Junk DNA

[pioneer]

I was taking a break and went for a swim, this idea popped into my head. If you look at the DNA, in almost all cells, the DNA carrys a bunch of genes that have no apparent functionality, in its day to day life. These are often described as junk genes. The question I have is, why is the DNA such a pack rat? It is like the DNA's attic, basement and garage is full of junk it never uses in its day to day activities. The DNA is not a slob. He has all its junk neatly organized. But why does it keep all this junk. It would appear, life would be much easier if the DNA called Goodwill or the Salvation Army and had them come in and clean out the junk. The DNA would be leaner making it much easier during cell cycles.

 

What is even more odd, some tiny creatures, like fruit flies, are even bigger pack rats, than the DNA in far more evolved lifeforms. It is sort of like a 2 year old filling in a warehouse with junk. How and why did the DNA in this little life form collect so much junk, with its activities so limited. DNA is not a slob, but he does appear to go to too many yard sales and antiques shops. He doesn't seem to thrown anything away, even if he never uses it.

 

If you look at the rest of the cell. It is a lean mean protein machine. There is very little in the way of pack ratitis, unless it is preparing to replicate. But even then, everything is functional to the needs of day to day life. The DNA may be the head of the household, but he has a junk problem.

 

When I thought about this, cells run a very tight ship. Maybe this is not junk at all, but is important to day-today operations. We know it doesn't function in anyway to make proteins, for day-to day operation. The only other logical use for it, is it is part of the DNA's configurational presence. It may be sort of like the mane of male lion. This big hair gives him a majestic presence that tells everyone in the jungle that he is the king. If we gave the lion a mullet, he would not be as credible in the jungle. Has anyone ever tries to trim off all the junk genes and see if this matters? If it has day-to-day, configurational ambience, it should definitely matter.

[dichotomy]

I thought the whole "JUNK GENE" theory was gradually being proven wrong? Didn't some scientist buy all the patents to the research use of 'junk genes' in humans?

 

It makes common sense that all of the supposed 'junk' does serve a function. Much of it probably just doesn't serve a function on the convenient scale of time that we would like it to occur on.

 

cheers.

[iNow]

The question I have is, why is the DNA such a pack rat?

Because animals with back-up genetic code and recessive traits have out survived those that did not. Environments change, and life forms suited to only one will die soon enough. Additionally, "junk DNA" is a buzz word that has little to do with what it truly is.

[Paralith]

"junk DNA" is a term many geneticists greatly dislike. The DNA is not junk - it simply does not directly translate into a protein. however, a great deal of it consists of very important regulatory sequences that interact with proteins and other coding DNA sequences to direct the manner in which the "non-junk" DNA is expressed.

[Dak]

at the very least, junk dna serves as a 'damage' trap: certain damage (such as randomly inserting viruses or electric damage) are much more likely to 'hit' the junk dna than the useful stuff.

[PhDP]

... still, a large part of "Junk" DNA is composed of evolutionary artifacts.

[DrDNA]

I think that the answer to your question lies in another: is there an evolutionary or survival benefit to removing "junk DNA" or leaving the "junk DNA" intact?

I believe that there is no advantage to removing unused DNA unless it might be harmful for some reason (in which case the organism might be less fit and die). But having extra DNA around which can provide a template for nonlethal modifications (evolution) often provides an advantage to the organism. Also, much of what was called "junk DNA" in the past has turned out to not be junk at all, and useful.

BTW: I think that it is interesting that software programmers do much the same thing with old code. Other than remove it, they leave it in (but turn it off) and write new code around it. For example, MS Word is filled with generations of old code that is no longer used.

[pioneer]

Let me show another use for junk DNA, with an oversimplified analysis. This is oversimplified because more is going on. If you look at the DNA double helix, one basic observation are the phosphate groups end up on surface of the double helix. Each of these has a negative charge. The difference between just active genes, and active genes+junk, may be 3-10times more negative charge on the surface of the DNA. Again this is oversimplified. That means the very presence of this junk, makes the DNA a much more powerful source of structured negative charge.

 

If we go to the membrane, this pumps cations, with the outside enriched in sodium and the inside enriched in potassium. The net result is the outside of positive and the inside is negative. Part of the potential in the membrane is due to the concentration gradients, where each cation would like to go the other way, to lower its depleted side of the membrane.

 

If we add all the extra negative charge of the DNA with junk genes, this adds addtional things to the entire cell. With the inside of the membrane induced negative by the cations pumps, the DNA is now more repulsive to the inside of the membrane, making it harder to excape. So it is destined to stay suspended away from the membrane. This permanent separation now allows a train of proteins to form, to connect it to the membrane.

