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Need for the term microevolution

by thorium1010
Tags: microevolution, term
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thorium1010
#1
May8-12, 08:37 AM
P: 200
I get somewhat confused when in biology they use the term micro evolution. Is it a standard term in biology? . Because small changes sometimes could result in a entirely new populations. Its becomes quite difficult to distinguish between micro and macroevolution in some cases.

Example take HIV we know that due errors in copying, several different populations or generations of the virus can be present within a single person.

Do we take speciation as macroevolution ?
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mel_c
#2
May26-12, 05:28 PM
P: 7
hi thorium1010,

there is a very simple way to distinguish micro evolution from macro evolution. Just think of this, if the evolution resulted in a new *species*, then this would be termed macroevolution (the debate to whether this really exists or not is a different subject).

If there is no new species (no speciation), then it would be micro evolution. When you refer to different populations or different strains, these are still the same 'species', just different strains or populations of this species.

Hope that helps!
Number Nine
#3
May26-12, 05:57 PM
P: 772
The terms aren't really all that common in biology, and the distinction certainly isn't regarded as being critically important (there is no qualitative difference between the two). The distinction is most commonly made within popular culture, usually in the context of intelligent design, where it has become fashionable to deny that "macroevolution" actually occurs.

ViewsofMars
#4
May27-12, 02:56 AM
P: 463
Need for the term microevolution

Quote Quote by thorium1010 View Post
I get somewhat confused when in biology they use the term micro evolution. Is it a standard term in biology? . Because small changes sometimes could result in a entirely new populations. Its becomes quite difficult to distinguish between micro and macroevolution in some cases.
Macroevolution is evolution on a grand scale — what we see when we look at the over-arching history of life: stability, change, lineages arising, and extinction.”
http://evolution.berkeley.edu/evolibrary/article/evo_47


Microevolution

“House sparrows have adapted to the climate of North America, mosquitoes have evolved in response to global warming, and insects have evolved resistance to our pesticides. These are all examples of microevolution — evolution on a small scale.”
http://evolution.berkeley.edu/evolibrary/article/evo_36

Mechanisms of microevolution
There are a few basic ways in which microevolutionary change happens. Mutation, migration, genetic drift, and natural selection are all processes that can directly affect gene frequencies in a population.
Please read on . . .
http://evolution.berkeley.edu/evolibrary/article/evo_39
thorium1010
#5
May27-12, 11:50 AM
P: 200
Quote Quote by mel_c View Post
If there is no new species (no speciation), then it would be micro evolution. When you refer to different populations or different strains, these are still the same 'species', just different strains or populations of this species.
Thanks, wouldn't that be just the same as adaptation. I Think, that's why it is confusing. I am not a biologist, so i do not know whether they are standard terms used in this field.


Quote Quote by ViewsofMars View Post
Microevolution
“House sparrows have adapted to the climate of North America, mosquitoes have evolved in response to global warming, and insects have evolved resistance to our pesticides. These are all examples of microevolution — evolution on a small scale.”
http://evolution.berkeley.edu/evolibrary/article/evo_36
Thanks for your reply. The examples you give just seems more of adaptation. I thought both adaptation and changes over long time are a part of evolution.
ViewsofMars
#6
May27-12, 12:29 PM
P: 463
Quote Quote by thorium1010 View Post
I am not a biologist, so i do not know whether they are standard terms used in this field.
Hi thorium I'm in bit of a rush today but wanted to tell you that you don't have to be a biologist to learn about evolution. It is taught to children in elementary schools.(1) Thank you for giving me the opportunity to help you by sharing with you the website Understanding Evolution - An introduction to evolution: http://evolution.berkeley.edu/evolib...e/0_0_0/evo_02 . My suggestion is for you to explore it and learn from that website.

Re:Adaptation you can learn about it here:http://evolution.berkeley.edu/evolib...%3A11&x=26&y=4


1. http://evolution.berkeley.edu/evolib...each/index.php
bobze
#7
May27-12, 02:05 PM
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Quote Quote by thorium1010 View Post
I get somewhat confused when in biology they use the term micro evolution. Is it a standard term in biology? . Because small changes sometimes could result in a entirely new populations. Its becomes quite difficult to distinguish between micro and macroevolution in some cases.

