Study Detects Recent Instance of Human Evolution

by zagor 142 Replies latest jw friends

• 

  Leolaia

  Genetic lactase deficiency (Which was once ostensibly the norm according to human evolution theory) is a condition that starts around the age of two, gradually develops over the next several years as the body produces less and less lactase, and depending upon the individual, sometimes doesn't even fully manifest itself until early adulthood. .... Therefore at lease for me, it's not hard to envision the practice of drinking animal milk arising in stages.

  TD....Exactly, that was my thinking too.

  Canis lupas (The Wolf) is a different species than Canis familiaris (Domestic dog)

  I think since 1993 they have been treated as subspecies of the same species (i.e. Canis lupus familiaris), since it has been documented that dogs can still breed with wolves. However it is not known whether all breeds can mate with wolves, such as chihuahuas. I wonder if in fact speciation has already occurred, or if it is on the cusp of occurring.
• 

  Leolaia

  After reading your post, am I still missing something? Within a family and within a community and within a geographical area extending hundreds of miles in all directions, there are individuals and groups that are lactate tolerant and those that are not. Not all Swedes and Dutch are comfortable with lactate, though most are.

  That's exactly what I'm talking about. If you perceive this as a problem, then you should read my post again because I talked about this....this variability is what evolution expects to find, especially with a process of adaptation that has such shallow time depth. I think the problem is that you are thinking in terms of homogenous groups, as opposed to the very heterogenous character of populations. When an adaptation occurs, its frequency increases throughout the population in a gradual and uneven manner, and variability within populations remains larger than between populations. To better view the spread of the adaptation, you need to compare the Swede-Dutch population as a whole with other populations, such as West Africans, South Indians, or Chinese. Then you will find that the distribution of the mutation is very different than in northern Europe.
• 

  fjtoth

  Well, Leolaia, I appreciate your effort, but I'm still not convinced. Possibly I don't follow you completely because I'm unfamiliar with some terms you use, and I haven't the time to make this a deep study.

  I've been friends of several Japanese families for years. The parents are short, very short, but their kids have grown for the most part to be in the 6-foot-tall range. The change is due to getting away from the Japanese diet and eating Canadian and American foods instead. Neither the parents nor I see this drastic change as a mutation or some other characteristic of evolution. We're certain that if the kids moved to Japan and consumed the standard Japanese diet, their kids would probably be of short stature.

  Some of the parents have grown fat while others are slim and athletic. But their kids don't take after their parents in that respect either. In the area of physical development, it seems more reasonable to me that we humans have built into us a tremendous number of possibilities. I don't see the lactose tolerance discovery as anything more than evidence of that built-in adaptability potential.

  Frank
• 

  hamsterbait

  All babies, no matter where, can digest lactose, until they are weaned.

  After that in most cases, the ability then switched off. If a baby in a non-dairy culture still had the ability to digest lactose, nobody would know.

  The selection process happened when starving people, in desperation ate milk products. The lactose intolerant then would have died, and if they were kids, before they could pass on their genes.

  Mutations happen BEFORE the situation where they prove to be beneficial. They are accidental miscopyings of DNA. This leads to what is called "pre-adaptation" - eg some bacteria in nature have a mutated gene which allows them to tolerate phenolic compounds. So when disinfectants began to be used they were not killed.

  In no way did the germs(assuming they survived) get a signal to change their DNA to tolerate certain disinfectants or drugs.

  The mutation of the AIDS virus has proved this argument already.

  Unfortunately, the Witchtower has Babbled its Tricks so that the average dub really believes that ALL mutations are harmful and damaging.

  Most mutations are not even noticed in the everyday world because they operate on the molecular level.

  For instance - did you know that the humble mouse has a gene enabling it to break down cooked starches?

  If we had not invented baking, would this have been discovered?

  HB

  Sorry Leo - just got to your post!!!!
• 

  TD

  Hi Frank

  By "Hybrid" to you mean "Infertile?"

  I think interspecies fertility is an observation that ultimately hurts the case for creationism more than it helps it.

  You've pointed out that the domestic dog, gray wolf, coyote and most jackal species can all interbreed and produce fertile offspring. If you're aware of which members of the Canid family can reproduce, than you are also probably aware of which ones cannot and why. (e.g. The yellow jackal, Old and New World fox, raccoon dog, etc. cannot reproduce with other members of the Canid family.)