 

If CO2 of HCO3- forms in the cell, due to metabolism, the larger DNA can help repel this accumulation of negative charge outward for removal. Also the cations, are not just a concentration gradient anymore. All that extra negative charge, because of the larger DNA plus junk, changes their charge dynamics, so both see the impact of the inside negative. It is more complicated than that. This example was used to show how just the configurational ambience of negative charge, if amplified, by simply making the DNA larger, can have an impact on some of a cell's dynamics. The junk genes or the mane of the lion is felt by the entire cell.

[immortal]

When I thought about this, cells run a very tight ship. Maybe this is not junk at all, but is important to day-today operations. We know it doesn't function in anyway to make proteins, for day-to day operation.

 

Junk DNA's codes for microRna's which is very important in cell differentiation.

[CharonY]

Different kinds of cells have different selective pressures in maintaining small genomes. Basically, unicellular organisms, especially prokaryotes usually keep a smaller, more densely packed genome than eukaryotes.

 

Pioneers theory regarding charges does not really make sense, btw. DNA in eukaryotes is located in the nucleus, a compartment well away from the cell membrane. Prokaryotic DNA on the other hand is free in the cell, closely associated with the membrane, but they do not accumulate that amount of so-called junk DNA (the potential function of these have been mentioned by various posters already).

Moreover the charge is evenly distributed across the DNA. Thus a larger DNA has the same charge per stretch as a small one. If that wasn't the case gel electrophoresis wouldn't work as it does.

[pioneer]

I was not talking about charge density but the total number of charges. In eukaryotes, the DNA is contained in the nucleus. The DNA also packs with packing proteins. These have positive charge to cancel the negative on the DNA. The DNA produces RNA, which also has negative charge. The packing of DNA accommodates other forms of negative charge. If too much negative charge accumulates, via the RNA, some of the RNA needs to leave the nuclear membrane, to avoid super charging the nucleus.

.

In modern cells, it may be harder to see how something simple could have a lot of practical use. But if we assume a pre-cell, without all the protein bells and whistles of a modern cell, the negative charge on the DNA, at the very least, assures the negatively charged RNA moves away from the DNA. The membrane being negative then assures, that the RNA isn't able to leave the cell so easily. It finds its place, between, in the zone that would then become the rough and smooth ER.

 

Here is an interesting observation, after the DNA duplicates and then packs into doubled chromosomes, the nuclear membrane disappears. The packing of the chromosomes neutralizes the negative charge of DNA. The negative charge may be what is stabilizing the nuclear membrane. The nuclear membrane reacts to the new chargeless potential, increasing surface tension. As the DNA separates and begins to unpack, negative charge gets exposed once again and the nuclear membrane reforms.

[dichotomy]

at the very least, junk dna serves as a 'damage' trap: certain damage (such as randomly inserting viruses or electric damage) are much more likely to 'hit' the junk dna than the useful stuff.

 

So, some of the 'junk' is actually a kind of 'back-up', or 'duplicate' dna? Or, it's an insulation material against certain harmful things, like virii?

 

cheers.

[Paralith]

So, some of the 'junk' is actually a kind of 'back-up', or 'duplicate' dna? Or, it's an insulation material against certain harmful things, like virii?

 

cheers.

 

As long as you understand that the "junk" wasn't created for that purpose or anything like that, then yes. The initial reason for junk appropriation varies - but one possible advantage for retaining junk, rather than "removing" it via selection, is that it serves as a damage trap, or a back up, etc.

[lucaspa]

I was taking a break and went for a swim, this idea popped into my head. If you look at the DNA, in almost all cells, the DNA carrys a bunch of genes that have no apparent functionality, in its day to day life. These are often described as junk genes. The question I have is, why is the DNA such a pack rat? It is like the DNA's attic, basement and garage is full of junk it never uses in its day to day activities. The DNA is not a slob.

 

DNA is not a person to be either a "slob" or not a slob. Stop trying to impose human personality on it.

 

A problem is the very nature of natural selection. By it's very nature, natural selection can only addinformation, not subtract it. What's more, accident will "turn off" a gene and remove its start codon. Then all the following sequence is unexpressed. These are called "pseudogenes".

 

Much DNA is also the results of insertions of repetitive sequences -- many inserted by viruses in the past. Fully 10% of the human genome is ALU repeats.

