Is there evidence for macroevolution?

Hey All,I was wondering, do we have real concrete evidence for macroevolution? If so, what?Microevolution is certainly seen all the time. And microevolution is propelled by Natural Selection-- is it not? Is Natural selection the same process that instigates the emergence of new species? That is, an organism that is so adapted that it can't be recognized by the limitations of it's physical "species definition"? For example: the translation of our common ancestor to modern homo sapiens sapiens (modern man).As far as I understand that is the gist of how macroevolution works, however, what are the evidences for this process? Your answer can be in any field.-Sean

Thread moved here from the Proposed New Topics forum, after making the title more descriptive.Reminder to any contributors. One of the forum guidelines is that we do not respond with bare links, or with huge quoted extracts from other sources. You may reference material, but please also give some summary or descriptive comment to go with it.AdminSylas[This message has been edited AdminSylas, 05-03-2004]

I think there's a number of misunderstandings involved with your post. No. Speciation - the emergence of new species - is caused by reproductive isolation. That's a situation where part of a population is cut off from the rest, and genetic change accrues (as a result of the interrupted gene flow) to the point that the two populations cease to be interfertile. I'm not sure that you have the right idea about what a species is.A species isn't defined along physical parameters. A species is simply a reproductive community - it's a population whose members can and do interbreed. In other words it's a gene pool.So there is no "physical species definition", because that's not what species means.Now, are you asking if we have proof that speciation happens? Yes - there's a number of speciation events recorded in the wild and in the lab.Also, are you asking if speciation ever leads to new populations dramatically different than their forbearers? Yes, and here's my favorite example:

quote:

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Coloniality in Chlorella vulgaris

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Boraas (1983) reported the induction of multicellularity in a strain of Chlorella pyrenoidosa (since reclassified as C. vulgaris) by predation. He was growing the unicellular green alga in the first stage of a two stage continuous culture system as for food for a flagellate predator, Ochromonas sp., that was growing in the second stage. Due to the failure of a pump, flagellates washed back into the first stage. Within five days a colonial form of the Chlorella appeared. It rapidly came to dominate the culture. The colony size ranged from 4 cells to 32 cells. Eventually it stabilized at 8 cells. This colonial form has persisted in culture for about a decade. The new form has been keyed out using a number of algal taxonomic keys. They key out now as being in the genus Coelosphaerium, which is in a different family from Chlorella.

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For one thing, I'm not convinced that macroevolution is any different than microevolution, no more than walking to the store is fundamentally different that walking ten miles. Moreover what you refer to as "macroevolution", which appears to be speciation, isn't a process, it's a result. Specifically it's the result of allele frequency change happening in a situtation of reproductive isolation (and that allele frequency change is the result of random mutation and natural selection.)[This message has been edited crashfrog, 05-03-2004]

Hi,I found a link written in 2000 about two different species of Salmon evolving from one in 60-70 years (13 generations). Look at this link: No webpage found at provided URL: http://news.bbc.co.uk/1/hi/sci/tech/979950.stm.SkepticScand

What is macroevolution? How do you define it?I've never seen macroevolution used as a term in mainstream biology texts, it only ever seems to occur in Creationist literature with a de facto definition of 'whatever cannot be proven beyond unreasonable doubt'. Although I do believe it was originally used by evolutionist, but the original meaning was rather different.[This message has been edited Mr Jack, 05-04-2004]

Macroevolution is a scientific term and is commonly found in textbooks on general biology and on evolution. I think a relevant definition would be that used by Francis Futuyma in the Third edition of his classic 'Evolutionary Biology'. Unforunately the vagueness is one of the key features of Macroevolution. A broad cross section from the various biology and evolution textbooks I mentioned earlier would probably throe up a number of different definitions which may well be broadly in agreement but are unlikely to all be the same.For further evidence of the continuing use of macroevolution in current evolutionary research just do a search on pubmed for macroevolution, a comparison with just evolution will show just how much less work has been done which specifically sets out to address macroevolution.TTFN,WK

Skeptic, your link simply says the two groups of fish prefer not to interbreed. According to Crashfrog's explanation of what makes a new species, there is no new species until it becomes impossible for the two groups to interbreed. It looks like the 70 year event is simply miroevolution.Would it be correct to say that microevolution does not become macro until interbreeding becomes impossible between two of a species?

Clearly I'm reading the wrong books. Has it come into usage recently? My collection is second hand, and somewhat old.

Like hawthorn maggots and apple maggots, who breed at different times of the year in the Pacific Northwest?
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Dogs and wolves are allegedly separate species yet can interbreed and produce fertile offspring.Talk Origins says that macro is change at or above the species level. However Creationists since the time of Linne knew that speciation occurred. IOW for over 200 years Creationists have known that the Created Kind was above the species level.

But it remains, does it not, that both magots are still capable of interbreeding? Is this not just micro stuff affected by the environment and which could be reversed under the proper conditions? How many times over the ages do species do the micro thing back and forth and adjust every whichy way as the environment changes?

Dogs and wolves are not seperate species according to the biological species concept.

I understand what you are saying, and this salmon-example may just be microevolution, but it surely indicates how one specie can start on the path of macroevolution. I'm not sure how to tell when macroevolution would occur in an evolutionary lineage, but I know that you can interbreed two animals with an anscestor quite far back, like i.e. a goat and a sheep, named 'geep'. I'm not sure if the genetic difference between a goat and a sheep is that different from i.e. a human and a chimp (98% similar).Regards,
SkepticScand[This message has been edited SkepticScand, 05-04-2004]

In the sense that we use the term, creationsists didn't exist 200 years ago. They were the mainstream scientists of the time then.Do you have any citations from the first half of the 20th century for this? That might be hard to find since that wouldn't be on the web so if you can't we'll just put it aside.It seems that the current creationist organizations still haven't figured out where "kind" is. In that case how can you say just what level it is at? Do you have a site that gives the current creationist definition of kind? Will you be surprised to find that creationsist sources that have been quoted here have differing definitions.Since "kind" is still undefined it isn't valid to make any claims as to what it is or is not.

I was going to say that they are still given a separate species name anyway. Wrong!They are Canis lupus familiaris. Just don't get to 'familiar' with the other Canis lupus!