Discussion»Questions»Environment» Can you think of one thing that was about millions of years ago and are the main reasons why all animal and vegetation became so prolific
I couldn't find a specific explosion of life forms at one million years ago. By then, most of the evolution as we know it now was pretty much in place - except of course for the megafauna which died at the end of the last ice-age. At around 800,000 years ago we finally get modern humans.
The real explosion of life starts about 500 million years ago, after the plankton in the sea had been around long enough to create an atmosphere with sufficient oxygen to allow for the evolution of animals. The evolution of plant life on land assisted in the production of oxygen.
Oxygen is the key factor that makes the explosion of life possible - then the cohesion of RNA and DNA mollecules, and then the evolution of chromozones, genes and sexual reproduction.
millions of years ago
-4500 — earth
–
-4000 — water
–
-3500 — single-celled life
–
-3000 — photosynthesis
–
-2500 — oxygen atmosphere
– oxygen crisis
-2000 — Eukaryotes - organisms consisting of one or more cell or cells containing a nucleus with DNA organised in chromosomes.
-1500 — sexual reproduction (as opposed to autonomous reproduction by cell division)
-500 — Cambrian Era - explosion of multiple life forms and species, arthropods, molluscs and invertebrates
– 250 -- dinosaurs -- mammals -- birds -- flowers -- Quaternary Era -- primates The Quaternary Period divides into two epochs: the Pleistocene (2.588 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today)
0 — the Anthropocene Era - geological evidence of human agency altering geology (carbon and other human-caused pollutants found in the most recently laid down strata of rocks and ice.) and the atmosphere.
The Pleistocene Epoch ran from 2.588 million years ago to 11,700 years before now. By the beginning of the Pleistocene our continents were roughly where they are now (even though all of them are still moving very slowly.) The first mammals begin to appear in the late quaternary period of the Pleistocene. Within the Pleistocene are smaller phases; the Calabrian Era ran from about 1.8 to 0.733 million years before now - so it brackets your 1 million.
-------------------------------------------------------------------------------------------------------------------------------------------- millions of years FamilyHominidaeGreat apes: humans, chimpanzees, gorillas, and orangutans—the hominids
20–15
SubfamilyHomininae
Humans, chimpanzees, and gorillas (the African apes)[1]
14–12
TribeHominini
Includes both Homo, Pan (chimpanzees), but not Gorilla.
10–8
SubtribeHominina
Genus Homo and close human relatives and ancestors after splitting from Pan—the hominins
8–4[2]
(Genus)
Ardipithecus s.l.
(Genus)
AustralopithecusGenusHomo(H. Habilis)
Humans
2.5
(Species)
H. Erectus s.l.
(Species)
H. heidelbergensis s.l.SpeciesHomo sapiensAnatomically modern humans
0.8–0.3[3] All of this is why we should be concerned about the extinction of life due to 6-9ºC global warming. Already the latest climate change conference is asking to settle on 3ºC as the limit of our efforts and aims. This limit is too high to prevent the feedback system from continuing to accelerate.
This post was edited by inky at December 18, 2019 3:01 PM MST
You touched on so many things quite rightly so.....but still there is still one other taken for granted factor... Im sure Sir Richard Attenborough would arise to the chaLangellabge.....lol
I was thinking more of what's still about now and without them ,how all life on land might be just so different...it wasn't about evolution,more how these things helped and still do provide for all species to survive and exist...without them , I think our plane t would be so different..
With the exception of jellyfish, we need another to reproduce. The need for each other? survival of the species? our reproductive organs? the drive to reproduce? water? bacteria? krill? dirt? atoms? eves? ;) This had to follow adams... neutrons? electrical shocks? magnet forces? chemistry? I'm reaching! I give up... What is it?
Please do tell. You're killin' me out here!!
This post was edited by Merlin at December 18, 2019 4:17 PM MST
the Earth, with a tilt in its axis, revolving around a G2 type star sunlight abundant water abundant oxygen and the other gases and elements that support life
Probably the moon's pull of the tides has also had a crucial influence.
As to the meaning of life - I cannot say. I think there is no one meaning of life for everyone. We each look for and create our own meaning, value or purpose for living.
Personally, I can't see any meaning in life whatsoever. Life's instinctive purpose is almost tautological, to survive, thrive, reproduce to perpetuate its kind, and to die. We value life according to how much we enjoy it, and according to how much empathy we feel for other sentient beings' desire to live.
Most awesome answer and thought! So True! It kind of leans toward the direction of Nanoose's thought on the subject. I say this because I've often wondered about our very famous moon and how unique it is in comparison to all the other moons in our galaxy. Please don't get me wrong. I LOVE our moon and the incredible power it has over our planet... and us. It is truly a part of all of us and our world would not be habitable by all the plants, animals, and fish it is today without it. As Nanoose would say, "CHEERS! For The Moon!"
There is no meaning to life ,we can only enjoy it while we can....for so many on this planet ,life is just an every day misery ,finding clean water must be the bane of their lives..
With out mountain ranges there would be far less water across all the continent ,it's the mountains that make the clouds dump billions of tons of fresh salt free water that irrigates all our arable lands and feeds al of our huge rivers world wide.....Plus all the snow that forms on then and returns in time to melt water... Without our mountain ranges ,how much human and animal life would heve servivced
inky 