 

"Junk" DNA simply means that it is not expressed as proteins. Much of "junk" DNA is actually control sequences to tell the genes to be turned on or turned off. That is, it is binding domains of transcription factors. Other parts of "junk" DNA is there to get efficient packaging of the DNA into the chromosome and binding with chromatins.

 

Pioneer, the next time one of these ideas hits you, do us all a favor and start reading on the subject before you post. Instead of relying on us to teach you, please try a little self-learning first. Then, if you hit a problem or find concepts that you don't understand, then come to the board.

 

There is a lot of literature on "junk" DNA and the function of non-coding sequences. It would not have taken you long to find some good .edu sites to start reading about it.

[pioneer]

I am aware of the current thinking on the subject. I get the impression it is taboo to discuss anything that makes life simpler. The simple negative charge repulsion dynamics, I discussed, are all logically consistent.

 

I will add a few more. The DNA double helix is covered in negative charge. This negative charge is repulsive to other negative charge on the DNA, and would like to separate and get as far away as possible. The hydrogen bonding keeps the double helix together with all the negative charge making it easier to separate the double helix, compared to if the DNA had been designed not to have any negative charge on the surface.

 

Losing negative charge on the surface what happens we we pack DNA with packing proteins. The packing will cancel out the negative charge for less repulsion. The double helix is now sturdier and the lack of negative charge makes it possible for the DNA to pack tighter and tighter. When we unpack the DNA, the negative charge is again exposed. This causes the DNA to have to spread out due to charge repulsion. The spreading out then makes it easier for the dynamics of transcription.

 

Another observation is, the spread out or active genes are found closer to the nuclear membrane compared to the packed genes. This would suggest that the nuclear membrane is slightly positive. This is consistent with the nuclear membrane disappearing during the condensation of the doubled chromosomes when the DNA is fully packed. There is now little negative charge to help compensate for positive, causing evacuation. The nuclear membrane only returns where the DNA's negative charge is exposed. It has a natural attraction for the exposed negative charge of the unpacked DNA, which then stays close to the nuclear membrane and vice versa.

 

This atrraction puts the active DNA in the best spot to get rid of the mRNA that forms, as the accumulation of negative charge, super charges the nucleus. The nuclear membrane offers a slight positive santuary before being transport out. I would expect the pores of the nuclear membrane will contain proteins with extra hydrogen bonding hydrogen.

 

I am going to go in a different direction to show additional negative charge affects. When the cell enters the cell cycle, the amount of ATP production rise.s It is really high when the DNA is being duplicated. What happens in the cell to make this possible, is the membrane potential lowers. This lowering of the inside membrane negative charge makes charge room for the increasing negative charge of the ATP. Without that change the cell's internal limit of negative charge would be exceeded.

 

I am saying it is one way or the other. The charge adds an addtional layer of bulk dynamics that makes the highly detailed stuff easier. When life was just forming, these bulk affects set the skeleton for improvements.

[DrDNA]

The DNA double helix is covered in negative charge. This negative charge is repulsive to other negative charge on the DNA, and would like to separate and get as far away as possible.

 

If this were true, DNA would never associate. The phosphates are far enough apart that they do not repel each other enough to push the helix apart (charge-charge interactions are actually/relatively/fairly short range) and they are associated with positive counterions (even some divalent counteranions-such and Ni++, Mg++, etc- with can actually bridge the phosphastes), and then the layers of water,...... This is why they are on the backbone.....

 

The hydrogen bonding keeps the double helix together with all the negative charge making it easier to separate the double helix, compared to if the DNA had been designed not to have any negative charge on the surface.

 

Actually hydrogen bonding is only a minor contributor to dulplex stability. It IS the major factor in specificity though. And other interactions actually "keep the helix together". For example, pi-pi stacking interactions, VDW interactions, etc. And then there is entropy from the exclusion of water, which is a huge factor. In terms of helix stability, hydrogen bonding is swamped by these.

 

Losing negative charge on the surface what happens we we pack DNA with packing proteins. The packing will cancel out the negative charge for less repulsion. The double helix is now sturdier and the lack of negative charge makes it possible for the DNA to pack tighter and tighter. When we unpack the DNA, the negative charge is again exposed. This causes the DNA to have to spread out due to charge repulsion. The spreading out then makes it easier for the dynamics of transcription. .

 

I have no responce to this. Perhaps I do not understand the mechanisms of DNA packaging or your description of it.

