|
Register | Sign In |
|
QuickSearch
EvC Forum active members: 64 (9164 total) |
| |
ChatGPT | |
Total: 916,838 Year: 4,095/9,624 Month: 966/974 Week: 293/286 Day: 14/40 Hour: 3/2 |
Thread ▼ Details |
Member (Idle past 2540 days) Posts: 2544 From: boulder, colorado Joined: |
|
Thread Info
|
|
|
Author | Topic: Imported weed diversification supports macro-evolution | |||||||||||||||||||
nator Member (Idle past 2197 days) Posts: 12961 From: Ann Arbor Joined: |
But isn't it OBVIOUS and OBSERVABLE what race the man is in the picture of my post?
|
|||||||||||||||||||
Faith  Suspended Member (Idle past 1472 days) Posts: 35298 From: Nevada, USA Joined: |
Tribes in their tribal territory are usually recognizable. If I wasn't clear, sorry, but how could I have meant anything else? Just as any genetic population may recombine and change its racial character, so can humans.
|
|||||||||||||||||||
DBlevins Member (Idle past 3803 days) Posts: 652 From: Puyallup, WA. Joined: |
But again, here I simply dispute the classification of species in terms of inability to breed. I think that's artificial. Inability to crossbreed is the natural result of enough reduction in genetic potential from a lot of selection pressure or population splits to make for genetic mismatches that prevent successful interbreeding. The result is an overall loss of genetic diversity rather than anything that looks like it could lead to further speciation. Faith, you continue to reinforce the notion that you have no idea what in the world you are takling about. You're saying that we had so much genetic potential 'before the fall(tm)' that everything could breed with anything. Not only that, but now that the fall has gone on for a while, that those pour souless creatures that fail to interbreed because of loss of genetic potential also can not breed with themselves. What an interesting notion...
|
|||||||||||||||||||
Faith  Suspended Member (Idle past 1472 days) Posts: 35298 From: Nevada, USA Joined: |
I have no idea what you are talking about.
|
|||||||||||||||||||
mark24 Member (Idle past 5222 days) Posts: 3857 From: UK Joined: |
Faith,
Where did I say I personally could recognize all the different races and tribes of humanity any more than I could recognize the five different races You said it was OBSERVABLE. It is therefore implicit that you can place people into races by observation. On the one hand you think you can recognise a Norwegian from an Italian, an Arab from a Mongolian, but refuse to place indiginous tribal folk into one of the five major races! THIS is why races are bunk, Faith, because despite "talking about something OBSERVABLE", you are still unable to put tribespeople into racial slots. Mark There are 10 kinds of people in this world; those that understand binary, & those that don't
|
|||||||||||||||||||
Adminnemooseus Administrator Posts: 3976 Joined: |
The topic core theme was 5 species of the goatsbeard plant. No trace of that theme for a long time.
Adminnemooseus This message has been edited by Adminnemooseus, 03-27-2006 04:11 AM New Members should start HERE to get an understanding of what makes great posts.
Comments on moderation procedures (or wish to respond to admin messages)? - Go to:
General discussion of moderation procedures Thread Reopen Requests Considerations of topic promotions from the "Proposed New Topics" forum Other useful links:
Forum Guidelines, Style Guides for EvC, Assistance w/ Forum Formatting, Proposed New (Great Debate) Topics, Official Invitations to Online Chat@EvC |
|||||||||||||||||||
Adminnemooseus Administrator Posts: 3976 Joined: |
Speel-yi, at Thread Reopen Requests:
I would like to comment on this topic as there are some aspects to the original topic I believe I can clarify. Remember, the topic title and theme is "Imported weed diversification supports macro-evolution". Repeating message 1:
In the early 1900s, three plant species native to Europe were brought to america. These three belong to the goatsbeard genus, Tragopogon, and are T. dubius, T. pratensis, and T. porrifolius. These weeds are now common in urban wastelands. In the 1950s, botanists discovered something absolutely amazing. There were two new species in Idaho and eastern Washington. Keep in mind, the original three are also there. The new ones are T. miscellus and T. mirus. Those familiar with the Hardy-Weinberg equation know that it states five conditions that must be met for no evolution to occur. 1) An infinately large population2) No preferential mating 3) No differential migration 4) No mutation 5) No natural selection The goatsbeard is not native to America, but to Europe. It migrated here, even though it had no choice (I don't think many migrations that lead to speciation are truly by choice). Also, the weeds did not migrate back to Europe. The weeds did not have an infinately large population. Because of being placed into a new environment, new pressures would be placed on the weeds. The two new species are also not found in Europe. i don't know about you, but this looks an awful lot like speciation and macro-evolution. Reference: Biology, Sixth Edition. Campbell and Reece (Authors). Published by Benjamin Cummings. Copyright 2002. Adminnemooseus New Members should start HERE to get an understanding of what makes great posts.
