how fast does evolution happen?Many species seem to become extinct in the short term,how many species emerge?

Question

I am not aware of the recorded emergence of an entirely new species of mammal,fish or other higher organism.If a new species is to emerge,reproduce and become dominant in a few million years,surely we should see frequent evidence of new species emerging within a short time frame of maybe thousands or even hundrerds of years.

fish with legs,aquatic cows with gills, that sort of thing,not tiny changes to morphology.Surely to evolve a whale and a gorilla from the same common ancestor must require significant jumps, not small increments.

Answer 1

The speed of evolution depends on the variability of the species. Highly variable species evolve quickly, while those with low variability evolve slowly.

The "emergence" of a new species is a completely arbitrary decision, because at no point can one say that a given individual is of a different species than its parents. But there are a number of ring species in which the line is so arbitrarily drawn now, one would be hard pressed to say whether it's one species or two.

The observed rate of phenotype change in some Galapagos finches, seen in response to climate change, is between 10,000 and 40,000 times faster than the overall rate of change seen in the vertebrate fossil record. So yes, it can happen quickly.

Answer 2

Divergence takes hundreds to thousands of years depending on generation times. Humans and chimps diverged 4-5 million years ago. A typical movie runs at 24 frames per second, so a two hour movie has 172800 frames. If you divided 4,000,000 years into 172,800 frames, each frame (or generation) would be over 23 years long. Creatures that go extinct are at the end of their divergence. New species are just beginning their divergence. A classic case appeared when apples were introduced into the US Midwest. The hawthorne fly (which feeds on hawthorns) started atacking the apples. Now some prefer apples and some prefer hawthorns. How different are they? Parasitic wasps also have individual preferences for which ones they attack.

Answer 3

It sure does sound as if you already have your answer to your own question. Since you say you are not aware of the recorded emergence..., certainly part of that awareness (if earnest?) would be education. Most puzzling...
Higher organism. Species.
Well, I must say biology has itself to blame (partly) for the confusion. While we are beginning to understand the science of Complexity; we are just started. That means that the term "higher organism" while in widespread use, is founded on our profound (biological) ignorance. A scientific definition of "higher organism" would include concepts from complexity analysis and we are only beginning to understand the context of the questions we should be asking (and answering) to get there.
Part of the problem is that complexity has both "nature" and "nurture" components (which interact). Both DNA and the environment the DNA is expressed in contribute to an organism's complexity. As a basis for science of the 19th and (unfortunately) 20th Century we should have the First Law of Science: "The world fits perfectly into whatever categories we arbitrarily choose". Of course, it doesn't. There are bugs with more DNA than we have (in terms of genes). Are they "higher"?
So, "higher organism" is pretty meaningless (with all due respect to some religious traditions which have informed Western thought on the subject for the last 2000 years). Yet. Maybe someday it will. Maybe even today it does, for some.
Species. When I was younger the definition of "species" was based on reproductive sucess of interbreeding. While a lion and tiger could interbreed, the chance of their doing it successfully is low, hence Lions and Tigers and Bears are all different "species". It is estimated by some that 50% of human conceptions do not result in a sucessful pregnancy. Hence using the same criteria, we are not a species. Strange.
No, actually ridiculous. And, of course wrong. But I bring it up only to suggest that we haven't really gotten our act together on this concept. Species does NOT mean the same thing for a virus as a bacterium, nor for an amoeba and a bird.
Anyway. Here's the question: If my parents are of the same species as me, and their parents, and their parents, etc., etc. HOW could I have evolved from a different species?!! By definition this is a non-sequitur. And yet I accept as most likely the idea that one of my ancestors had four legs and a tail and laid eggs. (With whom - sorry - with which nobody now living would be reproductively fertile). When is a species NOT a species? The problem is in the use of the term "species" to mean so many different things.
So. Here it is (in case you actually want an answer to your question). Species change moment to moment. Every new individual and every death changes the distribution of the genes in the population of that species. (This is not always the case if the genes have little variation, but is true for most sexual species). The change is a result of 1) breeding, 2) survival (or not) , 3) mutation and 4) environment (some documented cases for gene transmission (NOT EXPRESSION) differences due to environment) but this I'll ignore.
At what point have the genes of the population changed enough to justify a claim of a different species? Notice I didn't say "new species" because the question then would become "new" relative to what? Answer: We don't know, but we know it when we see it sometimes (four legs and tail vs two and live birth). Note that not only can genes mutate but some characteristics can increase or decrease in a population (frequency of genes changes in population). We just do not have a clear answer for what "THE" criteria for "evolution of a new (different) species" "IS". So we can't answer the question of "when" except in an paleontological sense ( when we see it). The emergence of a new (different) species requires the existence of a reference population (either real or in some sort of record or database).

