Horizontal gene transfer occurs routinely among bacteria through a process called conjugation. Bacteria literally inject their neighbour with a chunk of DNA.
This is what the molecular apparatus looks like from the surface membrain of a bacterium.
You are indeed correct to point out that the article is about two eukaryotes which are vastly different organisms, separated evolutionarily from bacteria by hundreds of millions of years, or billions of years, depending on how you measure it.
Similarly, humans are quite different from whiteflies, although the difference is put into perspective when you consider that we have something like 40% commonality of genes, depending on how you map homologues.
How the plant gene got into the whitefly is a deep mystery that happened long ago.
If we go back even further in evolutionary history, insects, humans and other eukaryotes are descended from prokaryotes. The organelles of eukaryotic cells such as the mitochondria of animal cells and the chloroplasts of plant cells were once individual prokaryotes which merged into colonies and formed eukaryotic cells through endosymbiosis.
Even today, eukaryotes live symbiotically with prokaryotes in a way that is impossible to disaggregate. You have as many prokaryotic cells living inside of your shirt and pants as you do eukaryotic cells, with trillions of gut bacteria responsible for keeping you alive by pre-processing the food you buy from the supermarket and restaurants into nutrients and amino acids that your actual body can utilise.
Whiteflies also have parasitic and symbiotic commensal bacteria that are integral parts of their organism. Perhaps one of those gut bacteria, or a respiratory parasite transferred that plant gene millions of years ago in a freak occurrence. Or maybe it happens regularly and systemically.
With gene sequencing only becoming widely available in the last decade, scientists are just beginning to isolate and identify examples of gene transfer like the one in this article.
> Even today, eukaryotes live symbiotically with prokaryotes in a way that is impossible to disaggregate.
Don’t forget mitochondria, the cellular organelles that are responsible for cell respiration:
> Mitochondria and chloroplasts likely evolved from engulfed prokaryotes that once lived as independent organisms. At some point, a eukaryotic cell engulfed an aerobic prokaryote, which then formed an endosymbiotic relationship with the host eukaryote, gradually developing into a mitochondrion.
There are many cases of horizontal gene transfer involving eukaryotic cells, although usually the donor would be a prokaryotic cell or a virus.
The bacterial residents of mealybug have lost the ability to make crucial proteins, and instead rely on the mealybug to produce them. It never had those genes in the first place, obtaining them instead through HGT. It's thus posited that eukaryotic organelles such as mitochondria and chloroplasts transferred genes to their hosts as well.[0]
They are more complex, but the cell type doesn't matter as much. In fact, there are bacteria that cause disease using HGT (https://en.wikipedia.org/wiki/Agrobacterium). Modification of those bacteria is how you get low-cost plant genetic engineering.
HGT is also common amongst soil fungi between bacteria and fungi. In fact, when certain mycorrhizal fungi are placed in high-stress environments, the rate of HGT increases. It's not really understood what mechanisms cause this, but it seems to be an adaptation to quickly adapt and evolved to a new environment by borrowing genes from other soil organisms
we've been on the cusp of a huge revolution in genetic engineering for 20 years, and will be for at least another 20 years. It's entirely unclear that our newest capabilities will make a significant difference outside of research labs.
We were on the cusp 20 years ago with human genome project, and now things have settled down, gotten boring, and the next cusp is like 20-30 years from now.
Honestly aside from crispr not much has changed since 10 years ago (and I know this is sacrilege on hn but crispr is not that exciting outside of making some lab techiques easier and maybe enabling human germline editing, which it sees no one does).
I'd agree. 20 years ago comments like "we'll have the evolutionary tree of life (or even small clades) resolved in 5-10 years" were routinely tossed around. Today the reality of the vastness of the biodiversity, the complexity and limitations of the genome (homoplasy, etc.), limitations in compute power (it takes weeks to run single evolutionary reconstruction analyses), and the and practical inability to scale to 10s of thousands of organisms (things like basic project-tracking software are required) remain huge bottlenecks. Furthermore those "genomes' we have, even outside a handful of model organisms, are more or less raw data, not annotated, confused jumbles of pipe-line derived data that require years to fully grok, refine etc. I suspect we have decades to go before the collective "genomic" enterprise will be "fully operational".
hm. I somewhat disagree. We basically have the evolutionary tree of life done. There are probably a few surprises still. 90% of stuff, it turns out, is the same. We don't know what causes detailed differences, (like what is different between a dog and a bear?) but for a lot of interesting tasks: "get a picture of how X gene is regulated", "understand how X molecule is biosynthesized" are basically solved, solvable, or there is a worked out procedure to solve it, using sequencing... The problem is that we don't have operators smart enough to know how to use these data carefully. If you are a detail-oriented biochemist who has a good grounding in first principles, you basically have everything you could need out of genomics. However, that won't be enough to get a faculty position!