 

Another observation is, the spread out or active genes are found closer to the nuclear membrane compared to the packed genes. This would suggest that the nuclear membrane is slightly positive. This is consistent with the nuclear membrane disappearing during the condensation of the doubled chromosomes when the DNA is fully packed. There is now little negative charge to help compensate for positive, causing evacuation. The nuclear membrane only returns where the DNA's negative charge is exposed. It has a natural attraction for the exposed negative charge of the unpacked DNA, which then stays close to the nuclear membrane and vice versa.

 

This atrraction puts the active DNA in the best spot to get rid of the mRNA that forms, as the accumulation of negative charge, super charges the nucleus. The nuclear membrane offers a slight positive santuary before being transport out. I would expect the pores of the nuclear membrane will contain proteins with extra hydrogen bonding hydrogen. .

 

I cannot grasp these....

 

I am saying it is one way or the other. The charge adds an addtional layer of bulk dynamics that makes the highly detailed stuff easier. When life was just forming, these bulk affects set the skeleton for improvements.

 

Sorry, but I don't think that the begining was as simple as bulk charge-charge interactions. Certainly, they play some (important) part but if it were as simple as that, seriously bright people wouldn't still be scratching their heads after dedicating their lives to the issue. Perhaps you are elevating the effects of charge-charge interactions at the expense of a very very critical phenom....specific molecular recognition.

 

This sort of reminds me of when I used to work with a bunch of very very bright electrical engineers who wanted to "do bio". They kept trying to simplfy DNA and protein interactions (actually all of the life sciences) into terms that contained just one or two, perhaps three at most, variables (like semiconductor physics). They saw no need to perform any experiments- which were a waste of time, resources, and space (where vacum pumps, wet etch hoods, and coaters should be installed!) and thought everything (all of them- both variables) could and should just be modeled anyway........

Of course, there were (are) many more variables at work, so the whole endeavor eventually imploded on itself and we had to find other ways to occupy ourselves.

[Paralith]

This sort of reminds me of when I used to work with a bunch of very very bright electrical engineers who wanted to "do bio". They kept trying to simplfy DNA and protein interactions (actually all of the life sciences) into terms that contained just one or two, perhaps three at most, variables (like semiconductor physics). They saw no need to perform any experiments- which were a waste of time, resources, and space (where vacum pumps, wet etch hoods, and coaters should be installed!) and thought everything (all of them- both variables) could and should just be modeled anyway........

Of course, there were (are) many more variables at work, so the whole endeavor eventually imploded on itself and we had to find other ways to occupy ourselves.

 

wow. You just summarized what pioneer's been doing ever since he came to this forum. did any of the engineers you worked with ever come to appreciate the complexity of biological systems, or is there no hope?

[DrDNA]

did any of the engineers you worked with ever come to appreciate the complexity of biological systems, or is there no hope?

 

Ah. That was a fun and frustrating period.

I have to say that some (few) eventually got it and now have really exciting, high level careers in nanotech or nanobiotech or microfluidics (for example).

Some gave up early in the game and went back to their comfort zones, for example gave up when they finally realized that they couldn't deposit DNA quickly and easily, with existing tools, everywhere they wanted to by chemical vapor deposition (this - CVD of DNA- came up several times a week in the early days). The phase transition temps (not talking about ds to ss transition temps here) of DNA can be quite elusive ...it seems to be quite difficult to get that beast to go in the gas phase intact Proteins are even worse! One must wonder why anyone would even use this stuff!

Others eventually moved on after mother biological entity refused to yield....Stupid organic molecules....C, N, O, S, H, P.....just too darn many of them in too many combinations...can't be predicted ab initio......yield darn it!

Some still not over it and in looney bins (I mean in their cubicles and refuse to come out).

 

Lady bio, she is a beautiful, complex and stubborn lady who will always do things her way.

 

To be fair, I usually feel pretty small after I've had a conversation with an engineer or physicist about something that they are experts in (or perhaps just knowlegable in) and I have to look a lot of it up just to understand what it was they were actually talking about.....often waaaayyyy over my head.

 

CORRECTION TO WHAT I WROTE ABOVE

"If this were true, DNA would never associate. The phosphates are far enough apart that they do not repel each other enough to push the helix apart (charge-charge interactions are actually/relatively/fairly short range) and they are associated with positive counterions (even some divalent counteranions-such and Ni++, Mg++, etc- with can actually bridge the phosphastes), and then the layers of water,......"[QUOTE]

 

Sorry. Meant to say counterions (positive ones)..not counteranions.

