451
(Over the past 1500 years, the average age of first menstruation has been as old at 16 or 17, and the current average of about 12 And that is just the average.)
A girl in Peru is documented to have given birth when she was somewhere between the ages of 5 1/2 and 6 1/2!
Again, epigenetics, not evolution.
Still, if the technical definition of evolution includes something like this, then so be it.
I would not consider it to be, though.
Fifty years ago, the most common breeds of dogs were German Shepards and Golden Retrievers, at least that is what I most saw in Philly back then.
Nowadays, various breeds known colloquially as “pit bulls” seem to be by far the most common.
Does that count?
BYW…I did not mean to imply that I think the cases of precocious puberty that led to a girl giving birth at age ~6 is an example of epigenetics.
Just the varying age of menarche that is documented to have taken place over the centuries and into the present.
Interestingly, these changes appear to correspond to periods of warmer and colder climate regimes, with the oldest average age of puberty coming during the harsh period we refer to as the Little Ice Age.
Apparently there was a rapid change between the early 1800’s and the end of the Victorian era. It may have been even more dramatic than that which occurred over the past 50 years or so.
Here is a reference to what I was describing just above:
https://www.bustle.com/articles/114490-the-average-age-women-got-their-first-period-throughout-history
Not exactly a research paper, but it seems to be well referenced.
”That corn did not evolve, it was bred.”
Life forms change due to external influences. Whether it is forced by natural systems of humans makes no difference. Call it different names if you like but it’s the same thing.
Technically, mammals did not evolve from reptiles. Both reptiles and mammals evolved from anapsid amniotes. Reptiles are diapsids and mammals synapsids.
Anapsids lack holes in their heads behind the eye socket. Diapsid skulls have two such post orbital fenestrae and synapsids one. Turtles look anapsid but their lack of holes is secondarily acquired. Their ancestors were diapsid.
Age at menarche isn’t evolution unless change in it is derived from genetic variation from one generation to another in a population. If from better nutrition, it’s not evolution.
“Both reptiles and mammals evolved from anapsid amniotes. Reptiles are diapsids and mammals synapsids.”
I am wondering whose system of classification you are referring to here?
Certainly there is plenty of room for disagreement, and things are getting very confusing with attempts to retain old systems of classification while also switching over to new ones.
Typically though, anapsids were one of the four clades of reptilians.
And only most reptiles were considered diapsids.
Turtles have mostly been considered to be anapsids, and most people call them reptiles.
Therapsids were reptiles, in almost every classification I have ever seen.
I spoke in the most general terms because there is little or no consensus when it comes to taxonomy for the past 30-40 years, and there have been many disagreements as long as people have been making such classifications.
Recently, the system called phylogenetic classification seem to have taken the upper hand.
But anapsids and therapsids have traditionally been called reptilians:
“In the late 19th century, a number of definitions of Reptilia were offered. The traits listed by Lydekker in 1896, for example, include a single occipital condyle, a jaw joint formed by the quadrate and articular bones, and certain characteristics of the vertebrae. The animals singled out by these formulations, the amniotes other than the mammals and the birds, are still those considered reptiles today.
The first reptiles had an anapsid type of skull roof, as seen in the Permian genus Captorhinus
The synapsid/sauropsid division supplemented another approach, one that split the reptiles into four subclasses based on the number and position of temporal fenestrae, openings in the sides of the skull behind the eyes. This classification was initiated by Henry Fairfield Osborn and elaborated and made popular by Romer’s classic Vertebrate Paleontology. Those four subclasses were:
Anapsida – no fenestrae – cotylosaurs and Chelonia (turtles and relatives)
Synapsida – one low fenestra – pelycosaurs and therapsids (the ‘mammal-like reptiles’)
Euryapsida – one high fenestra (above the postorbital and squamosal) – protorosaurs (small, early lizard-like reptiles) and the marine sauropterygians and ichthyosaurs, the latter called Parapsida in Osborn’s work.
Diapsida – two fenestrae – most reptiles, including lizards, snakes, crocodilians, dinosaurs and pterosaurs.”