Example take HIV we know that due errors in copying, several different populations or generations of the virus can be present within a single person.

Do we take speciation as macroevolution ?

Like #9 pointed out, the terms really aren't that common in biology. They are common in the lay-community, popular press, lay-literature, etc.

They are functionally the same process, just viewed over a different amount of time. How different, really depends on the subjectivity of the speaker--Nothing on nature's part. And that's whats important to understand: they are man-made distinctions, not natural ones.
ViewsofMars
#8
May27-12, 07:11 PM
P: 463
Quote Quote by bobze View Post
Like #9 pointed out, the terms really aren't that common in biology. They are common in the lay-community, popular press, lay-literature, etc.
I'd like to deal strickly with this particular comment you made. The peer-reviewed journal Science does use microevolution:
A Localized Negative Genetic Correlation Constrains Microevolution of Coat Color in Wild Sheep
18 January 2008
Gratten et al., 319 (5861): 318-320

Abstract

The evolutionary changes that occur over a small number of generations in natural populations often run counter to what is expected on the basis of the heritability of traits and the selective forces acting upon them. In Soay sheep, dark coat color is associated with large size, which is heritable and positively correlated with fitness, yet the frequency of dark sheep has decreased. This unexpected microevolutionary trend is explained by genetic linkage between the causal mutation underlying the color polymorphism and quantitative trait loci with antagonistic effects on size and fitness. As a consequence, homozygous dark sheep are large, but have reduced fitness relative to phenotypically indistinguishable dark heterozygotes and light sheep. This result demonstrates the importance of understanding the genetic basis of fitness variation when making predictions about the microevolutionary consequences of selection.
http://www.sciencemag.org/content/31...ce-c56947af587
Furthermore, the link I earlier provided is a valuable resource as well. Thank you.
bobze
#9
May27-12, 09:34 PM
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Quote Quote by ViewsofMars View Post
I'd like to deal strickly with this particular comment you made. The peer-reviewed journal Science does use microevolution:
A Localized Negative Genetic Correlation Constrains Microevolution of Coat Color in Wild Sheep
18 January 2008
Gratten et al., 319 (5861): 318-320



Furthermore, the link I earlier provided is a valuable resource as well. Thank you.
Yes, I am aware that you can search the literature and find the word being used. I'm also aware of UC Berkeley's evo 101 website--Its a great website I often recommend to people. In fact a couple of my friends from undergrad that were fellow evolutionary ecology/organismal biology majors who went to Berkeley for grad school helped work on the site :)

My point was the word doesn't really have a practical meaning to biologists, other then talking about some subjective amount of change that has occurred. If you hang with professional biologists (like I used to do a lot), especially the evolutionary kind--The word really isn't used all that much.

In fact, that is kind of was the whole point of the modern synthetic theory (of evolution)--Are you familiar with it?

The cladists and paleontologists saw what they believed to be "macro" changes in the fossil record. This was periodically explained with different ideas like "hopeful monsters". In fact it ignited a minor war in biology. The geneticists saw local variation occurring (what one might describe as "microevolution") and the two camps fought a little battle about how evolution occurred.

Eventually it was all reconciled by the Fishers, Haldanes, Dobzhanskys and Myars (my favorite). What it really codified was population genetics and showed that the "macroevolution" of the cladists was simply scaled out "microevolution" of the geneticists. Very interesting history, I've thought about writing a book about it, but life leaves me little time for such pursuits :(
atyy
#10
May27-12, 09:51 PM
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P: 8,315
http://www.ncbi.nlm.nih.gov/pubmed/21551350
"Although the macroevolution of V1r and V2r genes has been well characterized throughout vertebrates, especially mammals, little is known about their microevolutionary patterns"

http://www.ncbi.nlm.nih.gov/pubmed/19361692
"Recent studies have begun to take advantage of these attributes and are starting to link the microevolution of horned beetle development to the macroevolution of novel features"

http://www.ncbi.nlm.nih.gov/pubmed/19212402
"Evolutionary biologists have long sought to understand the relationship between microevolution (adaptation), which can be observed both in nature and in the laboratory, and macroevolution (speciation and the origin of the divisions of the taxonomic hierarchy above the species level, and the development of complex organs), which cannot be witnessed because it occurs over intervals that far exceed the human lifespan."

