Register | Sign In


Understanding through Discussion


EvC Forum active members: 65 (9162 total)
4 online now:
Newest Member: popoi
Post Volume: Total: 915,815 Year: 3,072/9,624 Month: 917/1,588 Week: 100/223 Day: 11/17 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   When does microevolution turn into macroevolution?
Neutralmind
Member (Idle past 6123 days)
Posts: 183
From: Finland
Joined: 06-08-2006


Message 1 of 52 (395087)
04-14-2007 9:15 PM


I'm still being confused by the word micro-evolution. Is it really something that can be defined? If you think so please answer these.
What things would one consider micro- and what macroevolution?
* From warm- to coldblooded animal
* Extra internal organs. A new pair of lungs, heart etc.
* Extra external organs. More fingers, eyes etc.
* New internal/external organs. A tail, fin, lungs that previously breath land/underwater now breath underwater/land etc.
* Enhanced abilities. Better hearing, seeing, stamina, resistance for diseases etc.
* If these enhanced abilities now use different mechanisms to work is it macro or microevolution?
Or does micro/macroevolution have more to do with looks?
Also, I want all of you to write more questions because I'm seriously not a specialist in this.
And please, no snardy remarks in the style of "Microevolution is a term used by creos to escape admitting evolution, or macroevolution happens".

Replies to this message:
 Message 2 by AdminQuetzal, posted 04-15-2007 12:23 PM Neutralmind has not replied
 Message 4 by Nuggin, posted 04-15-2007 12:56 PM Neutralmind has not replied
 Message 7 by jar, posted 04-15-2007 2:15 PM Neutralmind has not replied
 Message 12 by Brad McFall, posted 04-15-2007 7:21 PM Neutralmind has not replied
 Message 16 by Taz, posted 04-15-2007 9:59 PM Neutralmind has not replied

  
AdminQuetzal
Inactive Member


Message 2 of 52 (395158)
04-15-2007 12:23 PM
Reply to: Message 1 by Neutralmind
04-14-2007 9:15 PM


Reasonable topic. Promoted to Biological Evolution.

This message is a reply to:
 Message 1 by Neutralmind, posted 04-14-2007 9:15 PM Neutralmind has not replied

  
AdminQuetzal
Inactive Member


Message 3 of 52 (395159)
04-15-2007 12:24 PM


Thread moved here from the Proposed New Topics forum.

  
Nuggin
Member (Idle past 2492 days)
Posts: 2965
From: Los Angeles, CA USA
Joined: 08-09-2005


Message 4 of 52 (395174)
04-15-2007 12:56 PM
Reply to: Message 1 by Neutralmind
04-14-2007 9:15 PM


Micro vs Macro
Gonna try to explain it without a lot of jargon.
Micro-evolution is evolution on a small scale, typically within a species. Think, advancement of one particular trait.
So, here would be an example:
Pre-lawn mowers dandelions all grew very tall so they could get above the grass.
Post-lawn mowers there was a very powerful selective force in favor of short flat dandelions.
The arrival of short flat dandelions is a good example of micro-evolution.
It's micro-evolution because, to the best of my knowledge (Im not a botanist) short dandelions and tall dandelions can still cross breed with each other.
Macro-Evolution is generally considered to occur when enough micro-changes have come up so that the original species and the new adaptation are different enough that they can no longer interbreed.
Using the dandelion example and projecting into the future -- Again, NOT a botanist, just giving examples based on plants and animals we are all familiar with.
Let's say that dandelions typically rely on honey bees for pollination, and that short dandelions, while significantly better at surviving lawn mowers, are not easily spotted by honey bees.
However, short dandelions are easily discovered by bumblebees.
Let's say that the smell the flowers is what attracts one type of bee over another. And for simplicity sake, lets say that bumblebees and honeybees don't like the same smells. (in reality this is a heck of a lot more complex, but I'm boiling everything down to make an example).
Any short dandelions in a yard that are attractive to honey bees will reproduce, but any short dandelions that are attractive to bumblebees stand an even better chance - since the bumblebees can more easily find the flowers than the honey bees.
So, now there is a selective force in favor of flowers which smell good to bumble bees.
Meanwhile, a silimiliar but opposite selective force is in play for tall dandelions making them smell good to honey bees.
As time goes by, short dandelions which smell good to bumble bees out produce their counterparts. And tall dandelions which smell good to honey bees out produce their counterparts.
What we end up with are two kinds of plants, both still very similiar, but with completely different smelling flowers. As a result, the honey bees stick to the tall plants and the bumblebees stick to the short ones.
Because the bees are not carrying pollen from the tall flowers to the short flowers and viceversa, the two types of plants do not (can not) interbreed - they are therefore different species.
That's macro-evolution.
Both are relatively small changes, One just creates the barrier between species.
Now, in mammals, it may require more than one little change to create that barrier, therefore "macro" evolution can refer to an entire host of changes - (ie the numberous small differences which seperate foxes and dogs).
Hope this clears things up a bit.
As for "snardy remarks" - microevolution is easily demonstrated in labs and even the fundamentalists can not deny that it exists. Therefore the reason the two terms are at play is that they accept micro-evolution, but do not believe in macro-evolution.