“By the early 21st century, vertebrate paleontologists were beginning to adopt phylogenetic taxonomy, in which all groups are defined in such a way as to be monophyletic; that is, groups which include all descendants of a particular ancestor. The reptiles as historically defined are paraphyletic, since they exclude both birds and mammals. These respectively evolved from dinosaurs and from early therapsids, which were both traditionally called reptiles. Birds are more closely related to crocodilians than the latter are to the rest of extant reptiles. Colin Tudge wrote:
Mammals are a clade, and therefore the cladists are happy to acknowledge the traditional taxon Mammalia; and birds, too, are a clade, universally ascribed to the formal taxon Aves. Mammalia and Aves are, in fact, subclades within the grand clade of the Amniota. But the traditional class Reptilia is not a clade. It is just a section of the clade Amniota: the section that is left after the Mammalia and Aves have been hived off. It cannot be defined by synapomorphies, as is the proper way. Instead, it is defined by a combination of the features it has and the features it lacks: reptiles are the amniotes that lack fur or feathers. At best, the cladists suggest, we could say that the traditional Reptilia are ‘non-avian, non-mammalian amniotes’.
Despite the early proposals for replacing the paraphyletic Reptilia with a monophyletic Sauropsida, which includes birds, that term was never adopted widely or, when it was, was not applied consistently.
Bearded dragon (pogona) skeleton on display at the Museum of Osteology
When Sauropsida was used, it often had the same content or even the same definition as Reptilia. In 1988, Jacques Gauthier proposed a cladistic definition of Reptilia as a monophyletic node-based crown group containing turtles, lizards and snakes, crocodilians, and birds, their common ancestor and all its descendants. While Gauthier’s definition was close to the modern consensus, nonetheless, it became considered inadequate because the actual relationship of turtles to other reptiles was not yet well understood at this time. Major revisions since have included the reassignment of synapsids as non-reptiles, and classification of turtles as diapsids.
A variety of other definitions were proposed by other scientists in the years following Gauthier’s paper. The first such new definition, which attempted to adhere to the standards of the PhyloCode, was published by Modesto and Anderson in 2004. Modesto and Anderson reviewed the many previous definitions and proposed a modified definition, which they intended to retain most traditional content of the group while keeping it stable and monophyletic. They defined Reptilia as all amniotes closer to Lacerta agilis and Crocodylus niloticus than to Homo sapiens. This stem-based definition is equivalent to the more common definition of Sauropsida, which Modesto and Anderson synonymized with Reptilia, since the latter is better known and more frequently used. Unlike most previous definitions of Reptilia, however, Modesto and Anderson’s definition includes birds, as they are within the clade that includes both lizards and crocodiles.”
So if anyone wants to declare one of these various and contradictory points of view within the field the correct one, of course that is a choice one can make, but expect to find those who disagree.
In any case, none of that had anything to do with the point I was making.
And I did keep it general, and also was careful to point out that things that occurred in the past occurred within lineages and clades that existed in the past.
The evolution of the four chambered heart is one thing I have not seen any major disputes about.
I do not know what you mean by
“Technically” in your first sentence.
Mammalians have certainly always been considered to have evolved in several stages from reptilian ancestors.
Some may have other opinions, but opinions are not technicalities, and none of this is factual…it is all strictly theoretical and descriptive.
Personally, I would rather spend my time talking about the gaping holes in evolutionary theory that have been known for decades, and are getting worse, not better, the more that is learned.
Some of the problems are mathematical: There is simply not enough time elapsed at certain intervals for random mutations to explain emergence of new lineages, structures, and body plans:
https://youtu.be/noj4phMT9OE
Some of them are chemistry-based, and regard how it could have ever been possible for inanimate material to become alive:
https://youtu.be/zU7Lww-sBPg
And some seem to be logical paradoxes: New body plans represent new information.
Random chance can never change a random stew of genetic letters into the Encyclopedia of Life:
https://youtu.be/2A60UP3FIdU
Nicholas,
I’m using standard cladistic phylogeny, based upon natural groups through shared derived traits, hence descent from common ancestors. Linnaean classification is still used to name some of the clades, but that system can’t accomodate all relationships.
Reptilia is now technically called Sauropsida (“lizard faces”), a taxonomic clade consisting of reptiles (including birds) and the extinct Parareptilia. The term originated in 1864 with Thomas Henry Huxley, who grouped birds with reptiles based on fossil evidence. Sauropsids are the sister taxon to synapsids, some of which later evolved into mammals. Synapsid ancestors of mammals used to be called “mammal-like reptiles”, although synapsids don’t belong to Class Reptilia.