As a point of reference I'm currently a Co-PI on a grant to recover the phylogeny of a hyper-diverse group of insects.
As to your first point- we are nowhere close to a complete evolutionary tree of life (assuming we could come up with what "complete" means). I agree we have good estimations of some basic major splits, but many things are in flux. Early origins? "Kingdom" classifications change multiple times each year still.
Your second point (aside from "people are dumb", which doesn't really hold) is not about evolution, and I'm not experienced enough to make a judgement. I strongly doubt, however, that the full capacity of "compute" you need to actually do genomics, is anywhere near enough to answer everything we'd want to. Today you need a full team of support, not just one person with grounded first principles (which I agree is often missing, but it's also required of more than one expert type).
I guess if you're an evolutionary biologist the thing is that there will always be more to discover from a genomics perspective (so it's a bit of a search for smaller and smaller), but if you step back and do quantitative analysis of the structure of the tree of life I think it will be the case that what we discover in the next 100 years is not going to be as dramatic as what we have learned in the last 100. Big shifts (like archae; my grad school boss discovered that methanogens are archae) came before genomics even! And while they are still some surprises, they are increasingly on the edges.
For many things you probably need to only do a blast search. for example, I identified candidate mutations in an enzyme one combination of which dramatically improved the output by carefully doing a blast search. Likewise, my postdoc boss basically figured out an entire small molecule biosynthetic pathway with ~ a day's worth of blast searching.
To understand transcriptional networks, you can get really far with qpcr, or if you want to get really old school yeast-two-hybrid, both of these impossible without genomics.
We have total organism knockout Libraries in yeast and e coli that are powerful tools, and have a genome that we've minimized to sub-500 genes. Yes there's 100 or so that we don't understand (mostly short transmembrane proteins that honestly probably need to be there in bulk just to maintain tonicity). These are just the projects I've directly worked on or been a fly-on-the-wall on.
Anyways, point is most of the really bid things that the genomics revolutionized have been ticked off. There's still a lot to do, obviously, but I think we know more than you're giving credit for. It does nobody a service to treat biology as a mysterious black box that will never be penetrated.
Can make new dna baby I sjouke say it is revolutionary something I do not like and want but still is revolutionary. And evolutionary if the kids grown up and “reproduce”.
And other like pig and monkey resulted from same technique.
The paper is pure science. I’d argue that the Life Sciences are entering a Scientific Revolution 2.0. We are on the cusp of learning how many living systems work. The scope is broader than genetic engineering alone, IMO. This revolution is shaping up to be multidisciplinary; computation will be a critical aspect.
Agreed and I think the manipulation of gene and rna is revolutionary. It might be just steps and tools. But if not control, do we still have human is an issue.
Making a profit from gene technology is hard. I've heard second hand that many famous and innovative biotech companies have barely been able to turn a profit, year after year.
I can't find it back but there was a blog post explaining that earth plants could have been red instead of just green.
Do you imagine red forests??
And this is not science fiction at all, brown and red photosynthesis can be as efficient hence why it is very common underwater.
However some contingent "choices" have been made at the origin of photosynthesis and no terrestrial plant has preserved the necessary gens and such gens cannot be developed back. However horizontal gene transfer might be a hope of seeing one day a red planet (though a human made OGMs is likely the best strategy)
I remember the "Carniferns" from SimEarth and the idea of a plant/animal hybrid is very appealing. I can imagine a distant future where a durable engineered hybrid could be put to use for terraforming.
Reading the paper, I don't understand why the authors conclude that horizontal gene transfer is the most likely explanation, and not independent evolution.
This is based on gene sequence comparisons.
The gene in question is closely related to its plant counterpart and phylogenetically distant to any other known insect genes.
So the most parsimonious explanation is that the gene is horizontally transferred from plants to insects. The chance that it has evolved independently from another insect gene is very, very low.
They assumed HGT because they couldn’t find any ortholog phenolic glucoside malonyltransferase genes in related whitefly species, eliminating convergent evolution as a possible explanation. In addition, the phylogenetic analysis showed that the BtPMaT1 gene clustered with other similar plant genes.
> Makes me think if all those insets that mimic plants are really just a matter of adaption and evolution or they got some plant genes.
If you mean insects that look like plants, then no. The genes that control and influence morphology are completely different (in theory a gene for something like a pigment could transfer, but I'm not aware of any examples).
But if you mean insects that, for example, smell/taste like plants (either to plants being eaten, or to other insects), then maybe. But a common strategy that achieves this is for the insect to just store whatever compounds they need from plant material they eat, and that doesn't require gene transfer.
Hardly. Horizontal Gene Transfer is an important mechanism, especially for bacteria, but only adds an interesting wrinkle to the neo-Darwinian modern synthesis (which has been incorporating additional aspects from various subfields of biology episodically since it was first articulated):
I would read the article as if the transfer was a a random event, :
But how the whitefly managed to swipe a plant gene is unclear. One possibility, says Turlings, is that a virus served as an intermediate, shuttling genetic material from a plant into the whitefly genome.
