Where does everyone stand in regards to...

[ktulu]

Quote[/b] (Amateur_Expert @ Jan. 22 2005,5:49)]Do you guys think that humans are still evolving?

I personally think that humans have, if not totally halted, slowed almost to a stop when it comes to evolution. The factors necessary for evolution (sexual and natural selection) don't affect humans anymore.

We don't adapt to our sorrounding we make them adapt to us. And when it comes to choosing a mate, theres virtually a person for everyone.

how can you say that sexual selection does not affect humans, atleast in this culture and in many western cultures. We SELECT our own mates, we date them we go through this rigorous mating ritual to see if they are the person that we want to mate with. Also if after sometime we decided we dont like that mate we go and find a new one. Also our ability to control reproduction also plays a factor since often times people will be with other "mates" for reasons other than sexual reproduction.

although i will agree most, but not all, "natural" selection has been removed and been replaced with human created artifical selection. by artificial i mean the ability to deal with new industrial biproducts that are harmful to humans. some people can deal with dangerous chemicals enter the body in small doses without minimal effect on their reproductive capabilities, while other will become unable to reproduce or have weak offspring. although the results of this is something that is not yet know it is an area of new study that many bioanthropologists are exploring. and there is still some natural selection taking place with the example of viruses and bacteria that are not treatable yet some people seem to resist the diseases while other succomb quickly.

 

[TheAlphaWolf]

Quote[/b] ]well you keep harping on the "fact" that speciation has been "observed" yet i have seen not a single strong case of speciation.

Because you don't want to accept them. The goatsbeard was a great example. some species were introduced, so you know that there weren't any other goatsbeard species here besides the ones you introduced, and then you find new species that looked like hybrids but could interbreed and not breed with the old species. They became different species, so it's speciation.

Quote[/b] ]you also like to keep bringing up the fossil record but i ask you this, how can you tell what could interbreed with what when all you have is fossils?

there are many intermediates. While you might not know exactly when one or the other begins or ends, You do know that a modern human could not interbreed with certain other hominids (i don't know the names) because they're way too different.

Quote[/b] ]im not saying evolution is wrong im just saying that you need to accept and adress the weaknesses in it

A weakness would be something that either disproves evolution or is not expected to happen that way according to evolution. Fossils are fossils. You can't expect to know exactly where one species begins and ends because you can't make fossils mate!

Quote[/b] ]where Micro Evolution presumes Species 1 can evolve into Species 1.1, 1.2, 1.3

where species one can evolve into SUBSPECIES 1.1, etc.

Quote[/b] ]while Macro Evolution is dismissed as an unprovable hypothesis (it has not been observed, we have not been around long enough TO observe it.)

speciation is macro-evolution. some may be refering to watching fish become cows but if that's why you don't believe in macro-evolution then that's just crazy because you're asking for impossible proof.

Quote[/b] ]God gave us the earth, lock, stock, and barrel, to do with as we pleased.

I also very strongly disagree with that... another check to my "why not to believe the bible" list.

Quote[/b] ]The world is ours, evolution is probably a natural part of it, and away we go.

whoa.... is that you bugweed?

Quote[/b] ]The factors necessary for evolution (sexual and natural selection) don't affect humans anymore

I think humans are evolving just very, very, very slowly.

Quote[/b] ]while nobody who claims to be of scientific mind can blindly accept macroevolution without making themselves about as "guilty" of faith in the unproven than the religious person they often denounce.

AAAAAAHHHHHH!!! why does everyone keep saying it requires faith? it does NOT require faith! Just like ... EP? said, today's species only make up about 99% of the species that have ever lived in this world.(has anyone answered his question first answer his question!) so it's illogical to think that all the species that ever lived have been here at one point in time.

Quote[/b] ]Asthma, excema, allergies, myopia, etc: all "diseases" made survivable by our modern sophistication.

those things (well... asthma and allergies... I don't know what the other two are) can be caused by the environment (living a super-clean life and not going out there and getting dirty) and not genetics... aldough genetics can play a part... so it could be that you could have survived just fine. who knows?