Amniotes include both Sauropsida, ancestral to lepidosaurs, ie squamates (lizards and snakes) and tuataras, and the archosaurs, ie crocodilians and birds, and Synapsids, ancestral to mammals. Turtles appear based upon their genomes to lie closer to archosaurs than to lepidosaurs.
Yes, the arrangement of fenestrae on extinct marine “reptiles” varied, but mosasurs were lepidosaurs. They evolved very rapidly from land lizards.
New genetic information happens all the time, as it can’t help but do. Sometimes a passing cosmic ray can create a new species via a single base deletion, as has happened with nylon-eating bacteria, formerly sugar-eating.
Supposed “gaping holes” in evolutionary theory are simply packs of lies by paid creationist liars.
Like all scientific theories, the fact of evolution has areas of disagreement, But that evolution occurs, ie new species arising from old and genetic change within species, is simply a fact, observed every day in every way, all the time, everywhere.
You are right. It would only be evidence of evolution if it could be proved that the less visible varieties never existed before.
Even then, it would stil be a very mild type of evolution. Robust evolution creates new families, classes, phylums.
Evolution occurs regardless of whether the genetic variation involved is old or new.
Profound transitions have occurred without new mutations, but just more or less of a heritable trait already extant in the evolving population. Lobe-finned fish evolved into tetrapods in part simply by their fin rods becoming more calcified, en route to becoming finger bones. Those fish better able to do push-ups to gulp air had a great selective advantage in their anoxic environments. They already had lungs as well as gills, like their and our modern lungfish kin.
Similarly, many of the traits characteristic of mammals evolved without genetic innovations, where “genes” means protein coding sequences.
Much as the cartilagenous rods of lobe-finned fish evolved into finger bones by increasing their calcium content, mammalian hair relies on the same keratin (protein) genes as “reptilian” scales and their modification into avian dinosaur feathers.
Mammalian evolution is fascinating, as are all the Linnaean class- and order-level transitions. Fur and lactation evolved in the synapsid ancestors of mammals even before the cladistic “Mammaliformes” level of development.
As usual, it’s fairly arbitrary where you decide to separate mammals from protomammals. For me, it’s whether the clade has the mammalian jaw joint, unique among jawed vertebrates. Others consider forms such as Morganucodon, which have the mammalian joint but also the “reptilian” joint, to be proto-mammals. But even in these Triassic genera, the old, reptilian joint has already been adapted to enhance hearing, en route to the three former rear jaw bones of other vertebrates becoming the unique mammalian middle ear bones, ie hammer, stirrup and anvil.
In short, the transition to Linnaean Class Mammalia required no genetic innovations, where genetic means protein coding sequences. It required simply repurposing keratin genes for fur rather than scales, then apocrine secretions for milk, and the three small bones at the rear of other vertebrate jaws for hearing, with the new joint involving the dentary bone, ie that with teeth.
Voila! Mammals.
John, how can you say repurposing keratin genes for fur rather than scales required no genetic innovation because the keratin protein is the same? The genetic coding that directs the construction details of the particular body parts is what distinguishes creatures from one another. Chemical makeup varies very little. (Its why we can eat
most things.)
Steve,
Easy, because it’s true.
Genes code for protein. There are different forms of keratin, but the main difference among keratin-based integuments has to do with epigenetic DNA sequences controlling how the keratinous structures develop.
It’s similar to but more complex than the differences in epigenetic control of hair growth between humans and our great ape kin. We have the same number of follicles per square inch as do chimps. But our body hair grows shorter than theirs.
Dinosaur scales evolved into feathers under epigenetic control without the evolution of a new protein-coding gene.
Something similar happened in the evolution of pterosaur pycnofibers. It’s even possible that the common ancestor of dinos and pteros had some kind of proto-feather integument on at least parts of its body.
We know what dino scales looked like, which is a bit different from crocodilians. But both groups share the beta keratin gene.
Consider the diversity of keratin structures in mammals: hair, horns, claws, nails, etc. All made from the same protein, yet formed into different shapes under epigenetic control sequences. Protein-coding sequences, ie genes, make up only a small part of a genome.
Humans have around 19,000 of them, a total subject to further revision, probably downward, as has been the trend.
Failed to mention hooves in the H-series.
Evolution or progression? Less viable? Only one choice: abort it, NOW.