Comments on moderation procedures (or wish to respond to admin messages)? - Go to:
General discussion of moderation procedures Thread Reopen Requests Considerations of topic promotions from the "Proposed New Topics" forum Other useful links:
Forum Guidelines, Style Guides for EvC, Assistance w/ Forum Formatting, Proposed New (Great Debate) Topics, Official Invitations to Online Chat@EvC |
|||||||||||||||||||
Speel-yi Inactive Member |
The original Tragopogons were from 2 areas in Europe which never came into contact with eachother. This contact only happened in the Palouse region after immigrants brought them with them to the area, they then then interbred with the other species to produce allopolyploid hybrid offspring. These tetraploid offsping have characteristics that are better suited to the environment here and also produced fertile seeds that continued the line.
A common mistake that is made when discussing these plants is that they mutated from the parent lines...they did not. Rather, the diploid parents gave rise to the tetraploid lines using the existing genetic information. This is an example of sexual reproduction mixing genes in novel combinations. T. mirus for example has purple flowers unlike either of the parents and this is perhaps the most striking difference that can be observed in this new species and the parent lineages. Poloyploidy is one way that plants can produce new species while animals seem unable to produce fertile offspring in this manner. Another commonly seen plant that has appeared recently is the Triticum aestivum which is also a polyploid species.
|
|||||||||||||||||||
subbie Member (Idle past 1282 days) Posts: 3509 Joined: |
Definitional differences are the sign of a paradigm clash. Not accepting the definitions means trying to explain one's different viewpoint but in the end it often does mean that the evo-creo debate simply founders on that issue. Can't be helped. Definitional differences are a sign of a paradigm clash, you are right about that as far as it does. You are completely wrong, however, in implying that it has anything to do with difficulties in this thread. The difficulties in this thread surrounding definitions is due entirely to your, and other creo's, refusal or inability to define "kind." And the only reason it "Can't be helped" is because the term "kind" has no scientific basis. {Edit following Adminnemooseus's chastisement} Oh fer crying out loud. Sorry, didn't read all the way to the bottom, my bad. Carry on and disregard. This message has been edited by subbie, 03-31-2006 03:37 PM Those who would sacrifice an essential liberty for a temporary security will lose both, and deserve neither. -- Benjamin Franklin
|
|||||||||||||||||||
Adminnemooseus Administrator Posts: 3976 Joined: |
I think that all new messages in this topic should be in response to message 53, or to messages that were responses to message 53, etc. In other words, message 53 should now define the theme of the topic.
Or if you must reply to older messages, they should be messages that specifically connect to the content of message 1. Focus on the weed, weedhoppers! Adminnemooseus New Members should start HERE to get an understanding of what makes great posts.
Comments on moderation procedures (or wish to respond to admin messages)? - Go to:
General discussion of moderation procedures Thread Reopen Requests Considerations of topic promotions from the "Proposed New Topics" forum Other useful links:
Forum Guidelines, Style Guides for EvC, Assistance w/ Forum Formatting, Proposed New (Great Debate) Topics, Official Invitations to Online Chat@EvC
|
|||||||||||||||||||
Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
Poloyploidy is one way that plants can produce new species while animals seem unable to produce fertile offspring in this manner. Another commonly seen plant that has appeared recently is the Triticum aestivum which is also a polyploid species. They may not do so as frequently but the evidence would suggest that they can do so, for example many species of Xenopus are characterised by tetra-, octo- or even do-deca- ploidy (Evans, et al., 2004). There is also considerable evidence for whole genome duplication events during the origin of the vertebrate and teleost lineages, such as the duplications of the Hox clusters. TTFN, WK
|
|||||||||||||||||||
Minnemooseus Member Posts: 3945 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: Member Rating: 10.0 |
A little more explanation about the jargon would be nice.
Also, a little more infomation from the cited article would be nice. I shouldn't have to go there to find out that a "species of Xenopus" is an African clawed frog. Moose
|
|||||||||||||||||||
Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
The various levels of ploidy relate to the number of chromosome to a basal chromosome complement (n). A mammalian gamete is usually considered haploid (n), most mammalian cells are diploid (2n) with one copy of each chromosome from each parent.
In the Xenopus family of frogs there are a number of instances of species with 4,8 and 12 times the basal complement of chromosomes:- Tetraploid (4n),Octoploid (8n) and dodecaploid (12n). Xenopus tropicalis for example is diploid while Xenopus laevis is tetraploid, both are common laboratory animal especially in developmental biology. Tropicalis was previously named Silurana tropicalis. The referenced paper used mitochondrial DNA to construct a phylogeny of the various species of Xenopus and tried to determine the number and extent of polyploidy events amongst the species. They estimate that polyplodisation has occurred at least 6 times amongst the species of Xenopus, since the lineages began to diverge. TTFN, WK
|
|||||||||||||||||||
Speel-yi Inactive Member |
I stand corrected. I took my botany classes from one of the researchers on the goatsbeard species. The paper on the clawed frogs came out in 2004 and I guess it's time I got up to speed on this. Thanks...
The Triticum I mentioned is commonly known as "wheat" and it's consumed in large quantities in Western diets. It's also closely tied to the rise of civilization. People eat polyploid organisms all the time and don't know it.
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024