http://www.ncbi.nlm.nih.gov/pubmed/18789136
"Testing whether macroevolution follows microevolution"

http://www.ncbi.nlm.nih.gov/pubmed/11838760
"Several theoretical treatments and empirical reviews confirm previous research in showing that microevolutionary processes are at least capable of generating macroevolutionary trends."

http://www.ncbi.nlm.nih.gov/pubmed/11258393
"The attractiveness of macroevolution reflects the exhaustive documentation of large-scale patterns which reveal a richness to evolution unexplained by microevolution."

http://www.ncbi.nlm.nih.gov/pubmed/3513170
"Microevolution would appear to be accommodated by incremental changes within this fundamental unit, whereas macroevolution would appear to involve "quantum" changes to the next stable size of protein."
ViewsofMars
#11
May27-12, 11:20 PM
P: 463
Quote Quote by bobze View Post
My point was the word doesn't really have a practical meaning to biologists, other then talking about some subjective amount of change that has occurred. If you hang with professional biologists (like I used to do a lot), especially the evolutionary kind--The word really isn't used all that much.

Bobze, I find that hard to accept, considering what I have presented and what atty has also presented. Thanks Atty for the help.

Back in 2004 I recall reading an article from Howard Hughes Medical Institute. Here is an excerpt:

Howard Hughes Medical Institute researchers at Stanford University are closer to understanding one of evolution's biggest questions: How do genetic changes contribute to the generation of new traits in naturally occurring species?

By studying related populations of small fish, called sticklebacks, the scientists have learned how a variety of animals might have lost their hindlimbs during evolution. The researchers discovered that relatively small changes in the regulation of specific genes can lead to a phenomenon called hindlimb reduction. The work demonstrates that rapid skeletal changes can occur in one body structure without disrupting the essential role of the same genes elsewhere in the body.

The research team, led by Howard Hughes Medical Institute investigator David M. Kingsley, published its findings in the April 15, 2004, issue of the journal Nature. Kingsley and his colleagues at the Stanford University School of Medicine collaborated on the studies with researchers from the Fred Hutchinson Cancer Research Center, the Institute of Freshwater Fisheries in Iceland and the University of British Columbia.

“One of the central mysteries of evolutionary biology has been the relationship between microevolution and macroevolution,” wrote Neil H. Shubin and Randall D. Dahn of the University of Chicago in an accompanying perspective article in Nature. “[The researchers] might have discovered a smoking gun—a real example of a type of macroevolutionary change that is produced by genetic differences between populations.”
http://www.hhmi.org/news/kingsley3.html
Bye the way, Dr. Kingsley is also Professor of Developmental Biology at Stanford University School of Medicine. You might enjoy reading his publications from The Kingsley Lab:
http://kingsley.stanford.edu/publications.html

Dr. Kingsley's recent research appeared on April 2012 in the Nature (484, 55-61) publication "Genetics of Evolutionary Change in Vertebrates" : http://www.nature.com/nature/journal...ture10944.html

Also, the prestigious peer-reviewed journal Nature had an article in March 2012 - Heredity 108, 248-255:

Microevolution of sympatry: landscape genetics of hedgehogs Erinaceus europaeus and E. roumanicus in Central Europe

