This has been bugging me lately. Which came first, plants or animals? Do plants and animals share a common ancestor? Thanks, SD!
Since Led Zeppelin date back to 1968, while Dr. Teeth and the Electric Mayhem first appeared in 1975, I’d say Plant came before Animal.
He he, but I’m looking for a serious answer, guys. Thanks!
It’s not really known which came first in the ocean, but plants made it to land first. It wasn’t until there were land plants that animals started coming ashore. There were a lot of ocean animals long before plants made it to land though.
What Fubaya said. Land plants date back to the Silurian period, sometime around 430 mya, if you want something more than molds. Earlier if you’re willing to stretch your definition of plant to include that mold. Land animals appeared sometime later, around 420 mya.
From another perspective, however, eukaryotes were around and doing just fine before some of them recruited a primitive algae for use as chloroplasts. Or, to put another way, the cells that would evolve into animals were already around and somewhat diverse before some other cells gained photosynthetic organelles. None of these things would be considered a plant or animal in common parlance, but this does leave plants as more relative newcomers.
And to answer the second question, any two organisms on Earth have a common ancestor, if you’re willing to go back far enough. We’re all related.
It’s entirely dependent on your definition of “plant” and “animal”.
Insofar as all animals are descended from photosynthetic ancestors, then plants came first. In fact you could argue that animals are just highly specialised plants. However since those photosynthetic ancestors were bacteria they won’t meet some definitions of plant.
And that’s the whole problem. What exactly is a plant? Most people would say that kelp is plant, but by many definitions it isn’t even in the same kingdom. Similarly sponges aren’t something that most people would consider to be an animal, yet they.
Don’t leave us in suspense, man!
…are really the loathsome spawn of dread Cthulhu.
Wasn’t it obvious?
Single cell, non-nucleated organisms were first (bacteria and archaebacteria). Some of these discovered photosynthesis (cyanobacteria). From the symbiosis of non-nucleated bacteria and archaebacteria arose eucaryotic single cell organisms containing a cell nucleus and organelles such as mitochondria (found in plants and animals) and chloroplasts (in plants only). From those arose multicellular organisms. It is thought that multicellularity developed separately for plants and animals.
They are? Cite.
I say the edge goes to “Plants” over that which you’d consider the "Animalia’ kingdom.
Taking a look at the trees, you can see that the Opisthokonts(Animals and others) came a bit later than the Archeoplastida(plants).
They did share apparently a common Eukaryotic ancestor though, so i wouldn’t go so far as to say that Animals are highly specialized plants, but rather animals are specialized eukaryotes, which split off early enough from the highly specialized eukaryotes that would become plants.
The very first bacteria-like organisms were very likely not photosynthetic, but rather chemosynthetic.
If by “plant” you mean an organism that is capable of photosynthesis, and “animal” an organism that isn’t, there were living things that existed before the evolution of photosynthesis.
Or maybe you mean Eukaryotes? The ancestors of modern day multicellular plants evolved from eukaryotic protozoans, same as modern day animals. But before there were multicellular plants and animals, there were single celled eukaryotes. And it seems pretty certain that the first of these eukaryotes weren’t photosynthetic. Eukaryote chloroplasts seem to be an endosymbiont. One day a eukaryotic protozoan ate some photosynthetic cyanobacteria, but instead of being digested they took up residence and started living inside the protozoan. And those cyanobacteria eventually became plant chloroplasts, the organelles inside plant cells that carry out photosynthesis.
If we consider the first protozoan to incorporate cyanobacteria endosymbionts as the first plant, then that protozoan had animal-like or fungi-like ancestors that ate other cells. So in that sense, animal-like protozoans predated plant-like protozoans.
If we’re talking about multicellular organisms, I don’t know if we know for sure whether multicellular animals or multicellular plants came first. It seems pretty logical to me that colonies of photosynthesizing cells would work better than ones that don’t but I don’t know if there’s any evidence either way.