Quote[/b] ]although i will agree most, but not all, "natural" selection has been removed and been replaced with human created artifical selection

as long as there are things outside of or control (in nature) there will be natural selection. (the earth's magnetic field has decreased about 10 percent... because it may be flipping, so that may root out individuals that are too prone to cancer)
and speaking of sex, AIDS could be something that can help root out people who have many partners. (yes... it does have to do something with genetics... I'll try to find the article later)

 

[TheAlphaWolf]

microevolution-

Quote[/b] ]Microevolution refers to small-scale changes in gene frequencies in a population over the course of a few generations. These changes may be due to a number of processes: mutation, gene flow, genetic drift, as well as natural selection. Population genetics is the branch of biology that provides the mathematical structure for the study of the process of microevolution.

macroevolution-

Quote[/b] ]Macroevolution refers to large-scale changes in gene-frequencies in a population over a long period of time, and is usually taken to refer to events that result in speciation, the evolution of a new species. While microevolution has been demonstrated in the laboratory to the satisfaction of most observers, macroevolution has to be inferred from the fossil record, the traits of extant organisms, and comparisons of molecular evidence (DNA). Its precise mechanisms are an active topic of discussion amongst scientists

in short... microevolution- changes within a species
macroevolution- one species to another species.

 

[TheAlphaWolf]

Quote[/b] ]In studying the brain chemistry of the two mammals, researchers found that when the monogamous prairie vole mates, the pleasure hormone dopamine is released in its brain. The receptors for that dopamine are located in the brain's pleasure center, which also happens to be where the receptors for the hormone vasopressin are located. And vasopressin is linked to social learning.

"They recognize that this good feeling is associated with that particular female," says Larry Young, a psychiatry professor at Emory University in Atlanta.

In contrast, the dopamine and vasopressin receptors are not located together in the promiscuous meadow vole. So when they mate, "they don't make that specific connection to a specific female, they just think that mating feels good," he says.

When Young and his team took the prairie vole vasopressin receptor gene and injected it into the pleasure center of a meadow vole, the meadow vole suddenly preferred just one partner.

Scientists can't see the receptors in humans yet. But it seems likely, says Young, that this gene is somehow linked to human's ability to form social bonds with others. Other studies have found links between variations in the gene and autism.

of course... vole brains are easier to study because they're "lower" animals and you can make them suffer and experiment with them because we were put here to rule over them..
http://www.usatoday.com/news/science/2004-06-16-voles-usat_x.htm

 

[Amateur_Expert]

Quote[/b] ]how can you say that sexual selection does not affect humans, atleast in this culture and in many western cultures. We SELECT our own mates, we date them we go through this rigorous mating ritual to see if they are the person that we want to mate with. Also if after sometime we decided we dont like that mate we go and find a new one. Also our ability to control reproduction also plays a factor since often times people will be with other "mates" for reasons other than sexual reproduction.

Sexual selection is judging our mates on certain parameters before-hand. Girls the world over don't go for just one type of guy and don't have one demand from men. There is a guy for every girl out there.

For example, mating rituals by some birds to show how fit the male is, is a form of sexual selection.

Of course we pick our mates, but that's not the point of sexual selection.

 

[Amateur_Expert]

Quote[/b] (D muscipula @ Jan. 22 2005,12:33)]I would actually go a step further and say we are devolving as a species. Almost all natural selection has been removed, both by science and by legislation. In many ways, "political correctness" is little more than the sophisticates' dictate that a person's capabilities and performance should not affect their opportunities, which seems to me to be the fast track to retrogression, both genetic and civilizational.

I've never heard of de-evolution. I don't think its possible. Maybe we are evolving toward a worse state but evolution isn't a process thats reverse, it's built upon.

 

[ktulu]

Quote[/b] (TheAlphaWolf @ Jan. 22 2005,8:22)]

Quote[/b] ]well you keep harping on the "fact" that speciation has been "observed" yet i have seen not a single strong case of speciation.