The "speed" of emergence is based on 1) reproductive cycle and 2) the environmental "pressure" on the individuals. Mice with many generations possible a year CAN change much faster than elephants with a generation requiring years. But they WILL change only if they are subject to enough pressure to make the current gene distribution much less than optimum (perhaps with beneficial mutations helping some individuals survive and breed) but not too much (which would lead to extinction). Sucessful evolution requires not just reproduction and pressure, but also a population large enough to sucessfully "answer" the pressure. (And of course the "pressure" has to be of sufficient duration to allow the "different" to appear and not be subsumed back into the base population).
Mice highly tolerant to rat poison exist, are they a different species compared to mice with normal tolerance to it?

Incidentially, another way to look at the term "species" is that it is used to communicate broad imprecise generalities, so has a realm of utility, but should not be used when getting into the specifics.

Answer 4

It is a very slow process. Evolution is essentially the gradual change of the gene pool of a given species over time. This is such a simple concept, but so many people have such difficulty with it.
I recently heard that a famed BBC correspondent by the name of Alistaire Cooke had died. He was famous for writing and then reading on the airwaves his "letter from America". He did this every week without fail from 1946 to 2004, or for just over 58 years. I asked my Aunt who was born in 1921 if she thought the country had changed much, if at all, during that time. Her answer was "HEAVENS YES!!!" "It's like no comparison!!". But then I asked her, "how much did it change from week to week?" and she said, "well not by very much, but changes had to be happening, of course".
So I ask you: "How much has our country changed in the last week?" If you can give a good answer to this question, then I think you are well on your way to understanding evolution. If you can't give a good answer to this question, or if you can't see that anything has changed in our country in the last week, then I was wondering if you ever plan to let your black people go free, perhaps in your last will & testament, as is commonly done nowadays? Please let me know.
Actually, to answer your question specifically, the science of Biology has not really been around to any significant level of academia until the mid 19th century, or perhaps 160 years ago. This is clearly too short for a truly new species to emerge, even under ideal circumstances. However, there are several runner ups, if you want to call them that. The most obvious is the "Hawaiian Wallaby" which is descended from a founding population that arrived in Hawaii approximately 250 years ago, and has run wild there ever since. Strangely, or perhaps not so strangely, it bears almost no resemblance to its Australian cousins, since the two groups have been breeding under totally different selection pressures for all this time. Had we not known its history, we would certainly class it as a separate species.
Another example is "MRSA" or "methicillin resistant staphylococcus aureus", a pathogenic bacterial species well known to us MD types. It originally came from staphylococcus aureus, but it is so different now that we could almost consider it to be a different species. Had we not known its history, again, we would have classed it as a separate species, I am certain. I hope this answers your question, at least a little.

Answer 5

i am not positive were the experiment was done and by whom but there was done in the 60 an experiment with rats apparently in the species they used about 5 to 10% of the pop is able to swim for a given period .
the rats were given food and room for a period (i think the number was 300 ) and then the holding pen was flooded the survivors were allowed to breed back up to the number when the first flooding took place so there genetic sample was consistent
in 3 generations they had a population were over 90% of the rats swam i suspect if they had continued the experiment they may have bred a aquatic rat in 300 generations

Answer 6

Fancier: "lots of those so referred to as "lacking hyperlinks" are quite totally type creatures." all of them are. each and every creature that has ever lived and reproduced has been a completely shaped creature. Your want for a 0.5-something 0.5-something else is a results of your lack of awareness approximately how evolution works, and isn't any longer something extra beneficial than a favored creationist straw guy. "lots of those "lacking hyperlinks" have been got here upon only in fragments like basically somewhat a cranium or a tooth and not an entire creature and by some potential scientists got here up with those creatures even however that they had no thought what creature it even replaced into." Which fossils are you referencing especially? What are your problems with the procedures used in comparing them and the conclusions reached? "whilst they chanced on a tooth that they mentioned replaced right into a humanlike creature only it later grew to become out to belong to a pig." And? there have been various faked fossils, which incorporate some that have been speculated to be human ancestors. They have been all found out by utilising assessment with the plethora of authentic human ancestor fossils by utilising scientists, no longer creationists with their hands of their ears screaming that it wasn't authentic.

Answer 7

MRSA - a good example
It's generally accepted that the species, 'Polar bear' is only about 10,000 years old
also, look up Culex molestus - the London Underground Mosquito

Answer 8

Evidently you aren't paying much attention! Look (seriously) again, and you will find the "evidence" you seek. I suspect you don't really want to see the truth.

As the simplest example of evolution in action around you and maybe even in your own lifetime, have you ever taken an antibiotic? Was it penecillin? If it wasn't penecillin, why do you think there was a need for any new antibiotics after the discovery of penecillin?

Think about it!

Answer 9

A "new" antelope was found in south east asia recently. how do we know it is not a new species, rather than one we just hadn't found? Steven J Gould talked about "punctuated" equilibrium, where things remained stable for a long time, then BINGO.

Answer 10

Read Fritjof Capra's 'Web of Live' or 'The Hidden Connections' he puts it together quite nicely and clearly.