"“People knew about these algae for a long time, but they didn’t think they were the closest relatives to the land plants because there’s an assumption that there’s a linear increase in complexity,” said Gane Ka-Shu Wong"
A theme in the writings of Stephen Jay Gould is that this assumption of linearity is absurd. He spoke often of "a bush, not a tree". These points are made particularly in his books "Wonderful Life" and "Full House".
4
So happy to read about something so interesting. The kinds of debates that surround a topic like this are very real and heartfelt to the participants, but they don't call each other "enemies of the people" or "human scum." By the way, is "human scum" an insult to humans or to scum?
11
How Did Plants Conquer Land?
And they will again...
This world's going to end soon.
1
If one thinks of tidal pools or estuaries where a lot of algae thrive, the difference between what is defined as land and what is defined as water starts to be become a bit difficult. For example, can you rule out the hypothesis that terrestrial plants were once seaweed that existed in a shallow pool that eventually became dry? So really the chain of events would be complex algae into aquatic plants and then terrestrial plants, no?
5
@C. M. Jones - Are you suggesting that other more robust hypotheses, perhaps even theories, are wrong, but your quite vague idea is the correct explanation?
5
Hold on there. The world was created in seven days just like it is today by Jehovah. While Jews, Christians and Muslims disagree about many things they all believe this. America is a democracy, so majority rules. Or at least we get to elect lawmakers who can then combat such glib bizarre "pseudo science" as this.
The writer is suggesting that our civilization and everything about it, is what, just the result of gazillions of random connections of elements, organelles, organisms that became plants, trees, animals and even cultures.
The writer and the readers of this "science" refuse to give praise to God, so he is getting ready to punish all such non believers. If it were really just random evolution that preceded us, it would require that most of them failed, not only species but entire civilizations would be overtaken by others
It's good thing that we don't realize that the death of civilizations is just a part of evolution. Rather than expecting it to be perpetuated by a God we don't believe in, let us exalt in the wonder of what we have experienced.
It's only times of crisis such as now that we realize the vulnerability of it all.
2
Did you hear about the fungus and the alga? They took a lichen to each other.
56
@C Lee Roo They were fun guys ?
8
Grammar tweak from introductory botany: "algae" is plural, "alga" is singular. A small thing, but the bar is set high for a Times science expert. Fungi carry a similar grammar pitfall.
5
@dhillier38 - There is added complexity as a single one-celled organism might be referred to as a singular object (alga), a singular species (alga or algae?) or as a general group of species (algae).
4
@dhillier38 I am not certain that one can carry a pitfall. Like most holes, it pretty much stays where it's dug.
8
Zimmer is a NYT treasure, always vivid yet accurate (not an easy combination). But he usually writes about the "outer" part of biology (how organisms relate to each other) and it would be nice to hear more about the equally fascinating and important "inner" part (the inner machinery of organisms, such as guts, phloem, kidneys, leaves and brains).
3
Minor correction to an excellent article: the Zygnematophyceae are in fact a class in the diverse Charophyte radiation.
6
I took two botany classes as an undergrad. And loved them both. I think I missed my calling.
2
Fascinating article. It would be interesting to know how and where the first genes came into existence and what their function was. Presumably, everything started there and evolved over time to what exists today.
6
@jpduffy3 My thoughts exactly, and another thanks to Mr. Zimmer!
1
@jpduffy3
Read “The Tangled Tree”. Great explanation of life’s origins.
Fascinating. The insights alone are worth reading (even if for no other reason than as a diversion from the deliberate complexity of politics). In the back of my mind, I kept thinking about modern technology while reading this. State of the art software is built from the simplest building blocks, developed generations ago for specific tasks. These blocks are then incorporated into the structure of the higher level code, not unlike algae stealing useful features from bacteria.
12
@Michael Cooke - Society is analogous. Products and services of a specific nature combine to form much more complex processes and services. Look inside the hardware of a smartphone. Each part can eventually be broken down into simply transistors. Over time, tech slowly evolved to grow bigger and more complex parts. Something like a CPU used to be considered separate things. Now, the main registers, the cache, and connectors are all acting as one unit.
4
Hmmm....
"This intimate connection (bacteria feeding on the carbohydrates) may have allowed genes from the bacteria to slip into the algae’s DNA, he speculated. It’s an intriguing idea — but a half-billion years later, hard to test."
Perhaps not, thought it might take time and effort. After all, the algae still exist today, yes? As do bacteria. Life is a dynamic process, and the last time I checked it's still going on today.
Is there perhaps a way to put the two components into a theoretically similar (to half a billion years ago) "petri-dish" then sit back and watch what happens? There'd be your proof.
In any case a fascinating article. Thanks for it.