[lucaspa]

Let me show another use for junk DNA, with an oversimplified analysis. This is oversimplified because more is going on. If you look at the DNA double helix, one basic observation are the phosphate groups end up on surface of the double helix. Each of these has a negative charge. The difference between just active genes, and active genes+junk, may be 3-10times more negative charge on the surface of the DNA.

 

Citations? OK, what you are saying is that the "junk" DNA adds more nucleotides and thus more phosphate groups.

 

However, NONE of the effects of this negative charge that you describe actually happen. Besides, you are forgetting the extra energy needed to 1) synthesize and 2) maintain this extra DNA. It would be more efficient just to have the active genes. After all, BACTERIA do!

 

If we go to the membrane, this pumps cations, with the outside enriched in sodium and the inside enriched in potassium. The net result is the outside of positive and the inside is negative.

 

That's not why there is difference in charge. Yes, there is a concentration gradient of Na and K ions, but the net charge is established by proteins that cannot pass the cell membrane. http://www.cvphysiology.com/Arrhythmias/A007.htm

 

If CO2 of HCO3- forms in the cell, due to metabolism, the larger DNA can help repel this accumulation of negative charge outward for removal.

 

Remember, in eukaryotic cells the DNA is in the nucleus and the HCO3 is generated in the mitochondria, which is in the cytoplasm. Thus, DNA can't "repel" it. Also, DNA in eukaryotic cells is surrounded by chromatin -- which neutralizes the negative charges due to the phosphate groups.

 

PLEASE, do some better reading in biochemistry.

 

This example was used to show how just the configurational ambience of negative charge, if amplified, by simply making the DNA larger, can have an impact on some of a cell's dynamics. The junk genes or the mane of the lion is felt by the entire cell.

 

Citations? Please point to papers comparing metabolism in cells with larger genomes with more "junk" and those without. If you don't have those papers, please stop trying to pass off your speculation as "fact".

 

I will add a few more. The DNA double helix is covered in negative charge. This negative charge is repulsive to other negative charge on the DNA, and would like to separate and get as far away as possible. The hydrogen bonding keeps the double helix together with all the negative charge making it easier to separate the double helix, compared to if the DNA had been designed not to have any negative charge on the surface.

 

You are missing the function of the phosphate groups: it is to provide hydrogen bonding with the water molecules to make DNA soluble in water! It also, because it puts the hydrophilic phosphate groups on the outside, puts the hydrophobic bases together on the inside, where the hydrogen bonds between bases 1) make the double helix stable and 2) provide information on which base is complementary to ensure faithful replication of the nucleotide sequence.

 

When we unpack the DNA, the negative charge is again exposed. This causes the DNA to have to spread out due to charge repulsion. The spreading out then makes it easier for the dynamics of transcription.

]

 

But that happens in bacterial DNA WITHOUT the large amounts of non-coding DNA found in eukaryotic cells. Pioneer, when thinking about your hypotheses, always remember what happens in bacteria where we have the same type of DNA but without the "junk". One of the reasons for the packaging of DNA via chromatin in multicellular organisms is to keep some genes permanently turned off: you don't want your heart cells making the proteins that cause your bone to calcify!

http://scienceweek.com/2004/sa041231-3.htm

 

Another observation is, the spread out or active genes are found closer to the nuclear membrane compared to the packed genes.

 

Citation? The recent paper on this I found has nothing to do with charge, but PORES. That is, the pores in the nuclear membrane so that the mRNA can move to the cytoplasm to be translated in ribosomes!

http://www.nature.com/nrg/journal/v8/n7/abs/nrg2122.html

"Cells have evolved sophisticated multi-protein complexes that can regulate gene activity at various steps of the transcription process. Recent advances highlight the role of nuclear positioning in the control of gene expression and have put nuclear envelope components at centre stage. On the inner face of the nuclear envelope, active genes localize to nuclear-pore structures whereas silent chromatin localizes to non-pore sites. Nuclear-pore components seem to not only recruit the RNA-processing and RNA-export machinery, but contribute a level of regulation that might enhance gene expression in a heritable manner."

 

This is consistent with the nuclear membrane disappearing during the condensation of the doubled chromosomes when the DNA is fully packed.

 

Citation? The only time I can find when the nuclear membrane disappears is during cell division. Otherwise, there is nuclear membrane around those areas of the DNA that are packed.

 

I am going to go in a different direction to show additional negative charge affects. When the cell enters the cell cycle, the amount of ATP production rise.s It is really high when the DNA is being duplicated. What happens in the cell to make this possible, is the membrane potential lowers. This lowering of the inside membrane negative charge makes charge room for the increasing negative charge of the ATP. Without that change the cell's internal limit of negative charge would be exceeded.