B Bolfíková and P Hulva
Abstract

We used the mitochondrial control region and nuclear microsatellites to assess the distribution patterns, population structure, demography and landscape genetics for the hedgehogs Erinaceus europaeus and Erinaceus roumanicus in a transect of the mid-European zone of sympatry. E. roumanicus was less frequent and restricted to regions with lower altitudes. Demographic analyses suggested recent population growth in this species. A comparison of patterns in the spatial variability of mitochondrial and nuclear DNA indicated less sex-biased dispersal and higher levels of gene flow in E. roumanicus. No evidence of recent hybridisation or introgression was detected. We interpreted these results by comparing with phylogeographic and palaeontological studies as well as with the occurrence of hybridisation in the Russian contact zone. We propose that Central Europe was colonised by E. roumanicus by the beginning of the Neolithic period and that there was a subsequent reinforcement stage as well as the formation of a zone of sympatry after the complete reproductive isolation of both species.
http://www.nature.com/hdy/journal/v1...dy201167a.html
Number Nine
#12
May28-12, 12:39 AM
P: 772
I don't recall anyone claiming that the terms weren't used in biology; the point is that popular culture treats the distinction between the two as a subject of fundamental importance in evolutionary biology, largely due to the influence of creationist lobbying, when biology does't really recognize a qualitative difference between the two. The old talking point about how "scientists have proved microevolution, but not macroevolution!!!1!!1" vastly overstates the importance of the distinction.
ViewsofMars
#13
May28-12, 01:44 AM
P: 463
Quote Quote by Number Nine View Post
I don't recall anyone claiming that the terms weren't used in biology; the point is that popular culture treats the distinction between the two as a subject of fundamental importance in evolutionary biology, largely due to the influence of creationist lobbying, when biology does't really recognize a qualitative difference between the two. The old talking point about how "scientists have proved microevolution, but not macroevolution!!!1!!1" vastly overstates the importance of the distinction.
and

Quote Quote by Number Nine View Post
The terms aren't really all that common in biology, and the distinction certainly isn't regarded as being critically important (there is no qualitative difference between the two). The distinction is most commonly made within popular culture, usually in the context of intelligent design, where it has become fashionable to deny that "macroevolution" actually occurs.
Let's see if I can help you out.Critical Thinking and Scientific Method rids us of
pseudoscientific thinking! Terms are extremely important in science.

Definition of Terminology:
1. the system of terms belonging or peculiar to a science, art, or specialized subject; nomenclature: the terminology of botany.
2. the science of terms, as in particular sciences or arts.
http://dictionary.reference.com/brow...gy?s=t&ld=1029
Reputable scientists aren't in the business of proving science to people. Scientific research
is the way to go.
bobze
#14
May28-12, 07:37 AM
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Quote Quote by ViewsofMars View Post
Bobze, I find that hard to accept, considering what I have presented and what atty has also presented. Thanks Atty for the help.

Back in 2004 I recall reading an article from Howard Hughes Medical Institute. Here is an excerpt:

Bye the way, Dr. Kingsley is also Professor of Developmental Biology at Stanford University School of Medicine. You might enjoy reading his publications from The Kingsley Lab:
http://kingsley.stanford.edu/publications.html

Dr. Kingsley's recent research appeared on April 2012 in the Nature (484, 55-61) publication "Genetics of Evolutionary Change in Vertebrates" : http://www.nature.com/nature/journal...ture10944.html

Also, the prestigious peer-reviewed journal Nature had an article in March 2012 - Heredity 108, 248-255:
VOM, no offense but just googlebing'ing "macroevolution" or "microevolution" in a search engine on pubmed or any scientific journal's website isn't going to give you an idea of how the terms are viewed at current in evolutionary biology. If you want to understand their use and non-use in evolutionary biology you need to sit down and talk with some evolutionary biologists.

I can log on to nature (and I am aware of how prestigious nature is--My name is attached to a couple articles published there) and search for the word "fairy" and pull 1,043 results. Are you going to argue that "fairy" is an integral word used and ruled by science? I hope not. There is a difference in simply searching the literature for words and mining them and actually understanding how they are used in a particular field of science.

Number Nine is spot on again. There isn't a qualitative difference between the two. Again this was settled with the advent of TMS. Arguing that there is two distinct things of "micro" and "macro" evolution only confuses the lay community, plays into creationists hands and really shows that one doesn't understand the processes they are discussing.