This message is a reply to:
 Message 1 by Neutralmind, posted 04-14-2007 9:15 PM Neutralmind has not replied

Replies to this message:
 Message 5 by Juraikken, posted 04-15-2007 1:01 PM Nuggin has replied
 Message 17 by Archer Opteryx, posted 04-16-2007 1:07 AM Nuggin has not replied

  
Juraikken
Member (Idle past 6188 days)
Posts: 82
From: Winnetka, CA
Joined: 11-13-2006


Message 5 of 52 (395177)
04-15-2007 1:01 PM
Reply to: Message 4 by Nuggin
04-15-2007 12:56 PM


Re: Micro vs Macro
how would macro-evolution be observed? i understand that the different species in plants would prevent interbreeding, but how can that be observed in teh span of all life?

This message is a reply to:
 Message 4 by Nuggin, posted 04-15-2007 12:56 PM Nuggin has replied

Replies to this message:
 Message 6 by Nuggin, posted 04-15-2007 1:14 PM Juraikken has replied

  
Nuggin
Member (Idle past 2492 days)
Posts: 2965
From: Los Angeles, CA USA
Joined: 08-09-2005


Message 6 of 52 (395184)
04-15-2007 1:14 PM
Reply to: Message 5 by Juraikken
04-15-2007 1:01 PM


Re: Micro vs Macro
I'm a little confused by the term "span of all life".
Do you mean, how can we observe macro-evolution taking place over all of history?
For that we look to the fossil record. As changes mount up, we eventually say - these two are seperate species.
If you look at my dandelion example, you'll note that there would be almost no fossil record for the changes I'm describing - yet macro-evolution is taking place.
In all likelihood, we've overlooked a great number of species splits
We may consider fossils of three very phyiscally similiar birds to be the same species, even though, in practice, their feather coloration (which would not get preserved) prohibits them from interbreeding since the various types of females are simply not attracted to the different types of plummage.

This message is a reply to:
 Message 5 by Juraikken, posted 04-15-2007 1:01 PM Juraikken has replied

Replies to this message:
 Message 8 by ICANT, posted 04-15-2007 3:09 PM Nuggin has replied
 Message 11 by Juraikken, posted 04-15-2007 6:57 PM Nuggin has replied

  
jar
Member (Idle past 394 days)
Posts: 34026
From: Texas!!
Joined: 04-20-2004


Message 7 of 52 (395194)
04-15-2007 2:15 PM
Reply to: Message 1 by Neutralmind
04-14-2007 9:15 PM


history
The whole concept of Macro-evolution is one of history. If we look at a series and select two points that are sufficiently far apart, we may be able to see Macro-Evolution has happened. However, it is far less likely that anyone would ever see Macro-Evolution in adjacent or even relatively close points in the series.
Evolution lineages are like a spectrum.
When we look at the spectrum, there are areas where we can say it is definitely red, or yellow, or green, or blue, or violet, but there are areas in between that are blue-green or orange or kinda redish.
We we look at sections that are close together they are more similar than when we look at sections that are further apart.
Macro-Evolution is nothing more than looking at a selection of critters that are far apart on the historical spectrum we call lineage.

