Another Question On Evolution?

Question

Ok, if life started from some gene or fungi, my question is, for all the extint animals, will they ever come back?????????

if so why haven't dinosaurs returned??????????

answer my other evolution question

http://uk.answers.yahoo.com/question/index?qid=20070811005558AAwAPyu&pa=FYd1D2bwHTHwLLxuFeIyRLx4iJmHEaUR8IuBNt9gDOINAw--&paid=asked&msgr_status=

DO REMEMBER THE STARS

bad guppy- NO ONE HAS :(

Answer 1

The only problem with asking this sort of question is the period over which you make your observations.

Perhaps in the next few billion years they will, but will there be anyone around to see them.

Answer 2

First of all it is presumed that the first life form was a bacterium, and that life started about 3.7/3.8 billion years ago. Since then, apparently, we have evolved.

As you know, some creatures have evolved and become extinct, they failed to adapt and survive. Those that have adapted and survived are still with us today, though altered. This may sound like a dumb woman's answer, but this is an essay question for which there is no absolute definitive answer, and I've got a cheesecake in the oven that needs to come out in three minutes.

Those creatures that have adapted and survived can still adapt/evolve as the conditions in which they live in change. Evolving requires changes in the DNA which can happen by addition, deletion or substitution of the genome, which are often caused by mistakes in transcription, many well-known and inheritable diseases have arisen this way. However, as well as diseases, there have also been beneficial changes that allow a creature to adapt and survive, even though the mutation in the genome is random. Those that survive, are more likely to reproduce and so the new gene lives on.

In the case of dinosaurs, although we're not entirely sure what wiped them out, they failed to evolve and adapt to whatever new condition was present in the environment, so they died out. Their genes are no longer present in our gene pool. However it is possible for any creature on this planet to evolve genes either similar or identical to those of the dinosaurs, but, as the rules of Natural Selection state, unless the evolved gene is beneficial and helps the creature to adapt and become better suited to its environment and therefore reproduce more than others, this gene could easily disappear once more due to lack of numbers.

Also it may take several million/a couple of billion years to re-evolve the dinosaurs. They don't just appear out of nowhere. They only disappeared 65 million years ago, so you'll be well and truly dead before/if they reappear again.

So basically, if life continues to evolve, if the right mutations occur, if the mutations are beneficial, if the mutated organisms are better adapted to survive and reproduce, then that organism will appear. But please bear in mind, not all mutations are beneficial, mutations are random, it may take many generations for a mutation to occur, and that mutation need not alter anything drastically if at all. So if the dinosaurs do just so happen to reappear, we're either not going to be around, or else we'll have evolved into something very different.

Answer 3

The extinct animals won't be back because they heard there were creationists about and they did not wish to share a planet with really, really stupid people. So they all retired behind the remains of Noah's ark and topped themselves with cyanide laced Kool-Aid. Now if we can only find that mythical boat on that mythical mountain we'd have all the transitional forms that Kent Hovind needs. And he still would not admit he was satisfied.
What is the difference between a gene and fungi? Do you know? Do you care? Or are you pulling legs?

Answer 4

Aaah but folks - are we forgetting some "dinosaurs" have "returned"? Take the Coelocanth for example - considered extinct for 20 million years, we now know it is swimming in the Indian Ocean today. There have been numerous sightings of the Thylacine (Tasmanian Wolf) over the past 30 years or so since it was declared extinct although I will concede unlike the coelocanth this is not a reconfirmed species. If you look at this month's Fortean Times and its cryptozoology section, you will see that this year alone, many new mammals have been found - last year they even discovered a new species of elephant hidden deep within the jungle somewhere! Modern science has only been around 400 years or so, so who knows what still has to be discovered out there on our great big planet. (That's why we have to look after it, folks!)

So, whilst it is technically improbable (nothing is impossible within the realms of science) that evolution cant go backwards, who can prove that the coelocanth isnt a re-evolutionary throwback? After all, human children are born with tails aren't they?