Because you don't want to accept them. The goatsbeard was a great example. some species were introduced, so you know that there weren't any other goatsbeard species here besides the ones you introduced, and then you find new species that looked like hybrids but could interbreed and not breed with the old species. They became different species, so it's speciation.

Quote[/b] ]you also like to keep bringing up the fossil record but i ask you this, how can you tell what could interbreed with what when all you have is fossils?

there are many intermediates. While you might not know exactly when one or the other begins or ends, You do know that a modern human could not interbreed with certain other hominids (i don't know the names) because they're way too different.

Quote[/b] ]im not saying evolution is wrong im just saying that you need to accept and adress the weaknesses in it

A weakness would be something that either disproves evolution or is not expected to happen that way according to evolution. Fossils are fossils. You can't expect to know exactly where one species begins and ends because you can't make fossils mate!

Quote[/b] ]although i will agree most, but not all, "natural" selection has been removed and been replaced with human created artifical selection

as long as there are things outside of or control (in nature) there will be natural selection. (the earth's magnetic field has decreased about 10 percent... because it may be flipping, so that may root out individuals that are too prone to cancer)
and speaking of sex, AIDS could be something that can help root out people who have many partners. (yes... it does have to do something with genetics... I'll try to find the article later)

its not that im unwilling to accept your examples of speciation, its that i find that they do not come with enough evidence to convince me that they ahve happened, and even if your goatsbeard is a good example, ok thats one, sorry but clinging to one thing is not good science.

You dont know that those fossils couldnt mate, granted they have many morphological differences, but morphology is not proof of gentic change, maybe we just have the anamolies presereved, maybe humans were much more variable than they are today, we dont know.

"you can't make fossils mate!" exactly

and i said most because i know there are things that are out of our control, and yes AIDS/HIV is a good example of a natural selection that is working on humans, i dont have the article anymore but it seems that individuals in some african populations that have been exposed to AIDS/HIV virus for some time are beggining to develop a resistance to contracting the disease and also have a much longer life span after they have contracted it. also their offspring seem to share the resistance suggesting its gentic, which would mean natural selection would likely make the genotypes that have the resistance more common, though its too early to get acturate measures of it.

 

[ktulu]

Quote[/b] (Amateur_Expert @ Jan. 22 2005,8:49)]

Quote[/b] (D muscipula @ Jan. 22 2005,12:33)]I would actually go a step further and say we are devolving as a species.  Almost all natural selection has been removed, both by science and by legislation.  In many ways, "political correctness" is little more than the sophisticates' dictate that a person's capabilities and performance should not affect their opportunities, which seems to me to be the fast track to retrogression, both genetic and civilizational.

I've never heard of de-evolution. I don't think its possible. Maybe we are evolving toward a worse state but evolution isn't a process thats reverse, it's built upon.

evolution is based on selection of gene mutations, which can be helpful or harmful. also the "fitness" of differnt geneotypes is based on the enviroment, so what maybe benifical to humans hunting and gathering on the plains may not be helpful, or may verywell be harmfull in a industrialized urban setting.

also A_E, there are certain features that are universally considered attractive by all humans, like body ratios in females, or access to resource in males, health is a very big one, and there are a bunch of other i cant remember right now(where is that cultural anthro book) now some people do chose a mate who is less than ideal due to the lack of an ideal mate however if they find a better mate they do sometimes leave their current mate for the "better" mate

 

[Finch]

Quote[/b] ]its not that im unwilling to accept your examples of speciation, its that i find that they do not come with enough evidence to convince me that they ahve happened, and even if your goatsbeard is a good example, ok thats one, sorry but clinging to one thing is not good science

fine, then i have a few... somewhere. one moment please..

 

[ktulu]

Quote[/b] (TheAlphaWolf @ Jan. 22 2005,8:37)]

Quote[/b] ]In studying the brain chemistry of the two mammals, researchers found that when the monogamous prairie vole mates, the pleasure hormone dopamine is released in its brain. The receptors for that dopamine are located in the brain's pleasure center, which also happens to be where the receptors for the hormone vasopressin are located. And vasopressin is linked to social learning.