Evolution, because if humans or herbivores stop harvesting, the more visible will grow again in quantity.
If the genes offer several variabilities, the better adapted for survivng have the advantage.
Hmmm . . . plants can learn to adapt to predation—especially from humans, if the above report is to be believed—but for some strange reason have no ability whatsoever to adapt to man-made climate change™.
Go figure.
That’s right to the point, Gordon, congratulations.
GAD,
The plants didn’t learn doodlysquat. Rather, the population contained enough genetic diversity to allow some members to survive this particular selective force.
Precisely.
The plant hasn’t changed at all.
It existed in several colours,
…. it just so happens that the less visible version suits this environment better.
Its like if a person liked white petaled daffodils and planted only that sort in their garden, and removed any yellow petaled ones that grew.
Would you say the white petaled daffodil “evolved” or “adapted” to suit that garden ?
”doodlysquat.”
Nice word. I’ve always referred to the more common diddlysquat but I think I like yours better 🙂
“All behavior has heritable components. All behavior is the joint product of heredity and environment, but differences in behavior can be apportioned between hereditary and environment.”—source: Cognitive Neuroscience: Notes for Wine Lecture, GENES AND BEHAVIOR, ÓJ. J. Wine, 2000 via https://web.stanford.edu/~wine/202/g-and-b.html
So, WRMAC, perhaps your view of “learning” is a bit too restricted?
Well, the plants themselves learned nothing. A human body learns nothing through evolution.
However, the plants’ and human gene pools learned. The way survival of the fittest works is to be unfit for survival (long enough to reproduce or otherwise benefit the gene pool) and thus exit the gene pool.
Each gene in a gene pool is a replicator. If it doesn’t replicate it loses the title “replicator” having failed to do so.
The seedless grape gene pool (having been castrated) finds itself in an environment where that gene pool flourishes. Humans are part of the natural environment for other gene pools.
Old.George posted: “Each gene in a gene pool is a replicator.”
Well, not so in reality. Many observations and experimental studies have show the genetic replication is easily (and often) modified by a particular organism’s exposure to environmental chemicals and environmental radiation. It is most valid to say that each gene in a gene pool is a POTENTIAL gene pool modifier.
A true replicator would not permit “spontaneous” genetic variations to occur, absent sex-originated genetic recombination.
Moreover, there is this: “Positive experiences, such as exposure to rich learning opportunities, and negative influences, such as malnutrition or environmental toxins, can change the chemistry that encodes genes in brain cells — a change that can be temporary or permanent. This process is called epigenetic modification.”—source: https://developingchild.harvard.edu/science/deep-dives/gene-environment-interaction/#:~:text=Positive%20experiences%2C%20such%20as%20exposure,process%20is%20called%20epigenetic%20modification.
Whether or not such epigenetic modification occurs in plants (as compared to animals having distinct brain organs) is debatable, to the best of my knowledge.
Silly Gordon, NOTHING can adapt to Climate Change! The only solution for Climate Change is the destruction of capitalism and Western civilization. (That’s what it’s for).
Isn’t this what used to be known as adaptation?
Captain Obvious reports survival of the fittest to survive in the environment. In other news foxes eat the slow rabbits.
My god, that can’t be right! My bazillion dollar computer model indicates that slow rabbits eat foxes.
(In other computer model news, increasing CO2 causes warming).
A hundred years ago in school we were taught that moths in the industrial areas of Britain became darker in a fairly short time after genuine carbon pollution started to settle in the woods. Or at least the proportion of darker moths in the population increased
Biston betularia, as mentioned above
It was a common grade school textbook example, when I was a lad.
Similarly, human rights activists who are most visible are most likely to be “harvested”.
just like climate change, they will try to see evolution everywhere.
Evolution does occur everywhere, in every generation of living things.
Man-made climate change also happens on local and regional scales. Globally significantly, not so much.
I am not sure you can call this “evolution” – it’s more just selection.
To “evolve” you need mutations…selection works on what is already present. So people are selecting the plants they can see easier and leaving the less easily seen ones behind – this suggests that the adaptation was already there in the population and it’s just now being passed on more.
Evolution requires selection, but selection does not require evolution, just a range of available traits. Traits often show up as some form of a normal curve and outside pressures then deform it into a another shape – maybe with multiple peaks or maybe just a slewed normal curve of some sort.