Nessie

*I apologise if I am ruffling any feathers today - its my birthday and Im feeling a little contentious! I have the devil in me today! ;o)

Answer 5

Life evolves to fit a gap in the food chain. There isn't on big enough to support the potential return if the dinosaur. If some cataclysmic event hit the planet and drove life back to the position the planet was in when the had previously evolved (this has happened on several occasions throughout the past 250million years) there is a good chance they would be back.

Answer 6

Nope. Extinction is forever.

It is *remotely* possible that a new species may evolve that is very similar to another species that is extinct ... but this is very unlikely ... it would require a very similar ancestor species as a starting point + an identical environment + the same exact mutations appearing at just the right times in that evolution (*extremely* unlikely).

And even then, there is no guarantee that the same evolutionary events would produce the same result. (E.g. if a predator snatches some new offspring with exactly the right mutation, before it has the chance to grow up and reproduce, then that's the end of that mutation.)

And even if the result looked *exactly*, it would not be the *same species*, but a very similar species.

Answer 7

There is no guarantee either way that they will / wont / couldn't / wouldn't.

If life were made extinct and everything started again dinosaurs could well make a come back or something similar. It's all a matter of variables.

What you've got to remember about evolution is the time scale... you wont be around to see it and that's for sure..

Answer 8

Extinct is extinct. The chances of another reptile developing into a class of giant carnivores is remote. Their becoming dinosaur-like in appearance is even more remote. The process of evolution is not directed, so the same pathway is unlikely to recur.

Answer 9

*sigh*

Adaptive Radiation is a form of divergent evolution - the formation of each species is dependant on natural selection for survival and continuation.
Keep in mind that ecological niches do not stay the same forever, and in order to survive or live in them - you need adaptations that will allow this. Natural selection plays upon the biodiversity of species, those who are better suited for an environment get to survive and pass on its own traits through reproduction.
According to the theory of punctual equilibrium, evolution occurs through period of rapid 'changes' through speciation and then go through phases of stasis. Stasis occurs because the environment is stable, and change occurs whenever needed to in order to survive (eg: look at Bacteria and Penicillin. Bacteria became resistant to penicillin - once this occurred, you could not with the new 'form' of bacteria bring back the previous form).

Why will prehistoric creatures not return today? Because Evolution evolves genetics too - genetic variations, sequences and number of chromosomes - once changed are not able to naturally return. (eg, look at the example of bacteria above).

Dinosaurs will not return because the environment NOW is not the same as it was back then, the climate was different, and the resources of food too. Bring back a T-rex today, and what will you feed it? Bring back a Triceratops and how will you know what food it ate? Are you able to analyze and find this out through fossilized droppings? Don't think so! (The same applies to creatures such as the Wooly mammoth and Saber tooth).

Face it, you can't bring most of these creatures back to life. The environment has changed, the things they ate may not be around today (or have evolved themselves), and the climate is different too. Something’s are better off left dead if Natural selection acted on and against them. If you can't adapt to your environment, then you're going to die.

Answer 10

The genetic information for any living organism has evolved from its ancestors over millions of years and became extinct due to either climatic changes and therefore reduction in its habitat or from an outside influence like a mass extinction from the theorised meteor impact....for them to reappear as a living personification of its long dead ancestors it would take millions of years and we would not see the evolvement of it....as the life forms that inhabit the present day earth have found niches they can exploit the extinct animals would find it very hard to compete.....life is evolving,,not recycling itself..

Answer 11

each species is unique. genomes contain the potential for an almost infinite number of species, only a small fraction of those have ever lived and only a small fraction of those are alive right now. the chances of evolution arriving back at an extinct species are so low it would probably never happen in a trillion years.

imagine taking a random walk in one dimension. every step, you can go left or right. eventually there's a fair chance you might end up where you started. now consider a random walk in two dimensions. each step you can go left or right AND forward or backward. the chance of ending up back where you started is somewhat lower than for a one dimensional random walk. well evolution is somewhat like a random walk in several thousand dimensions. you almost never end up where you started.