Aslan is not a Tame Lion

This message is a reply to:
 Message 1 by Neutralmind, posted 04-14-2007 9:15 PM Neutralmind has not replied

  
ICANT
Member
Posts: 6769
From: SSC
Joined: 03-12-2007
Member Rating: 1.5


Message 8 of 52 (395202)
04-15-2007 3:09 PM
Reply to: Message 6 by Nuggin
04-15-2007 1:14 PM


Re: Micro vs Macro
Nuggin, I got a couple of real stupid question.
We may consider fossils of three very phyiscally similiar birds to be the same species, even though, in practice, their feather coloration (which would not get preserved) prohibits them from interbreeding since the various types of females are simply not attracted to the different types of plummage.
Does this mean they can't or just refuse to interbreed?
If they just refuse to interbreed why would this be macroevolution?

This message is a reply to:
 Message 6 by Nuggin, posted 04-15-2007 1:14 PM Nuggin has replied

Replies to this message:
 Message 9 by Dr Adequate, posted 04-15-2007 3:23 PM ICANT has not replied
 Message 10 by Nuggin, posted 04-15-2007 3:57 PM ICANT has not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 9 of 52 (395204)
04-15-2007 3:23 PM
Reply to: Message 8 by ICANT
04-15-2007 3:09 PM


Re: Micro vs Macro
Nuggin, I got a couple of real stupid question.
Does this mean they can't or just refuse to interbreed?
If they just refuse to interbreed why would this be macroevolution?
No, it's a good question.
It depends on where you draw the line between species, and drawing lines is tough in biology, 'cos of evolution.
Consider the cichlid fish of Lake Malawi. They are genetically capable of interbreeding, but they don't. And they have vastly differing appearance and habits of life, as you'll see if you follow the link.
Does it make sense to say that they're all the same species?
Edited by Dr Adequate, : No reason given.
Edited by Dr Adequate, : No reason given.

This message is a reply to:
 Message 8 by ICANT, posted 04-15-2007 3:09 PM ICANT has not replied

  
Nuggin
Member (Idle past 2492 days)
Posts: 2965
From: Los Angeles, CA USA
Joined: 08-09-2005


Message 10 of 52 (395205)
04-15-2007 3:57 PM
Reply to: Message 8 by ICANT
04-15-2007 3:09 PM


Re: Micro vs Macro
Dr A gave a good example.
Here's another one. There are many many different "species" of jumping spiders which are, from a mathematical stand point, genetically identical.
However, since these different "species" have different mating dances, even if you put two 99.999% identical spiders together, they can not get in the mood to get it on.
If you were to artificial mix the materials, they could produce offspring, but in the real world, they simply can not.
Hence, since they can not naturally interbreed successfully, they are different species.
Now, keep in mind, we are basically dividing things up using a system we've agreed on to be more organized. Nature is not so organized.
Hence, whales and dolphins are different species (lots of different species) but every once in a while you get a wholphin popping up 'cuz horny is as horny does.

This message is a reply to:
 Message 8 by ICANT, posted 04-15-2007 3:09 PM ICANT has not replied

  
Juraikken
Member (Idle past 6188 days)
Posts: 82
From: Winnetka, CA
Joined: 11-13-2006


Message 11 of 52 (395235)
04-15-2007 6:57 PM
Reply to: Message 6 by Nuggin
04-15-2007 1:14 PM


Re: Micro vs Macro
yes i mean all of history, but when we look at fossils, what makes you think one or the other was related, or even are similar? an African American and a Japanese American look completely different, but when they are dead, their bones are completely the same. what would make you think that one was african american and one was japanese american just by looking at the bones? it cannot.
so then i say this, how can macro-evolution be observed when all we can see are fossils and those are not good enough to prove that to you.
in your dandelion example, i understood all of that taking place and i agree, but look there is an observer. if some person looked at the entire field of short dandelions and had no knowledge of what HAD happened, how in the world would they decide the dandelions were long before? You said there is no fossil record, so how would they know this? you see? your example had an observer, we cannot observe the past because we were not there. my example about an african american and a japanese american is also a way to prove that fossils are a fraction of what that being was.
the bird species, i dont understand how you would know the feather colors when all you see are bones. please explain that more because you guys are making cities out of two small blocks of rock.
Edited by Juraikken, : No reason given.

