Is there enough time for SPECIATION for million species

[drkfuture]

I wud like to know if speciation really occurs (trans-speciation), Have we had enough time for millions of species? The slow changes in traits in organisms, taking tens of thousands of years to yield a visible change in variation as evolution suggests, does eventually trap yourself in to a problem of "Time Riddle" - you just dont have enormous enough of time at hand for all these species to come into being. A quick average time calculation suggests that you should have a new species come into being every 15-20 yrs [just rough average time estimation suggests that in about 1 billion yrs ~50 million distinct species evolved]. Though I believe in evolution but I cant understand this part.

[SGOS]

If you assume all species traveled the same linear path from a single cell, there might not be enough time, but that's not what happened.  Life's ancestry is a tree that started branching the moment life came into being.  It's not like you had to wait for honey bees, and that apes couldn't appear until after the bees had evolved, and then humans could evolve after the apes.

Time is an orderly linear path where time is a constant, but speciation is a geometric progression that explodes exponentially.  Modern day species didn't come onto the scene one following the other.  Species living today all evolved at the same time.

So you can't count species today and multiply to find an answer that represents anything.  All you get is a number, but it doesn't relate to what you are trying to figure out.

[Hakurei Reimu]

^ Indeed. If there were a speciation event every 50,000 years since 500 million years ago, where every species split in two at each step, there would be ~2 x 10³⁰¹⁰ species today. That's larger than the number of particles in the universe, so the numbers given are quite generous.

Or put another way: yes, a species would have to evolve every 10-20 years, but that's just when it comes off the "evolution belt," as it were. The species actually spent ~50,000 y evolving, but there are many species evolving in parallel, not serially as you are supposing.

Welcome, by the way. You might want to introduce yourself in the Intro subforum.

[Gawdzilla Sama]

Darwin's finches have been observed changing to meet new conditions and breeding true. So it's observable within a few lifetimes at least. There is also the case of stickleback fish being isolated from predators and losing their stickles because they weren't needed. This took less than twenty years according to the study I saw.

Small changes over thousands of years, not millions, can create new species.

AND, if someone claims there wasn't time for speciation you can point out that there are millions of species alive today and there wasn't that many on the Ark, so True Believers have to believe speciation happens extremely fast. ;)

[TomFoolery]

I wud like to know if speciation really occurs (trans-speciation), Have we had enough time for millions of species? The slow changes in traits in organisms, taking tens of thousands of years to yield a visible change in variation as evolution suggests, does eventually trap yourself in to a problem of "Time Riddle" - you just dont have enormous enough of time at hand for all these species to come into being. A quick average time calculation suggests that you should have a new species come into being every 15-20 yrs [just rough average time estimation suggests that in about 1 billion yrs ~50 million distinct species evolved]. Though I believe in evolution but I cant understand this part.

As SGOS pointed out, evolution doesn't typically happen on a linear timeline or in a stepwise fashion as you're imaginging. Punctuated equilibrium offers another path to speciation in which a species remains relatively stable throughout most of its existence and then rapidly evolves and becomes stable again. It's not known if this is the norm or the exception, but it certainly has occurred.

It may help you to consider how and why species evolve and branch off into distinct species. Species don't just speciate as though they are on a schedule: they do it based on conditions that are most advantageous to survival. So while one species may have remained largely unchanged for millions of years, another species may have branched into dozens of distinct species based on any number of factors including genetic drift, sexual selection and mutations.

[Solitary]

We have evolution taking place as we speak, to say it necessarily takes millions of year, is having lacked a thorough education in biology. Why do you think viruses and bacteria have gotten so strong if it isn't because they are evolving? Ever hear of the speckled moth that has evolved since the coal age?

[TomFoolery]

We have evolution taking place as we speak, to say it necessarily takes millions of year, is having lacked a thorough education in biology. Why do you think viruses and bacteria have gotten so strong if it isn't because they are evolving? Ever hear of the speckled moth that has evolved since the coal age?

Well, it's far easier to observe speciation among things with an accelerated reproductive cycle. A virus that replicates itself every minute or even a fruit fly which produces a new viable generation every 2 weeks is a lot easier to keep track of than say, elephants, which take around thirty years to produce offspring that are capable of producing their own offspring.

It would seem like the problem with the original poster's way of thinking is that if fruit flies can speciate in 50 generations in a lab then elephants should also speciate in 50 generations. If you do the hypothetical math, that means it should take fruit flies just under two years to speciate, and if it takes elephants 30 years for each generation then that would mean elephants as we know them today should have emerged 1500 years ago.

The main difference is, yes, you can force speciation among fruit flies in a lab using a founder effect, but those conditions are artificial. Bacteria may even speciate naturally every few years, but competition on a microscopic level is quite fierce. Elephants don't face the same external pressures to speciate based on their dominance within their ecological niche, so they speciate on a far different timeline, which doesn't seem to be all that often.