"They recognize that this good feeling is associated with that particular female," says Larry Young, a psychiatry professor at Emory University in Atlanta.

In contrast, the dopamine and vasopressin receptors are not located together in the promiscuous meadow vole. So when they mate, "they don't make that specific connection to a specific female, they just think that mating feels good," he says.

When Young and his team took the prairie vole vasopressin receptor gene and injected it into the pleasure center of a meadow vole, the meadow vole suddenly preferred just one partner.

Scientists can't see the receptors in humans yet. But it seems likely, says Young, that this gene is somehow linked to human's ability to form social bonds with others. Other studies have found links between variations in the gene and autism.

of course... vole brains are easier to study because they're "lower" animals and you can make them suffer and experiment with them because we were put here to rule over them..
http://www.usatoday.com/news/science/2004-06-16-voles-usat_x.htm

also monogomy does not appear to be something that is natural to humans, it is culturally imposed. over 75% of cultures on earth allow some kind of polygomy, and that pretty much leaves the western cultures who hold judeo-christian beliefs that having more than one husband/wife is wrong.

 

[TheAlphaWolf]

Quote[/b] ]ok thats one, sorry but clinging to one thing is not good science.

ok, the primrose. species A differed from it's parents which were species B and species A can't mate with species B.

Quote[/b] ]At reasonably low concentrations, copper is toxic to many plant species. Several plants have been seen to develop a tolerance to this metal (Macnair 1981). Macnair and Christie (1983) used this to examine the genetic basis of a postmating isolating mechanism in yellow monkey flower. When they crossed plants from the copper tolerant "Copperopolis" population with plants from the nontolerant "Cerig" population, they found that many of the hybrids were inviable. During early growth, just after the four leaf stage, the leaves of many of the hybrids turned yellow and became necrotic. Death followed this. This was seen only in hybrids between the two populations. Through mapping studies, the authors were able to show that the copper tolerance gene and the gene responsible for hybrid inviability were either the same gene or were very tightly linked. These results suggest that reproductive isolation may require changes in only a small number of genes.

Quote[/b] ]Dobzhansky and Pavlovsky (1971) reported a speciation event that occurred in a laboratory culture of Drosophila paulistorum sometime between 1958 and 1963. The culture was descended from a single inseminated female that was captured in the Llanos of Colombia. In 1958 this strain produced fertile hybrids when crossed with conspecifics of different strains from Orinocan. From 1963 onward crosses with Orinocan strains produced only sterile males. Initially no assortative mating or behavioral isolation was seen between the Llanos strain and the Orinocan strains. Later on Dobzhansky produced assortative mating (Dobzhansky 1972).

etc... I ain't gonna post all of them here

Quote[/b] ]You dont know that those fossils couldnt mate, granted they have many morphological differences, but morphology is not proof of gentic change,

but it is! a t-rex is obviously a different species from a guineapig.

 

[Amateur_Expert]

Quote[/b] (ktulu @ Jan. 22 2005,2:56)]also A_E, there are certain features that are universally considered attractive by all humans, like body ratios in females, or access to resource in males, health is a very big one, and there are a bunch of other i cant remember right now(where is that cultural anthro book) now some people do chose a mate who is less than ideal due to the lack of an ideal mate however if they find a better mate they do sometimes leave their current mate for the "better" mate

Of course, it's human instinct to know who is attractive to them (which depends on your culture and upbringing too) but it isn't a determining factor now. People that are not considered attractive can still find a mate and their genes remain in the genepool. Everyone can expect to be married, because you are ugly it's no exception. You're right, but it isn't definitive as it is in other species.

 

[Finch]

gues what? i have to go somewhere and i cant find it

 

[Amateur_Expert]

Quote[/b] (ktulu @ Jan. 22 2005,2:56)]

Quote[/b] (Amateur_Expert @ Jan. 22 2005,8:49)]

Quote[/b] (D muscipula @ Jan. 22 2005,12:33)]I would actually go a step further and say we are devolving as a species. Almost all natural selection has been removed, both by science and by legislation. In many ways, "political correctness" is little more than the sophisticates' dictate that a person's capabilities and performance should not affect their opportunities, which seems to me to be the fast track to retrogression, both genetic and civilizational.