It would not surprise me if this same plant had multiple affected traits…one for color and one for growing lower to the ground for example.
I agree. There is no “evolution” here if a plant has multiple variants and some of the variants suffer from excessive harvesting, even if said variants are totally eliminated. (Light varieties of biston betuleria persisted, and dark varieties were present before industrialization.)
True evolution (what gets argued about) requires new physical structures to come into existance that transforms a species into a new family.
Some of Darwin’s examples of natural selection involved changes in morphology that did not necessarily involve new structures, per se.
A notable example is the beaks of various birds, in response to their preferred food source, IIRC.
Yes. I don’t know where people get the idea that evolution only occurs when new mutations arise.
A classic example from artificial selection is corn (maize) v. its wild ancestor teosinte grass. They look little alike, but are genetically practically identical. The differences arise from epigenetic changes in control sequences, not in genes, ie protein-coding sequences.
Selection works on genetic variation in a population, regardless of whether the diversity previously existed or was newly acquired. Selection is but one evolutionary process.
Evolutionary processes fall into two general categories, ie 1) directional, eg natural and sexual selection, and 2) stochastic, such as genetic drift, the founder’s principle and reproductive isolation.
Behind all processes is genetic variation in reproducing populations, which can arise from many sources, to include mutagenic agents such as cosmic rays, viral or microbial infections (horizontal gene transfer) and duplication, deletion or substitution of genetic sequences during mitosis or meiosis. To name but a few such sources.
I wish Michael Mann, Naomi Oreskes, and some others would evolve in a similar fashion.
So the more obvious plants are noticed and picked by humans. The ones that are harder to spot are not. Their descendants look like them. Natural selection at work – but obviously caused by CO2 somehow.
CO2 and Donald Trump refusing to wear a mask!
Obviously. That is how Science works these days, right?
(sigh)
Article uses “evolves” when it’s actually a case of unintelligent design (natural selection).
Yes it’s not ”evolution” but it’s the start of the process. You can’t separate the two. There’s no such a thing as a static life form. Sometimes it’s fast and sometimes it’s slow.
“There’s no such a thing as a static life form. “>/em>
Yes there is..
The mind of an AGW “believer”
“There’s no such a thing as a static life form.”
Numerous species have existed unchanged for millions, tens of million, hundreds of millions, and even billions of years.
While many might instantly think of cockroaches, in fact numerous species have existed in an unchanged for vast stretches of time.
Horseshoe crabs, hundreds of millions of years.
A brachiopod called Lingula has existed unchanged for over 500 million years.
And Stromatolites have existed unchanged for some three billion years.
Ctenophores: 700 million years.
Coelacanths: 80 million years.
Elephant sharks: 420 million years
Crocodiles: 58 million years
Fig Wasp: 34 million years
Ginkgo Biloba: 200 million years
Cycads: 230 million years
Pacific Palau Cave Eel: Uncertain…the living ones appear to be more ancient that the oldest known fossils. Hundreds of millions of year.
Nautilus: 500 million years.
It may be impossible to prove in some cases that these are indeed the same species for all that time, but the evidence indicates that are the same.
No one has demonstrated they are not.
The fossil record does not show gradual changes from one form to another.
It shows long periods where mostly things stayed the same for long periods, and short intervals where new things suddenly emerged, and for which no intermediates are seen.
Hence the paradox that leads to new ideas like Punctuated Equilibrium.
Gradual changes accumulating over time are not what is mostly seen in the fossil record.
Yes, the fossil record is spotty, preservation is a rare event, and geologic time is vast.
Detailed scientific knowledge is the starting point for the most significant paradoxes, they are not arguments from ignorance.
The fossil record shows both rapid and gradual change. Human evolution provides ample instances of both.
Punctuated equilibrium is Marxist claptrap. It was recognized as such when the scheme was first hatched, but improvements in the fossil record have given it the kibosh.
Natural selection is one of many evolutionary processes.
Seems a rather mundane example of the effects of human selection. What we’ve done to “domesticate” roses and orchids is pretty dramatic by comparison.
Yes, but the narrative is that mankind is a threat. To plants that just want to live free.
This concept easily explains why I can’t catch more fish.