[Solitary]

I agree. It does take many millions of years to have a species change, but they all still start with mutations of one species. This whole idea that we couldn't have come from Apes is true, however, evolution is not saying that, and if people would actually study evolution and biology they would realize this, and doesn't change a thing about evolution resulting in Homo Sapiens. I keep wondering how long it will take for mankind to evolve beyond superstition and magical thinking. 

[Gawdzilla Sama]

It may take millions of years, but if you compare the Great Dane to the chihuahua you'll find they no longer meet the prime criteria for "same species", they can't reproduce viable offspring. Both animals were bred from wolf stock by humans.

[TomFoolery]

It may take millions of years, but if you compare the Great Dane to the chihuahua you'll find they no longer meet the prime criteria for "same species", they can't reproduce viable offspring. Both animals were bred from wolf stock by humans.

As to whether or not the Great Dane and Chihuahua are different species is kind of a variable answer. Given both are the artificial products of just a few hundred years of some of the most selective and severe inbreeding (and obviously not natural selection) and are certainly incapable of naturally producing viable offspring due to mechanical barriers, they can still artificially create viable offspring with reproductive assistance. They still possess the same number of chromosomes in the same configuration, unlike horses and donkeys for example which can naturally reproduce but have sterile offspring due to differing chromosome numbers.

The ability to hybridize is one way a new species can emerge but naturally it's not that common. Dogs did it with a considerable amount of help from humans.

[SGOS]

As to whether or not the Great Dane and Chihuahua are different species is kind of a variable answer. Given both are the artificial products of just a few hundred years of some of the most selective and severe inbreeding (and obviously not natural selection) and are certainly incapable of naturally producing viable offspring due to mechanical barriers, they can still artificially create viable offspring with reproductive assistance. They still possess the same number of chromosomes in the same configuration, unlike horses and donkeys for example which can naturally reproduce but have sterile offspring due to differing chromosome numbers.

The ability to hybridize is one way a new species can emerge but naturally it's not that common. Dogs did it with a considerable amount of help from humans.

The old timers I've met in Montana say wolves and dogs and coyotes and dogs can still breed.  They even have local names for the outcome, like cyouse.  I don't have any actual knowledge myself, but that's what they say.   Well, SOME have so stated.

[Gawdzilla Sama]

As to whether or not the Great Dane and Chihuahua are different species is kind of a variable answer. Given both are the artificial products of just a few hundred years of some of the most selective and severe inbreeding (and obviously not natural selection) and are certainly incapable of naturally producing viable offspring due to mechanical barriers, they can still artificially create viable offspring with reproductive assistance. They still possess the same number of chromosomes in the same configuration, unlike horses and donkeys for example which can naturally reproduce but have sterile offspring due to differing chromosome numbers.

The ability to hybridize is one way a new species can emerge but naturally it's not that common. Dogs did it with a considerable amount of help from humans.

I'm not the only one noting that GD's and yip-yip dogs have diverged.

[Solitary]

I have a puppy that is half Italian Greyhound and Chihuahua that happened naturally. Also, the breeding of dogs is natural selection because we are part of evolutionary change. We are not separate from nature, and will probably cause the extinction of all life on earth sooner or later because of survival of the fittest with the last breeder praying.

[TomFoolery]

I'm not the only one noting that GD's and yip-yip dogs have diverged.

I know, but it IS debatable, since they diverged artificially and can still reproduce artificially. Chihuahuas and Great Danes almost certainly would have never occurred naturally, and even if they had, wouldn't have done so in less than 200 years with the help of human assholes who prefer breeding dogs to the point of irrelevance.


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[Solitary]

I know, but it IS debatable, since they diverged artificially and can still reproduce artificially. Chihuahuas and Great Danes almost certainly would have never occurred naturally, and even if they had, wouldn't have done so in less than 200 years with the help of human assholes who prefer breeding dogs to the point of irrelevance.


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But because humans are part of the natural world it is naturally. You can't leave humans out of evolutionary change and say it is artificial. The whole world has changed naturally in every way because of humans ever since mankind has been here. Evolution is about change from whatever causes it, we are just one link in that chain. We have pets now because of breeding, work dogs, hunting dogs, and sport dogs. Just because some breeders are just doing it just for money and novelty and don't care about the results doesn't mean they are all like that. My Greyhound Chihuahua mix was from a result of two dogs roaming the streets as strays, and we adopted him from a dog shelter so he wouldn't be euthanized. The mother and father were both saved the same fate by another couple that rescued them. People that have dogs and cats that aren't neutered, are irresponsible jerks who cause untold suffering for innocent dogs and cats, and those that have bred and trained their dogs to bite and be vicious have made Pit Bulls into a pariah to be taken down. I have a very large pit bull next to our house that is the most gentle and loving dog, even more than my mixed breed. My smallest Chihuahua is the most vicious dog I have ever seen, but he can even bite hard enough to hurt even a rat or mouse.