2007-03-27 10:12:25 · 8 answers · asked by Nessa 1 in Science & Mathematics ➔ Botany
I think people are getting confused about the evolution of photosynthesis vs. the evolution of land plants. The previous answers mostly correspond to the evolution of photosynthesis in bacteria and archea. Land plants didn't evolve until much later in the Ordovician . . . or between 450-500 million years ago.
2007-03-27 10:59:38 · answer #1 · answered by plantgirl 3 · 0⤊ 0⤋
There is no exact known date, but if you're asking about land plants (as oppose to marine algae), then the rough date would be something like just over 400 million years ago, before any animal walked on land (including insects). Plants' invasion of the land only happened because of certain key adaptive features, like a waxy cuticle around exterior cells and the evolution of a sporophyte generation (which algae don't have). And in case you're curious, seed plants didn't evolve until many millions of years later, and flowering plants entered the evolutionary picture around 80-70 million years ago, during the hay-day of the dinosaurs. However, they really took bloom, so to speak, and diversified once the dinos went extinct - with the exception of the avian dinosaurs (birds), many of which, as you know, have very intricate and interdependant relationships with many flowering plant species.
2007-03-27 13:11:55 · answer #2 · answered by darrenhb69 1 · 0⤊ 0⤋
You would have to define plants better for an appropriate answer. Many scientists consider algae to be plants these evolved long before seaweeds for example. In turn both of these evolved way before terrestrial plants. So your answer depends on your definition of a plant.
2007-03-27 11:07:43 · answer #3 · answered by pathc22 3 · 0⤊ 0⤋
June 4.
just kidding.
The first cells evolved about 3.5 billion years ago. The first photosynthetic organisms, what we could consider plants, evolved about 2.4 billion years ago - meaning that there was 1.1 billion years of just bacteria running around.
Neat, huh?
Read more below:
http://www.yale.edu/ynhti/curriculum/units/1980/5/80.05.01.x.html
2007-03-27 10:17:50 · answer #4 · answered by Brian L 7 · 1⤊ 1⤋
The exact date is unknown, but it was somewhere between 2.7 and 2.4 billion years ago, when the atmosphere was switched from CO2 to oxygen.
2007-03-27 10:16:20 · answer #5 · answered by Anonymous · 0⤊ 1⤋
november 3rd 1979
2007-03-27 10:15:52 · answer #6 · answered by Anonymous · 0⤊ 0⤋
about 5 million years.
2007-03-27 10:26:13 · answer #7 · answered by JOHNNIE B 7 · 0⤊ 1⤋
exact? april 21st, 3,000,000,000,000,000,000 B.C.
2007-03-27 10:39:28 · answer #8 · answered by benscoobert 1 · 0⤊ 0⤋