I've never heard of de-evolution. I don't think its possible. Maybe we are evolving toward a worse state but evolution isn't a process thats reverse, it's built upon.

evolution is based on selection of gene mutations, which can be helpful or harmful. also the "fitness" of differnt geneotypes is based on the enviroment, so what maybe benifical to humans hunting and gathering on the plains may not be helpful, or may verywell be harmfull in a industrialized urban setting.

phenotypes, not genotypes.

 

[TheAlphaWolf]

Quote[/b] ]also monogomy does not appear to be something that is natural to humans, it is culturally imposed.  over 75% of cultures on earth allow some kind of polygomy, and that pretty much leaves the western cultures who hold judeo-christian beliefs that having more than one husband/wife is wrong.

but cultural things have basis on genes too. In basically all other cultures men rule over women so either they marry someone who is polygomous or they don't marry at all, which is considered bad (even in the us it's assumed you will marry and have kids... it may not be considered so bad if you dont but there's still pressure to marry and have kids)... ugh... I lost my train of though... i wish my mom would just... UGH!
so it doesn't matter that it's culturally imposed because that reflects the individuals who make the culture... so...ack... do you get what I'm trying to say?

 

[ktulu]

Quote[/b] (TheAlphaWolf @ Jan. 22 2005,9:02)]

Quote[/b] ]ok thats one, sorry but clinging to one thing is not good science.

ok, the primrose. species A differed from it's parents which were species B and species A can't mate with species B.

Quote[/b] ]At reasonably low concentrations, copper is toxic to many plant species. Several plants have been seen to develop a tolerance to this metal (Macnair 1981). Macnair and Christie (1983) used this to examine the genetic basis of a postmating isolating mechanism in yellow monkey flower. When they crossed plants from the copper tolerant "Copperopolis" population with plants from the nontolerant "Cerig" population, they found that many of the hybrids were inviable. During early growth, just after the four leaf stage, the leaves of many of the hybrids turned yellow and became necrotic. Death followed this. This was seen only in hybrids between the two populations. Through mapping studies, the authors were able to show that the copper tolerance gene and the gene responsible for hybrid inviability were either the same gene or were very tightly linked. These results suggest that reproductive isolation may require changes in only a small number of genes.

Quote[/b] ]Dobzhansky and Pavlovsky (1971) reported a speciation event that occurred in a laboratory culture of Drosophila paulistorum sometime between 1958 and 1963. The culture was descended from a single inseminated female that was captured in the Llanos of Colombia. In 1958 this strain produced fertile hybrids when crossed with conspecifics of different strains from Orinocan. From 1963 onward crosses with Orinocan strains produced only sterile males. Initially no assortative mating or behavioral isolation was seen between the Llanos strain and the Orinocan strains. Later on Dobzhansky produced assortative mating (Dobzhansky 1972).

etc... I ain't gonna post all of them here

Quote[/b] ]You dont know that those fossils couldnt mate, granted they have many morphological differences, but morphology is not proof of gentic change,

but it is! a t-rex is obviously a different species from a guineapig.

ok the primrose, i have to look at that one again, the yellow monkey flower many, not all, of the crosses were infertile, suggesting that if the genes fall right then successful mating can occur. The fact that Drosophila paulistorum did at one time cross means it possible again, and it was only like 8 years later which isnt really enough time to truely speciate, and if the orginal specimens were still being used it is possible they mutated, or that because at one time they were crossed they may not take the cross again.

and yes i know that a t-rex is not a guineapig, however you were talking about hominids which is what i directed that comment at.