And if we’re talking land plants vs land animals, plants emerged on land first.
That’s not quite how cladograms work. You’re only looking at shared common ancestor branches, there’s no time scale involved. So it’s possible that the basal archaeplastids chug along undiferentiated while the Opsithokonts differentiate down to Metazoa (Animalia) within a short span, way before Plantae(which are the plants, not Archaeplastida) differentiates.
Personally, I do agree that it’s likely from fossil evidence that algae evolved before any metazoa, given the long time period between the likely algae Grypania and the Roper algae and the Ediacara fauna.
Note, I’m going by plant and animal sensu stricto here, although I think the scheme works for lato too.
Even if you don’t like Richard Dawkins’s take on religion (and I don’t, even though I am a thoroughgoing atheist), his book, The Ancestor’s Tale is wonderful and makes the point as clearly as possible.
Actually, the best evidence for common ancestry is the common DNA code. As far as anyone has been able to determine, the connection between codons and the amino acids they code for is completely arbitrary and therefore the only cure for the common code is common ancestry.
So what are single celled organisms classified?
Plant or Animal? :dubious:
I know some live by photosynthesis and some eat other single cells, if at not least having some sorta cellicidal tendencies.
Then there is the Virus…there is a microcosm of em…
seems algae was first, as a verifiable land or sea community though…
Generally, neither. One can describe all of life as belonging to one of six kingdoms: Archae, bacteria, protozoans, fungi, plants, or animals. The definition of “animal” requires that the organism be multicellular, and most definitions of “plant” do so as well (though some consider some single-celled algae to be true plants). Things that would popularly be considered “single-celled animals” (or “single-celled plants”, if you don’t consider them true plants) are mostly put into the protozoan kingdom, which is a sort of catch-all miscellaneous category for eukaryotic organisms that aren’t plants, animals, or fungi.
Oh, and since you mentioned viruses, they aren’t put into any of the six kingdoms of life, because they’re not quite precisely considered “alive”. Biology, as a rule, is a messy subject, and there are no hard-and-fast definitions for anything, so it’s not surprising that you end up with some things that are almost-but-not-quite alive.
To expand a little on what Chronos said, the “two kingdom” scheme of shoehorning everything into “plants” and “animals” is long outmoded. When I was a kid, bacteria were considered to be a primitive form of fungi, and fungi were considered to be plants. In the 1960s taxonomists realized that there was much more complexity to it than that, and four, five, and now six kingdoms have been proposed. At an even more basic level than kingdoms, the three “domains” of archaea, bacteria, and eucaryota were recognized.
However, none of these systems is really cladistic. The kingdom of “protists” (one celled eucaryotes) in particular is polyphyletic. It includes enough diversity that probably a dozen or more “kingdoms” could be recognized within it, each of them as different from one another as multicellular plants, animals, and fungi are.
So, can we tell a difference between the two single cell protozoa as.
1: Plant like - stationary, dinner or mate comes to it by chance. (wind, climate)
2: Animal like - has motor skills to look for dinner or mate. (able to move from bad area)
3: Viral like - has to come afterward, since it needs to inhabit something to replicate, can’t very well do that on its own.
Just a question.
Seems that the functions of Plant like should come before Animal Like.
Nope. Many protozoa are active predators, but they still have chloroplasts and are capable of surviving by photosynthesis is needed. Many stationary protozoa are incapable of photsynthesis while the vast majority of photosynthetic protozoa are highly mobile.
There’s no obvious line we can draw here.
The problem is that predatory motility and photosynthetic ability go back as far as the bacteria at least. IOW the features you use to characterise “plant like” and “animal like” predate the protozoans by a few billion years.
The thing is that the first organisms were eating non-living material, whatever that may have been. The next level of evolution would have been organisms that ate other dead organisms. Then organisms that killed and ate other organisms. Photosynthesis arrived on the scene very late. So in that respect “plant like” arrived much later than “animal like”.