  The situation is similar to that of the Cheetah and other members of family Felidae where a creature that is very obviously related is still genetically divergent enough that reproductive isolation exists. This seems to me to be an untenable situation for the "Species are set in stone" brand of creationist to try and account for. (When they use the term "species" they really mean Biblical "Kind")

  For example, if the swamp lynx and domestic cat are really the same "Kind" because they can mate and produce fertile offspring (Like the wolf and coyote can) and the fact that they are two different species is really not that important, than are the Lion and Tiger "Sort of the same kind" because they can mate and produce infertile offspring? Are the Jaguar and Cheetah two entirely different kinds because they can't reproduce at all?
• 

  hamsterbait

  Frank -

  What you say about Japanese children being taller than their parents is true.

  The thing you need to remember is that most of the meat consumed in the west is from animals injected with antibiotics and growth hormones. These are stored in the fat and flesh of the animals, then absorbed by those eating them.

  Not only is this contributing to the increasing adaptation of bacteria to antibiotics, but stimulating growth in youngsters at an age when they are already shooting up, and starving all the time, thus eating more burgers. I know when I was a kid, I had far rather eat a hunk of cooked dead animal than a fondent french fancy.

  Also, perhaps a pre-adaptation is at work here, as in our ever more image conscious culture, those who are tall tend to be viewed more favorably, and will therefore be more successful.

  I have no beak to cut off, and so cannot succede.

  HB
• 

  M.J.

  I'm trying to understand this here, so please bear with me.

  I understand that within the parameters of all the possible genetic mutations/variations that can occur within a group, the variations that most successfully carry onto successive generations will eventually become dominant within that group.

  However, I'm having trouble understanding how life forms can take on increasing complexity through genetic mutation. No, I'm not talking about "entropy". I see it this way. If you liken the genetic code to a computer code, where each coded function has a range of possible parameters, you can really tweak the parameters, eliminate functions, but how do you introduce a brand new function to the code without some form of external input? I'm not a reader of the evolution/creation debate either way. I just come to my question here out of a curiosity of whether or not anyone has been able to create an adequate computer simulation of evolution. To my knowledge, there hasn't been a successful simulation created yet which satisfactorily demonstrates that it works in principle. If anyone can provide some insight I'm not seeing here, please let me know...
• 

  fjtoth

  TD,

  I didn't have in mind biblical "kinds." What I mentioned was from a Toronto newpaper article that I read some weeks ago.

  HB,

  I doubt what you're saying applies in this case. The Japanese (and Korean) families I know are farmers for the most part. They grow their own food, and rarely go to town to shop. The one family that does buy their food have kids that look almost like twins (same approximate heights) of the kids whose parents don't shop.

  Frank
• 

  one

  The most recent instance of Human Evolution is my leaving the Kingdom Hall for good!

  ROFLOL

  tested, proven, validated
• 

  Leolaia

  Possibly I don't follow you completely because I'm unfamiliar with some terms you use, and I haven't the time to make this a deep study.

  It seems that most of the objections made in this thread involve pretty basic misunderstandings of evolution and population genetics.

  I've been friends of several Japanese families for years. The parents are short, very short, but their kids have grown for the most part to be in the 6-foot-tall range. The change is due to getting away from the Japanese diet and eating Canadian and American foods instead. Neither the parents nor I see this drastic change as a mutation or some other characteristic of evolution. We're certain that if the kids moved to Japan and consumed the standard Japanese diet, their kids would probably be of short stature.

  I'm not sure what relevance this has with the discussion on lactose intolerance. What you have described are non-genetic influences on stature in the life of the individual, while the article describes a genetic predisposition to lactose tolerance, which itself impacts the kind of diet a person can have. No one is talking about the environmental diet-induced change in average Japanese stature as a "mutation" or "evolution" precisely because it is non-genetic! Apples and oranges. This is not an argument against genetic mutations any more than the existence of diet-induced Type 2 diabetes is evidence against the existence of another kind of diabetes. It would be a strawman argument (involving the "either/or fallacy") to claim that genetic changes do not occur since non-genetic changes also occur in a population.

  Some of the parents have grown fat while others are slim and athletic. But their kids don't take after their parents in that respect either.

  You seem to have a Lamarckian (mis)-understanding of evolution.

  In the area of physical development, it seems more reasonable to me that we humans have built into us a tremendous number of possibilities.

  Of course, both as a result of genetic variability (which already include the wide array of mutations as pre-adaptations) and because of environmental factors faced by the organism.

  I don't see the lactose tolerance discovery as anything more than evidence of that built-in adaptability.

  That's what the article is saying; the emergence of lactose tolerance in the general population constitutes evidence of the "built-in adaptibility" of our genes to respond to changing circumstances like diet. But it is more than that....it also furnishes evidence of independent adaptation to the same circumstances in separate populations and also gives some indication of the rate of diffusion of the mutation in the general population.