Leaves have evolved at least twice 🤔
from fossilesque@mander.xyz to science_memes@mander.xyz on 07 Jun 23:02
https://mander.xyz/post/31618743

#science_memes

threaded - newest

Dasus@lemmy.world on 07 Jun 23:15 next collapse

“Son, if you’re interested in biology, you’ll have to learn to understand that the definitions of terms are rather… loose.”

en.m.wikipedia.org/wiki/Species

MadMadBunny@lemmy.ca on 07 Jun 23:17 next collapse

So, timey-wimey, but with plants?

Dasus@lemmy.world on 07 Jun 23:19 next collapse
theunknownmuncher@lemmy.world on 07 Jun 23:24 collapse

Yes, but not just plants

ryedaft@sh.itjust.works on 08 Jun 06:33 collapse

But especially with plants

plenipotentprotogod@lemmy.world on 08 Jun 03:20 collapse

Looks like it’s time to post my favorite SMBC again

[deleted] on 07 Jun 23:20 next collapse

.

HowAbt2day@futurology.today on 07 Jun 23:47 next collapse

69, son. 69.

ChicoSuave@lemmy.world on 08 Jun 00:08 next collapse

Nice, dad. Nice.

propter_hog@hexbear.net on 08 Jun 01:53 collapse

Nice

Midnitte@beehaw.org on 08 Jun 00:30 next collapse

At least once

loomy@lemy.lol on 08 Jun 01:11 next collapse

Ask your school teacher tomorrow.

TropicalDingdong@lemmy.world on 08 Jun 01:19 next collapse

Integumented indehiscent mega sporangium with one functional megaspore?

Once.

But once is all you need.

radix@lemmy.world on 08 Jun 01:45 next collapse

Which came first, the plant or the seed?

P4ulin_Kbana@lemmy.eco.br on 08 Jun 03:00 next collapse

The original comic was drawn by Chris Halberk, if I’m not mistaken.

Ephera@lemmy.ml on 08 Jun 04:42 next collapse

I recently figured out that wheat/gluten FUBARs my health, so even just the concept of cereal grains has recently exploded in complexity in my head.

Before, I was eating:

  • wheat (incl. durum, spelt, rye, and rarely barley, emmer)
  • oats
  • rice

Now I newly eat:

  • buckwheat
  • millet
  • quinoa (in like three different colors)
  • amaranth
  • whole-grain rice is apparently pretty cool
  • maize/corn (in the form of polenta and tortilla)
lb_o@lemmy.world on 08 Jun 14:54 collapse

Buckwheat is so good if you fry onions, carrots and bacon, and then mix with boiled buckwheat.

Also if you don’t use multi-cooker - consider. It is a bit hard to get used to, but gives additional freedom in cooking everything from your list with meat.

Ephera@lemmy.ml on 09 Jun 00:44 collapse

Well, I happen to separately only eat foods that don’t cast a shadow do the vegan thing and my genes don’t like the taste of onion either, so uhh… 😅

But still good info. I haven’t yet tried cooking whole-grain buckwheat myself, so knowing a combination that works, I can figure out substitutes or other combinations which are likely to work.

southsamurai@sh.itjust.works on 08 Jun 05:35 next collapse

The answer to any question like that is: I have no idea, but we’ll try and find out tomorrow. And if we can’t, that’s okay.

Sirius006@sh.itjust.works on 08 Jun 21:21 collapse

The “if we can’t, that’s okay” is really nice to add. I’ll try to keep it in mind. My 4yo tends to become frustrated when we can’t keep our words.

RQG@lemmy.world on 08 Jun 07:30 next collapse

Isn’t evolution a constant process instead of happening in steps?

lugal@sopuli.xyz on 08 Jun 10:05 next collapse

I think the question is how often it evolved independently like bird and bat wings evolved independently

RQG@lemmy.world on 08 Jun 13:05 next collapse

That makes a lot more sense then. Thank you, happy to learn something new.

petrol_sniff_king@lemmy.blahaj.zone on 08 Jun 20:11 collapse

I forget where I saw this, but trees are kind of like crabs, in that they’ve convergently evolved many, many, many different times. Pretty interesting!

Geodad@lemmy.world on 08 Jun 14:30 next collapse

Also pterosaur wings.

Korhaka@sopuli.xyz on 08 Jun 19:43 collapse

Add flying fish to that.

vala@lemmy.world on 08 Jun 23:29 collapse

Ohh I also misunderstood the question.

The term for what your talking about is “convergent evolution”.

en.m.wikipedia.org/wiki/Convergent_evolution

flora_explora@beehaw.org on 08 Jun 10:14 next collapse

Hm, I was intrigued and looked at the evolution of plants. This made me realize how paraphyletic gymnosperms and angiosperms really are! We just don’t know how angiosperms exactly started out and if they might be monophyletic. And in case of gymnosperms, they are consisting of many very different plant groups that evolved independently.

So gymnosperms were probably the first plants to evolve seeds and they “include conifers, cycads, Ginkgo, and gnetophytes, forming the clade Gymnospermae”. That doesn’t really give an answer but that’s the best we can do?