This message is a reply to:
 Message 6 by Nuggin, posted 04-15-2007 1:14 PM Nuggin has replied

Replies to this message:
 Message 13 by NosyNed, posted 04-15-2007 7:33 PM Juraikken has not replied
 Message 14 by Nuggin, posted 04-15-2007 8:21 PM Juraikken has not replied
 Message 15 by crashfrog, posted 04-15-2007 9:37 PM Juraikken has not replied

  
Brad McFall
Member (Idle past 5032 days)
Posts: 3428
From: Ithaca,NY, USA
Joined: 12-20-2001


Message 12 of 52 (395240)
04-15-2007 7:21 PM
Reply to: Message 1 by Neutralmind
04-14-2007 9:15 PM


I was reading again today:
The Structure of Evolutionary Theory
and it just so happens I noticed exactly how Gould intends the term "macroevolution" to be used. He uses it particularly in reference to his own idea of "isomorphic logic" expecting that linguistic form can not suberate it. The prefix "iso" is associated with the use of isotropic variation at his study on the relatio of De Vries and Darwin but Gould has a far reaching plan for extrapolation from life spans we can recognize in our every days.
Indeed he attempts a practical evolutionary logic construction the likes of HootMan would rather see encrypted but indeed does make the difference between 'macro' and 'micro' one of among or between "species" but he as a peculiar view of Linnaes' plants, no matter the sex, as falling under a GENUS categorically that was reductionistically developed making higher categories artifical human constructs while he wonders if a better study could be made of the genetic holism of Goldschmidt and the ossilation theory of Bateson through which his own isomorphism is supposed to be one-to-one and onto but on a 'whole nother level', not a simple constraint.
Since he agreed to use the schema within Dobshansky's recognition of a need to be "in vouge" with current notions of causality, even if I was to argue that there IS NO isomorphism logically, (I do not think so but if there was then there WOULD be the spectrum of Jar, (this gets more complicated as he recognizes only Goldschmidt's chemically alterable phenocopies and not systemic mutations made into possible molecular facts of Russell as per Woodger statements)), "macro" evolution will continue to dog attempts to pin it down to the lower registers of humanly voiced speech since the history Gould recounted used the words "parental" and "form" as well constiutively, while he has come out against Creationism, unlike me, in a somewhat biased American way.
Creationism has been responsible for plausibly recognizing Kant's difference of immediate and mediate propositions but because the serialization has not been compared genetically and no one has made the comparison Gould suggested historically would be profitable and logicians after Russell have not used propositional functions to the point where the language seperations could shape via relations some incomplete symbol between the two (macro and micro) inhibitions continue to merge the confusions such that neither does the term "meso" evolution work with a position struck nontheless in vogue.
Whatever the form of the difference is, it will be understood better when the role space plays with subspecies in "biological time" has been translated into practice. I am suspicious that Gould's use of "core Darwinian logic" can survive this new century of increased genetic scrutiny.
It may indeed become a case that discussion of "macro evolution" will proceed further under simple presentations of various dissections as you suggested it might look like but it will be a waste of both creationist time and energy and of me not becoming a copy cat evolutionist of our days if the geographic isolation not superfluid be not looked into.
If biologists refuse to stay working on the black line below, it is not my fault.

Click for full size image

This message is a reply to:
 Message 1 by Neutralmind, posted 04-14-2007 9:15 PM Neutralmind has not replied

  
NosyNed
Member
Posts: 8996
From: Canada
Joined: 04-04-2003


Message 13 of 52 (395244)
04-15-2007 7:33 PM
Reply to: Message 11 by Juraikken
04-15-2007 6:57 PM


The fossil record is for macromacro
You miss the point Juraikken. The examples discussed demonstrate why we will see in the fossil record is only divergences that are most often well above the species level.
We see in the fossil record differences develop over time that are clear and if we were categorizing today we'd be at the family or order level because they are big enough to show up in the bones.
However, we can be fooled the other way when there is a wide sexual dimporphism and we might thing male and female are different species.
your example had an observer, we cannot observe the past because we were not there.
A very common misunderstanding this is. We very, very often observe things in the past. "Observing" isn't just looking at something it is also seeing the effects it has (an aside -- we never actually observe a n y t h i n g right now-- we see light from it a tiny bit later than it's 'now' but that is a silly detail).
We "observe" that a building existed of a certain size by finding foundtions under the earth. We can observe a number of things about this building without seeing it standing.
If we see hardened rock of a certain kind and form we "observe" that lava flowed under water.