 

Citation? Remember, ATP is being made in the mitochondria and there is no effect on the cell membrane. And where did you get the idea that there is an "internal limit of negative charge"?

 

Sorry, Pioneer, but your biochemistry is just off. It's interesting to try to make a unified "simple" theory, but it is unnecessary. If you read the literature, there are lots of functions for the non-coding regions -- none of them are what you propose and what you propose is contradicted by the data. Sorry.

 

Actually hydrogen bonding is only a minor contributor to dulplex stability. It IS the major factor in specificity though. And other interactions actually "keep the helix together". For example, pi-pi stacking interactions, VDW interactions, etc. And then there is entropy from the exclusion of water, which is a huge factor. In terms of helix stability, hydrogen bonding is swamped by these.

 

Citation, please? That isn't the data I've seen. True, hydrogen bonding is only about 3-7 kcal/mole (compared with 70-100 kcal/mole for a covalent bond) but there are a LOT of hydrogen bonds in a DNA molecule. Hydrophobic interactions (exclusion of water) is only about 1-2 kcal/mole.

 

This sort of reminds me of when I used to work with a bunch of very very bright electrical engineers who wanted to "do bio". They kept trying to simplfy DNA and protein interactions (actually all of the life sciences) into terms that contained just one or two, perhaps three at most, variables (like semiconductor physics). They saw no need to perform any experiments- which were a waste of time, resources, and space (where vacum pumps, wet etch hoods, and coaters should be installed!) and thought everything (all of them- both variables) could and should just be modeled anyway.

 

For some reason, physicists and engineers think they can be instant experts in biology and biochemistry. The history of medical science is full of such engineers who seriously botched the job. Linus Pauling is the most famous, but there are many others. Somehow, engineers don't seem to learn from the repeated failures.

[PhDP]

Some engineers and physicists have made real contributions to biology. Maynard Smith and Thomas L. Vincent (both made important contributions to evolutionary game theory) were trained in engineering. Many theoricians from the Santa Fe Institute are physicists...

 

In fact I think their training is much better than what we get in biology.

[Paralith]

Some engineers and physicists have made real contributions to biology. Maynard Smith and Thomas L. Vincent (both made important contributions to evolutionary game theory) were trained in engineering. Many theoricians from the Santa Fe Institute are physicists...

 

In fact I think their training is much better than what we get in biology.

 

DrDNA himself said that some of his engineering acquaintances did meet with success in the field of biology. We're not saying it's not possible - just that many of them have trouble adjusting. I agree that their training is better only in that it is more rigorous, which I do think that biology training should be.

[CharonY]

While that may be off-topic, I'd be interested to know how biology training is less rigorous than physics, for instance.

What one can immediately agree on is the better mathematical foundation of most physics projects, but what else?

[PhDP]

I think our training is not as good because;

 

#1; Some courses are too easy. If you take a look at the textbooks used in; "intro. to microbiology", “ecology”, courses related to a particular group or organism… they are so simple; they could easily be used in high school. A few concepts, some things to remember, et voilà ! Of course, it depends of the teacher, still…

 

#2; Biologists are notoriously inept with numbers. I don't like statistics, it's boring, still, it's very important for biologists. In fact, statistics was in great part built for biology. Yet, most universities have only one (very easy) mandatory course in statistics. It's not enough. And what about mathematics! How many ecologists can understand the theoretical works of Peter Abrams or Stephen Hubbell ? Getting some info on an ecosystem, or about the structure of the genome of some drosophilids, it's not enough. We have to use these information to improve our theories. It can rarely be done without some maths.

 

#3; I think one of the weaknesses of biology comes from our need to get a huge amount of information. Given the complexity of our subject, it's normal, however it has a serious drawback. Many students have been able to get a Ph.D. mostly by collecting data, which can often be made even with a mediocre understanding of biology.

[DrDNA]

I have thought for a long time that biology education would benefit it it evolved into a more "professional" system, much like engineering.

I think that the programs often seem to be loosey goosey.....its a free for all.

[Mr Skeptic]

Junk DNA was never pushed by real scientists. That was more the domain of those I like to refer to as "Religious Atheists" and pseudo-scientists trying to conjure up evidence for evolution. People have been finding various uses for "junk" DNA, such as regulation of proteins and genes, spacing, damage buffer, and more. Much of it we still do not understand, but that does not mean it has no purpose.