Does the evolutionary tree of plant and animal species point to a single common ancester or could there have been many life creating events?
Seems to me that if conditions were right for the creation of life 3.9Billion + years ago, then why would it have happened just once ?
2007-06-02 11:54:54 · 11 answers · asked by Yeti 3 in Science & Mathematics ➔ Biology
DNA evidence shows quite clearly that all forms of life are part of the same tree. However, we don't have enough evidence to show whether the bottom of the tree is a single root, or more like a bush. We know that very simple forms like bacteria can actually swap DNA, so it could be that we are descendants of multiple progenitors.
So we don't know if it happened just once, or a few times. However what we do know is that once life was established, there was no room for it to happen again - any newly-formed life would immediately have become food for the existing forms.
2007-06-02 21:24:21 · answer #1 · answered by Daniel R 6 · 0⤊ 0⤋
The answer to your first question is "yes" and "yes". Everything living that we know of does point to a single ancestor. But, that doesn't mean there were not other life creating events.
Many things could have happened. Subsequent events could have killed off other life forms. Our ancestral bacteria could have killed off everything else. Or, the other life forms could have been eaten by the ancestral bacteria and absorbed to become part of current life.
2007-06-02 14:02:04 · answer #2 · answered by Joan H 6 · 1⤊ 0⤋
I believe life was brought to Earth in the dust of a comet. And it's all from a single common ancestor. If it can happen here, it can happen on other planets too, if they have the right conditions.
2007-06-02 12:11:14 · answer #3 · answered by Acai 5 · 0⤊ 0⤋
Single common remote ancestor resembling today's prokaryotes. The evolution of anerobic prokaryotes might have been fallowed by evolution of early types photosynthesizers, most probably like todays cyanobacteria like organisms. This might have changed the reducing atmosphere into oxidising atmosphere. Thereafter, formation of aerobic forms of life might have laid the foundation of plant evolution and animal evolution separately.
2007-06-03 01:54:23 · answer #4 · answered by Janu 4 · 0⤊ 0⤋
The evidence is that all life is based around a common DNA ancestor. And no, viruses, some of which only have RNA, are not alive.
2007-06-02 13:44:41 · answer #5 · answered by Anonymous · 0⤊ 0⤋
yes: according to our " Earth's Prehistoric Time we'd has
found several Animal Fossels that dated back towards the
Jurastic Periods basicly found by those Palentologist an team of Scientist in which studies Dinosaurs, Plants, Sea
Mamals remains are now put in Natural History Musem or
La Brea Tar Pits because education teaches us only "
2007-06-02 12:42:13 · answer #6 · answered by toddk57@sbcglobal.net 6 · 0⤊ 1⤋
Life probably started off in more than one type of cell. Only the best adapted survived to give rise to modern life.
2007-06-02 12:00:01 · answer #7 · answered by Anonymous · 2⤊ 0⤋
It all started with hot magma. Then it cooled off and chemical raeactions created organic molecules and water started flowing. Then came single celled organisms and it evolved into different things.
2007-06-02 12:05:57 · answer #8 · answered by AMTRAK 2 · 0⤊ 2⤋
Who's saying it did? (other than religious zealots) There could be life creating events going on all the time. If you saw one, and didn't know what it was, you wouldn't know it was going on ;)
2007-06-02 11:59:52 · answer #9 · answered by Dull Jon 6 · 0⤊ 1⤋
The first fully successful form would have consumed all other attemptors.
2007-06-02 11:58:42 · answer #10 · answered by Anonymous · 1⤊ 0⤋