This message is a reply to:
 Message 11 by Juraikken, posted 04-15-2007 6:57 PM Juraikken has not replied

  
Nuggin
Member (Idle past 2492 days)
Posts: 2965
From: Los Angeles, CA USA
Joined: 08-09-2005


Message 14 of 52 (395260)
04-15-2007 8:21 PM
Reply to: Message 11 by Juraikken
04-15-2007 6:57 PM


Re: Micro vs Macro
A couple of issues with your post --
an African American and a Japanese American look completely different
No, an African American and a turnip look completely different. An African American and a Japanese American look very much alike. If I have a these two guys and a turnip in a line, you would have absolutely no trouble picking out the two humans.
Now, what you can say is something along these lines: There are many characteristics which seperate African Americans from Japanese Americans (skin tone, height, hair placement and style, vocal range, etc.)
But both of these are the people are the same species, and as you correctly pointed out, stripping away everything but the skeleton we'd lose sight of a great number of the so called differences.
I don't see how this is a problem though? They are both human. And, judging from their remains we would concluded correctly that they are both human.
how can macro-evolution be observed when all we can see are fossils and those are not good enough to prove that to you.
I think you misunderstand what I was saying above. I'm not saying that fossil evidence doesn't demonstrate macro-evolution. What I am saying is that macro evolution can occur outside of evidence in the fossil record.
The fossil record, in other words, gives us evidence for macro evolution in and of itself. But the sum total of macro-evolutionary changes that have actually happened are not all recorded in the fossil record.
I'll try to make up an example:
If there is a muddy bank of a river and a bear walks on it it leaves footprints. If that mud then hardens and becomes stone, those footprints are preserved. That is evidence that at some point a bear walked on that spot. However, we can assume that in the past many many things have walked on the spot - it's just that circumstantially, only the bear left footprints.
My pointing out that not all things which walk always leave foot prints does not in anyway lower the evidentiary value of the foot prints we do have.
if some person looked at the entire field of short dandelions and had no knowledge of what HAD happened, how in the world would they decide the dandelions were long before?
If a person only saw short dandelions, you would be correct. however, if an observer came upon a field of short dandelions, noted it, then came upon an area of tall grass and discovered tall dandelions, they would have additional data.
If they saw a lawnmower cut down the tall grass, they'd have even more data.
If they found paintings from a time before the invention of a lawnmower and only saw images of tall dandelions, they'd have even more data.
If they tested the genetics of dandelions living today and of dandelion pollen found in sedament from thousands of years in the past, they'd have even more data.
As they continue to dig deeper, they get more and more information. As they picture fills in, they get a better grasp of what actually happened in the past, even if they were not there to observe it.
Remember, it's not like scientists found one fossilized dino bone and came out the complete field of paleontology as you see it today. Lots and lots of info has been collection, conclusions have been deduced from the facts.
dont understand how you would know the feather colors when all you see are bones.
You wouldn't. Perhaps I wasn't clear enough. My point was this -
Though we do see evidence of macro-evolution in the fossil record, there is undoubtably MORE macro-evolution happening than is recorded in the fossil record.
In other words, it happens, we see it. But sometimes it happens and we don't see it. However, just because we don't have evidence for every time it happens, doesn't mean that the evidence we do have doesn't prove it's existance.
Example -
If you touch something, you leave a fingerprint. If someone dusts for fingerprints a couple days later, they will find some but not all of your fingerprints. They can prove that you were at the location, even if they can't prove how many different things you touched there.

This message is a reply to:
 Message 11 by Juraikken, posted 04-15-2007 6:57 PM Juraikken has not replied

  
crashfrog
Member (Idle past 1466 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 15 of 52 (395280)
04-15-2007 9:37 PM
Reply to: Message 11 by Juraikken
04-15-2007 6:57 PM


Re: Micro vs Macro
an African American and a Japanese American look completely different, but when they are dead, their bones are completely the same.
Actually, that's completely false. Medical examiners regularly discern things like race from completely skeletal remains.
what would make you think that one was african american and one was japanese american just by looking at the bones?
Typically, they consider the length of the long bones, the width of the pelvis, and the structure of the skull to determine race. I'm not a doctor so I can't be more specific.
You really have no idea what a set of bones can tell someone, do you?

This message is a reply to:
 Message 11 by Juraikken, posted 04-15-2007 6:57 PM Juraikken has not replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024