It was previously widely accepted that the gymnosperms originated in the Late Carboniferous period, replacing the lycopsid rainforests of the tropical region, but more recent phylogenetic evidence indicates that they diverged from the ancestors of angiosperms during the Early Carboniferous.[12][13] The radiation of gymnosperms during the late Carboniferous appears to have resulted from a whole genome duplication event around 319 million years ago.[14] Early characteristics of seed plants are evident in fossil progymnosperms of the late Devonian period around 383 million years ago. It has been suggested that during the mid-Mesozoic era, pollination of some extinct groups of gymnosperms was by extinct species of scorpionflies that had specialized proboscis for feeding on pollination drops. The scorpionflies likely engaged in pollination mutualisms with gymnosperms, long before the similar and independent coevolution of nectar-feeding insects on angiosperms.[15][16] Evidence has also been found that mid-Mesozoic gymnosperms were pollinated by Kalligrammatid lacewings, a now-extinct family with members which (in an example of convergent evolution) resembled the modern butterflies that arose far later.

Wow, so there was already pollination going on before flowering plants even existed??? By scorpionflies who’s ancestors I frequently see? And there were butterfly-like insects long before real butterflies existed? Look how butterfly-like they were! This is wild!!

olafurp@lemmy.world on 08 Jun 11:53 next collapse

Good question my son, define “seed”

Diplomjodler3@lemmy.world on 08 Jun 12:07 next collapse

Sigh *unzips*

SkaveRat@discuss.tchncs.de on 08 Jun 16:05 next collapse

ಠ_ಠ

Diplomjodler3@lemmy.world on 08 Jun 16:11 collapse

What? I’m just giving a practical demonstration.

Stomata@sh.itjust.works on 08 Jun 17:39 next collapse

:-\

lars@lemmy.sdf.org on 09 Jun 10:25 collapse

( ͡° ͜ʖ ͡°)

TropicalDingdong@lemmy.world on 08 Jun 19:26 next collapse

A seed is an integumented indehiscent megasporangium with one functional megaspore.

It doesn’t have an ambiguous definition, and we know, without any uncertainty, that it evolved precisely once.

OsrsNeedsF2P@lemmy.ml on 08 Jun 19:49 next collapse

Can you translate that to English

Klear@lemmy.world on 08 Jun 20:22 next collapse
TropicalDingdong@lemmy.world on 08 Jun 20:29 collapse

Somewhat, but keep in mind, its a half decade of study to develop the understanding. Also, trying to create parallels between how plants do sex and how animals do sex, thats going to throw you off. Plants do sex in a fundamentally different way than how animals do sex.

The basic trajectory in the evolution of land plants has between towards additional layers around the gametophytic generation, and additional investment in that generation. Animals, like us, have a unicellular gametic generation (sperm and eggs). Plants, well, its complicated… Basically, when plants first came onto land, the haploid, gametic generation was the “big obvious plant” thing, but that switched at a certain point. So its just not possible to map plant evolution onto animal evolution.

Early land plants invested very very little into the next generation. It was all spores, single cells, which then had to establish themselves without any support from the parent generation. But the haploid generation was the dominant plant part. These plants are still with us today in the form of mosses and liverworts.

In liverworts and mosses, its still the N generation that is the dominant plant part, and the 2N generation is totally dependent on the N generation. This all got flipped on its head when plants developed vascularization, and the 2N generation became the dominant plant part.

PLANT EVOLUTIONARY TIMELINE FOR SEED COMPONENTS

| MYA   | Evolutionary Step                 | Seed Component         | Definition                                                      | Dominant Plant Body |
|-------|----------------------------------|------------------------|------------------------------------------------------------------|----------------------|
| ~470  | Earliest land plants              | —                      | Non-vascular; liverwort-like                                     | N (haploid)          |
| ~430  | Vascular tissue appears           | —                      | Enables upright growth, fluid transport                          | 2N (diploid)         |
| ~420  | Sporangia                         | Megasporangium begins  | Spore-producing structures (seen in Rhyniophytes, Lycophytes)    | 2N                   |
| ~410  | Heterospory                       | Functional megaspore   | Plants make large (mega) and small (micro) spores                | 2N                   |
| ~385  | Runcaria                          | Integument precursor   | Fossil shows integumented megasporangium, no fertilization yet   | 2N                   |
| ~365  | Seed ferns (Pteridosperms)       | Ovule (true seed)      | Integumented, indehiscent megasporangium with 1 megaspore        | 2N                   |
| ~360  | Early gymnosperms                | Full seed              | Retained embryo + full protective tissue                         | 2N                   |
| ~320  | Gymnosperm radiation             | —                      | Conifers, cycads diversify                                       | 2N                   |
| ~140  | Angiosperms (flowering plants)   | —                      | Double fertilization, fruit, enclosed ovules                     | 2N                   |

olafurp@lemmy.world on 08 Jun 21:30 collapse

This, and your explanation below is fantastic. I had no idea that this was known and thought it plausible to have evolved many times like crabs.

Also, name checks out

vala@lemmy.world on 08 Jun 23:26 next collapse

Also define “evolve” in a way that can be quantized like this.

Reddfugee42@lemmy.world on 08 Jun 23:37 collapse

“How to Jordan Petersen your kid”

azi@mander.xyz on 08 Jun 13:57 next collapse

Leaves evolved more times if you include blades of algae

Geodad@lemmy.world on 08 Jun 14:29 next collapse

The correct answer is, “We don’t know son. You could become a paleo-biologist and be the one to figure it out!”

Tollana1234567@lemmy.today on 08 Jun 21:42 collapse

Depends on what you mean by leaf, some plants has phylloclades, which is the widened stem to look like leaves. You can see this in acacia trees, you see those tiny leaflets those are the actual leaves on the stem