John~
American Net'Zen
5
@John - Why do you think those original bacteria and algae still exist? Their respective species could have gone extinct long before the dinosaurs came along.
3
Wonderful photograph
5
I love these science articles.
I love the comments written about these science articles
Thanks, guys, for keeping me smart.
33
@sjs I loved it too. Just a note: Some of the "guys" who authored the article are gals.
14
@sjs We happy commentators should be giggling with self respect.
3
This is a really complex subject that covers lateral gene transfer/transfection, exaptations, plastids, and a lot more but Carl's article sums up the situation fairly well without going down the rabbit hole of evolutionary biology. Plus it's algae and plants so while I like algae botanists go into too many Divisions for me.
Algae are much more simple and tasty, in my opinion.
The link to the primary article allows one to go further, though, and the Intro & Abstract for "Embryophyte stress signaling evolved in the algal progenitors of land plants." (one of the references) helps to flesh out the work that's involved in making conclusions like this.
In the future I'd like to see more articles concerning the molecular clock and evolution. While the rest of the world is consumed by competition and resource acquisition the breakthroughs made by geneticists and biologists verge on explaining our whole world.
Interesting times indeed!
35
"How Did Plants Conquer Land?"
Had to have been colonialism.
9
I keep wondering in my Science Fiction imaginings why we can't develop floating forests.
2
@Just Me - Seriously, how can you expect others to propose solutions for something you imply has obvious solutions? If the thing is so obvious, describe it.
Present your detailed model. How will the forest remain buoyant? Will you use a sealed support vessel, which then prevents drainage into underlying structure as with real forests? Or, will the forest only lose water through evaporation? If that is the case, you end up with toxic accumulation of salt and metals. How will you maintain structural integrity of the "raft" holding up the forest? Currents, waves, and wind will present stresses, as well as unequal loading of mass. What about heavy rain events? Will they flood and sink your forest raft? What about the ecology of the body of water? How will your floating forest affect the water by blocking it from atmospheric heat transfer, evapotranspiration, and even sunlight?
2
I recently finished reading The Tangled Tree by David Quammen. This article builds on a number of reveals in the book. Fascinating!
10
@Jordan Totally agree. Carl and David Quammen have joked that they talked about their respective books - Carl's on human genetics, and David's on gene transfer, before publishing.
Horizontal "journalism" transfer?
7
Excellent. One minor question. Are not the sub surface fungi, bacteria, and viruses far more in mass than the plants on the surface and their roots?
8
Fabulous work. Thank you for reporting it.
17
I suspect that the millions of years of deaths of algae on land helped create the soil that would later become necessary for plants.
12
@VJR
I think it was mostly worms that broke up continental rocks into sand-size chunks. Of course they fed on the algae and re-deposited it in fertilizer form.
3
@Dan K
Any Geology 101 course would tend to suggest otherwise.
9
@isotopia yeah, glaciers helped a lot, wind & waves, orogeny and friction from colliding land masses. Friction in rivers at high flow makes some smooth rocks.
I think I heard one geology teacher say it took three trips from mountain to beach to make sand-sized particles.
3
It was truly a milestone for life when plants colonized land. We are witnessing an equally momentus colonisation today ... when life leaves Earth and colonizes the solar system. We tend to think of the benefits that will come in terms of years and centuries. The benefits are better thought of in terms of 100 million years, when evolution has had time adapt life to the environment of space.
7
@Adrian Maaskant - I note that one thing about milestones. They are only markers. When you run a marathon, every step counts equally, even if there is a huge marker erected at the half-way point.
5
As a geologist who has walked many miles over bare rock in the Canadian tundra and elsewhere, trying to see underneath extensive multicoloured crusts, I have always been astonished by the tenacity, toughness, and ubiquity of lichens. While the algae discussed in this article may have indeed evolved to modern plant forms, that does not mean it was the first to colonize land. Disappointing that this article said nothing about a symbiotic algae in a lichen being perhaps the first photosynthesizer to make that leap. ‘Til shown otherwise I will like to think that I spent countless hours alone with the land’s first inhabitants, eking sustenance out of some of the earth’s oldest rocks.
37
@Tony Peterson was surprised (but not astounded) to learn that lichen have not one, but two symbiotic fungi.
3
@Still here Lichens are a symbiotic combination of algae and fungi.
4
@Tony Peterson
There is recent work that suggests lichen are a late-comer in terms of colonizing the land:
https://onlinelibrary.wiley.com/doi/abs/10.1111/gbi.12369
It is easy to spin a story how that might be true, in that lichens are in the most inhospitable terrestrial environments, so it might have take time to form the symbiosis that adapted them to these environments.
6