Right, but there’s a difference between random events causing biological changes vs. random mutations having to happen during reproduction/birth and proved out in the form of natural selection.
From evolutionary point of view it is semantical why genome changed. Also I’ve never heard of any biology textbook or journal claiming mutations would only happen during reproduction or birth. Mutations happen all the time, that’s one reason we have diseases like cancer. Your reproductive cells can mutate any time throughout your life passing out differences to offspring. There is also genetic recombination bringing out traits that didn’t exist, or suppressing ones that do.
It's hardly semantics. Many people over the past few hundred years have found it mind-bogglingly unlikely that organisms can evolve to be so purpose-built to survive in their environments if the only input driving that forward is the circumstances of their birth and the sheer number of organisms being produced. This study suggests that's not the only way these genetic changes happen, which makes the premise of evolution much less unlikely.
> It's hardly semantics. Many people over the past few hundred years have found it mind-bogglingly unlikely that organisms can evolve to be so purpose-built to survive in their environments if the only input driving that forward is the circumstances of their birth and the sheer number of organisms being produced.
That's really just a failure of imagination. Also, it ignores that the mechanisms of evolution have themselves evolved.
Sure, evolution seems unlikely if you assume discrete genes have to change in lockstep to adjust traits successfully (eg. if you assume that separate changes are needed to adjust bones, muscles, skin, nerves, etc. to lengthen a limb), but that isn't how our bodies wirk (if it was, it would be nearly impossible to heal from an injury), nor is it how genes control that development.
Instead, you have genes that control things in less direct ways, such as body to limb ratio, and other genes that direct development of things like muscles in relation to bones and joints don't have to change at the same time for everything to keep working.
Even that's an overly simplified model, but you should get the general idea. You might like to read the book "The Plausibility of Life", which goes into more detail.
> there’s a difference between random events causing biological changes vs. random mutations having to happen during reproduction/birth
From an evolutionary perspective, there are none. Both are but sources of variation (the actual cause does not matter) in the genome; which, depending on their impact, may or may not get fixated by natural selection.
Even if you look only at random genetic mutations, these are being inserted into an incomprehensibly large dynamical system with its own selective pressures. It’s a distributed computation at such a massive scale, you would never have any hope of fully stimulating or predicting its outcome. So I’m not sure what you mean by “just random trial and error”.
We don’t really have a good definition of random to start, but we can say things are more or less random than other things. When people say evolution is entirely due to “random mutations,” I would argue that’s misleading, because it’s less random than arbitrary bit flips. If an entire chunk of a gene from an already-evolved organism can enter at any time, that in my opinion is less random than the bit flips hypothesis. And sure, people in this thread can say this is old science, but my point is around the popular understanding of evolution and how it is communicated to students and the general public. It’s less random than total randomness, and many people completely deny it.
Not sure why you're being downvoted, I understand you perfectly well.
To clarify for others: random gene mutation within an organism is not the same a random gene introduction from external source.
Take something like an Orchid Praying Mantis. If it were discovered that the Orchid Praying Mantis got some of its coloring from a gene transfer of orchid plants with which it cohabitated, that would remove an enormous amount of random mutations that needed to have occurred within its own genome to achieve that goal.
Nobody is saying that the mantis wouldn't be subject to all of the same forces of natural selection thereafter, or that the particular gene that was transferred wasn't itself a random selection from the orchid. It just makes the arrival at certain gene configurations immeasurably more likely than they would've been within the same time period, given an organism's lineage had only had its own random mutations available.
HGT is fascinating & important, but it’s also completely accepted, recognized, and studied.
Horizontal gene transfer was actually discovered before we had any consensus that DNA was the biological mechanism of heredity, and the experiments showing evidence of HGT were used as evidence for that claim.
Can't be trial and error. There is no guide. Thus there is no trial.
There is simply natural events or circumstance incidentally causing the death of individuals in environments for which they are unsuited before reproduction.
Trial is defined as "a test of the performance, qualities, or suitability of someone or something." An organism's life is definitely a test of its ability to survive; a flower seed being buried in a shady spot is thus a trial. There is no need for a guide.
No one is testing, however. Folks commonly use verbiage derived from intellectual design, and we should be conscientious on the subject. There is a system in the randomness, but we need not attribute will to the system.
There need not be a tester for a test to exist. The organism tests itself in some sense. The system (universe) tests the organism, the same way things can stand the “test of time.” Whether you personally interpret this as intelligent design is entirely outside of the discussion.
This is what the molecular apparatus looks like from the surface membrain of a bacterium.
https://youtube.com/watch?v=ihlFqOK5cZM