This article just reminded me of the way I was taught about evolution back in grade school. We were told of an English forest that was inhabited by a dark speckled moth that was perfectly camouflaged on the birch trees, blackened by the heavy use of coal in the 19th to early 20th centuries. In the later part of the 20th century, after coal was largely replaced with electricity, the birch trees regained their natural white bark which made the dark moths more visible to birds and they were eaten out of existence, leaving behind the white speckled moths which were now the well camouflaged version. I guess it’s an argument in favor of “carbon pollution” if you’re trying to save the dark speckled moth.
Personally, and to expand use of the words across multiple fields and not just biology, I feel the term ‘evolutionary’ is very under used and in 95% of times should be used instead of the more click bait friendly ‘revolutionary’.
Technology does revolution its way into existence. It evolves based on what has come before.
If you want examples then let us talk naval. HMS Warrior was not revolutionary. It was the logical extension of military requirements and available tech. Evolution. HMS Dreadnought was not revolutionary. She was still a battleship using heavy artillery are the primary weapon. Evolution.
However successfully operating a submarine armed with torpedoes that can attack from below the surface of the water and hence forcing the development of new tactics, technologies and strategic options? A change that in practical terms took the existing methods of warfare and gave them a massive shake? Revolution.
Sorry, nothing to do with plants on hillsides, just a minor gripe on the use of words 🙂
Submarines were originally submersible motor torpedo boats, so the already extant motor torpedo boat destroyers were tasked with defeating them. Due to their being submersible, this mission did indeed require new sensor and weapons technology.
This sounds a lot like the supposed evolution of Darwin’s Finches. They turned out to have pre-programmed variability that allowed the Finches to change their beak design in a few years, anytime the vegetation changed on their island.
https://www.icr.org/article/darwins-finches-answers-from-epigenetics
Please don’t fall for creationist lies.
There is nothing “pre-programmed” about finch beak evolution. The observed changes are simply natural selection at work in species with short generation times, for vertebrates.
The traditional evolutionist view of Darwin’s Finches has been that it took many years for those mutations to occur and change the beak shape, with the original ancestor of the Galapagos Finches arriving around 2 to 3 million years ago. It had been universally accepted among evolutionists that these mutations take a very long time to occur. Yet when it was actually tested proved to be wrong. Rather, it showed that in a couple of generations you can have a group of finches change their beak size.
The “junk” DNA that had long been heralded as among the best proof of evolution, has turned out to be critical for a species, and researchers have realized that these are regulatory genes, that allow the species to adapt to changes, without having to somehow generate new information in their genes.
Which group do you think the evidence in this particular example, has shown to have been spreading falsehoods?
Prior to the long-term study by scientists who observed them over generations, it was not possible to say how much time was involved.
Those scientists never concluded what the liars at ICR claim. They did show that natural selection can work rapidly, as many biologists predicted.
There is no such thing as pre-programmed evolution. Selection works in response to changing environmental conditions.
So your contention is it’s not “pre-programmed,” it’s just that the genome has many alternate forms. One of the alternates may predominate given a change in environment? How does that differ from “pre-programmed?” I think you don’t like the implication of a programmer. Regardless, if the various morphologies are already in the genome and will manifest as appropriate, it would be better to claim that any evolution was done when the properties entered the genome. Claiming that they are evolving now is silly, perhaps “revolving?”
Evolution does occur everywhere, in every generation of living things.
Man-made climate change also happens on local and regional scales. Globally significantly, not so much.
BTW, being pedantic, I point out that humans are not the only multivores that eat plants.
Black bears where I live appreciate the ‘skunk cabbage’ plant in spring, eat berries from plants, and eat meat/fish too. Grizzly bears eat more meat/fish. (Polar bears are primarily carnivores but do eat berries and plants.)
(Wikipedia is really pedantic, classifying polar bears are ‘marine mammals’ because they spend much of their time on sea ice.
But I point out that while they are strong swimmers capable of long periods in the water, they usually stay out of it.
Yah, what about river otters, Keith? Though perhaps similar, as they move well on land – looking like a big weasel in motion, but forage in water. (Whereas sea otters are very limited in ability on land.)
I see variations in colour of mammal critters.
Cougars/mountain lions/pumas seem to vary somewhat in their shade, lighter in dry areas, darker in the wet coast rainforest.
Brown colour of black bears seems to be more common inland than in the dark forests of the wet coast.
Birds vary with location.
(Yes, I mean ‘wet coast’ – soggy in winter. 😉