There are a lot of good resources echoing what both Number Nine and I have stated. From evolutionary biologists and from professional biologists organizations. For example here is NCSE;

Scientists use the terms macroevolution and microevolution to describe different perspectives on life’s history, not fundamentally different processes. Macroevolution describes the result of evolutionary changes we can observe over time in response to mass extinctions, global climate changes, and other large-scale events that affect the abundance and distribution of species. Macroevolution is what we see in the fossil record as forms of life change from one geological time to another, and we see organisms that share features both with organisms that appeared earlier in time and also with organisms that emerge later. These transitional states show the continuity between groups of organisms even while they demonstrate that changes that occur among them. So, in macroevolution, we focus on patterns of evolutionary changes that occur between species, while in microevolution, we focus on patterns of evolutionary changes that occur within species and evolving lineages. These two terms refer to different perspectives on the process of evolutionary change, but not to fundamentally different processes.
Link


Here is the American Academy for the Advancement of Sciences on the subject;

Macroevolution is not different than microevolution; rather, it is the accumulation of many microevolutionary changes. The definition of what is or is not a species is essentially a human construct. The simplest definition of “species” is a group of organisms that commonly reproduces in the wild. This definition obviously does not apply to asexually reproducing organisms like bacteria. The number of existing species that has been formally discovered is only 1.8 million. It is estimated that there are at least 4 million species, all of which are understood to have descended from one or a few single-celled organisms that were on Earth around 3.8 billion years ago

Link

If you want to actually understand the terms in the context of how biologists actually use them, and don't want to go to the trouble of picking up a degree in evolutionary biology then I'd recommend you read some Jerry Coyne (Why evolution is true). Also I noticed you have a quote above from Neil Shubin--You should actually read his book (Your inner fish) as well, it further supports what both Number Nine and myself have pointed out.

If you are having trouble understanding how the terms are commonly mixed up in the public sphere enjoy this video which points out how creationist misuse the words with intent to prey upon the layman of evolutionary biology;

bobze
#15
May28-12, 07:45 AM
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For Thorium, if you are interested in a more in depth discussion of the terms Talkorigins has a good FAQ page on the history of "macroevolution"

Excerpt:

Ways in which the term "macroevolution" is used by scientists. Some are exact in the way they use it, while others are less exact. These usages are not all the same, and this causes some confusion. Why do scientists not agree on the meaning of their terms?

The meaning modern authors give to the terms "macroevolution" and "microevolution" is often confusing, and varies according to what it is they are discussing. This is particularly the case when "large-scale" evolutionary processes are being discussed. For example, R. L. Carroll, in his undergraduate textbook (1997: 10) defines microevolution as "involving phenomena at the level of populations and species" and macroevolution as "evolutionary patterns expressed over millions and hundreds of millions of years". Eldredge says, "Macroevolution, however it is precisely defined, always connotes "large-scale evolutionary change" (1989: vii) and throughout his book speaks of macroevolution as roughly equivalent to the evolution of taxa that are of a higher rank than species, such as genera, orders, families and the like. In his book Evolution, Mark Ridley defines the terms thus (2004: 227):

Macroevolution means evolution on the grand scale, and it is mainly studied in the fossil record. It is contrasted with microevolution, the study of evolution over short time periods, such as that of a human lifetime or less. Microevolution therefore refers to changes in gene frequency within a population .... Macroevolutionary events events are much more likely to take millions of years. Macroevolution refers to things like the trends in horse evolution ... or the origin of major groups, or mass extinctions, or the Cambrian explosion .... Speciation is the traditional dividing line between micro- and macroevolution.

There are many papers published that use the term in this "higher category" way; why is that?

Science is not always consistent in its use of terms; this is the source of much confusion. Sometimes this is carelessness, and sometimes this is because of the way in which terms are developed over time. When biologists and paleontologists talk about macroevolution in the sense of "large-scale" evolution, they are strictly speaking meaning only a part of the phenomena the term covers, but it is the most interesting part for those specialists. That is, they are talking about the patterns of well-above-species-level evolution (Smith 1994).
Link
Evo
#16
May28-12, 09:57 AM
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Thank you bobze, wonderful explanation. I am closing this now as the OP's question has been answered and to prevent more confusion.


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