 

[ktulu]

Quote[/b] (TheAlphaWolf @ Jan. 22 2005,9:11)]

Quote[/b] ]also monogomy does not appear to be something that is natural to humans, it is culturally imposed.  over 75% of cultures on earth allow some kind of polygomy, and that pretty much leaves the western cultures who hold judeo-christian beliefs that having more than one husband/wife is wrong.

but cultural things have basis on genes too. In basically all other cultures men rule over women so either they marry someone who is polygomous or they don't marry at all, which is considered bad (even in the us it's assumed you will marry and have kids... it may not be considered so bad if you dont but there's still pressure to marry and have kids)... ugh... I lost my train of though... i wish my mom would just... UGH!
so it doesn't matter that it's culturally imposed because that reflects the individuals who make the culture... so...ack... do you get what I'm trying to say?

It does matter that its culturally based, since it is imposing something that goes against hte instincts that humans have. and what cultural features have a basis in genes? i have yet to learn about any, they do affect the gene distributions, and also are basiclly looked at as compensation for not geneticlly adapting to the problems that humans face, but back to my point the most important thing to consider about monogomy is the fact that it is imposed by culture.

ps. not all cultures do women rule over men, alot of them they have some form of equality or in some cases are even ruling over the men.

oh and actully both geneotypes and phenotypes are selected for. Sorry i said geneotypes because i have been doing way too much codominant gene studies in my bioanthro class.

 

[ktulu]

Quote[/b] (Amateur_Expert @ Jan. 22 2005,9:02)]

Quote[/b] (ktulu @ Jan. 22 2005,2:56)]also A_E, there are certain features that are universally considered attractive by all humans, like body ratios in females, or access to resource in males, health is a very big one, and there are a bunch of other i cant remember right now(where is that cultural anthro book)  now some people do chose a mate who is less than ideal due to the lack of an ideal mate however if they find a better mate they do sometimes leave their current mate for the "better" mate

Of course, it's human instinct to know who is attractive to them (which depends on your culture and upbringing too) but it isn't a determining factor now. People that are not considered attractive can still find a mate and their genes remain in the genepool. Everyone can expect to be married, because you are ugly it's no exception. You're right, but it isn't definitive as it is in other species.

although your right, you find a much higher rate of infidelity among people who find their mates as unfit. and also physical attractiveness is not the only thing that matters in a mating relationship between humans, i never said it was all physical did i?

 

[TheAlphaWolf]

Quote[/b] ]The fact that Drosophila paulistorum did at one time cross means it possible again

says who? we can't mate with birds now did we?

Quote[/b] ], and it was only like 8 years later which isnt really enough time to truely speciate

they breed fast and speciation doesn't have a time limit.

Quote[/b] ]and if the orginal specimens were still being used it is possible they mutated,

umm.... isn't that the WHOLE POINT?

Quote[/b] ]and yes i know that a t-rex is not a guineapig, however you were talking about hominids which is what i directed that comment at.

ok... http://www.talkorigins.org/faqs....tes_ex3
we may not know if the last two could interbreed, but the first one and the last one definately couldn't, and there are many fossils in beteween... falling in chronological order... so to say that fossils show some kind of flaw because we don't know exactly where one species begins and the other ends isn't an accurate statement.

 

[Amateur_Expert]

Quote[/b] (ktulu @ Jan. 22 2005,3:35)]

Quote[/b] (Amateur_Expert @ Jan. 22 2005,9:02)]

Quote[/b] (ktulu @ Jan. 22 2005,2:56)]also A_E, there are certain features that are universally considered attractive by all humans, like body ratios in females, or access to resource in males, health is a very big one, and there are a bunch of other i cant remember right now(where is that cultural anthro book) now some people do chose a mate who is less than ideal due to the lack of an ideal mate however if they find a better mate they do sometimes leave their current mate for the "better" mate

Of course, it's human instinct to know who is attractive to them (which depends on your culture and upbringing too) but it isn't a determining factor now. People that are not considered attractive can still find a mate and their genes remain in the genepool. Everyone can expect to be married, because you are ugly it's no exception. You're right, but it isn't definitive as it is in other species.

although your right, you find a much higher rate of infidelity among people who find their mates as unfit. and also physical attractiveness is not the only thing that matters in a mating relationship between humans, i never said it was all physical did i?

Nope you didn't and i didn't imply it. It was just an example.