Large Hardon Collider

[Chun Liroy]

Why can't there be a biology thread in addition to an astrophysics thread?

[Woozie]

Why can't the biologist just post here and we can make this an all-purpose science thread? With more scientist around we could finally kick the engineers out.

Seriously, I'd welcome biology to this thread. I personally don't know enough about biology to carry on a conversation at your level, so we need to somehow get the other biology people to post here.

[Chun Liroy]

My level? you act like I have higher than a high school edjumacation

[Woozie]

My bad, for some reason I thought you were in college for it.

I don't know if you'd know the answer to these or not, but these are evolution/biology related:

I have a quick question somewhat related to biology. I don't know if you'd know about this or not.

I was talking to a friend last week, and he mentioned that in the fossil records, there were long time periods where there seemed to only be one species of carnivore and one herbivore (this is during the dinosaurs). Did something like this really happen? He said that this made the system really unstable because there wasn't enough diversity. So any natural disaster was going to lead to mass extinctions in those areas. He said genetic diversity may have played a roll in the dinosaurs becoming extinct altogether. I always thought that the meteor was enough to destroy any large land animal regardless of diversity, so when he said this I was confused.

Also, he was talking about a theory someone had come up with that not only were the dinosaurs warm blooded, but probably had higher metabolisms than mammals today. He said that this guy's theory was based on the fossil records. He mentioned that there's normally a certain ratio of predators to prey in a given system, and that this ratio usually depends on the metabolism of the predators. Based on what we found in the fossil records, it would indicate that the dinosaurs were "more" warm blooded than mammals. My friend didn't mention whether or not he actually believed this theory, he was just telling it to me.

I heard on the science channel once that some people think the dinosaurs may have been some sort of mix between warm blooded and cold blooded. So which is it? Do we know what they were?

Is there some reason mammals today don't grow as large as land animals used to? Why don't we have giant reptile-like creatures today? Or giant mammals?

Why did mammals become the dominant species on land?

Why do we give live birth? What were the advantages to that?

PBS has been running a lot of shows lately that are causing me to ask these questions.

[Chun Liroy]

Kinda old but interesting...

Toward A Nanomedicine For Brain Cancer

ScienceDaily (Sep. 9, 2009) — In an advance toward better treatments for the most serious form of brain cancer, scientists in Illinois are reporting development of the first nanoparticles that seek out and destroy brain cancer cells without damaging nearby healthy cells.

The study is scheduled for the Sept. 9 issue of ACS' Nano Letters, a monthly journal.

Elena Rozhkova and colleagues note the pressing need for new ways to treat the disease, glioblastoma multiforme (GBM), which often causes death within months of diagnosis. Recent studies show that titanium dioxide nanoparticles, a type of light-sensitive material widely used in sunscreens, cosmetics, and even wastewater treatment, can destroy some cancer cells when the chemical is exposed to ultraviolet light. However, scientists have had difficulty getting nanoparticles, each about 1/50,000th the width of a human hair, to target and enter cancer cells while avoiding healthy cells.

The scientists' solution involves chemically linked titanium dioxide nanoparticles to an antibody that recognizes and attaches to GMB cells. When they exposed cultured human GMB cells to these so-called "nanobio hybrids," the nanoparticles killed up to 80 percent of the brain cancer cells after 5 minutes of exposure to focused white light. The results suggest that these nanoparticles could become a promising part of brain cancer therapy, when used during surgery, the researchers say.

http://www.sciencedaily.com/releases...0909103118.htm

[Woozie]

I hear about amazing advances in cancer treatment, or promising cures to cancer all the time, and yet cancer is never cured. But then again, that's the same thing everyone else says about carbon nanotubes.

Do we have antibodies that can specifically recognize cancer cells? I always thought our body couldn't tell the difference.

[Chun Liroy]

My bad, for some reason I thought you were in college for it.

I don't know if you'd know the answer to these or not, but these are evolution/biology related:

I have a quick question somewhat related to biology. I don't know if you'd know about this or not.

I was talking to a friend last week, and he mentioned that in the fossil records, there were long time periods where there seemed to only be one species of carnivore and one herbivore (this is during the dinosaurs). Did something like this really happen? He said that this made the system really unstable because there wasn't enough diversity. So any natural disaster was going to lead to mass extinctions in those areas. He said genetic diversity may have played a roll in the dinosaurs becoming extinct altogether. I always thought that the meteor was enough to destroy any large land animal regardless of diversity, so when he said this I was confused.

Also, he was talking about a theory someone had come up with that not only were the dinosaurs warm blooded, but probably had higher metabolisms than mammals today. He said that this guy's theory was based on the fossil records. He mentioned that there's normally a certain ratio of predators to prey in a given system, and that this ratio usually depends on the metabolism of the predators. Based on what we found in the fossil records, it would indicate that the dinosaurs were "more" warm blooded than mammals. My friend didn't mention whether or not he actually believed this theory, he was just telling it to me.

I heard on the science channel once that some people think the dinosaurs may have been some sort of mix between warm blooded and cold blooded. So which is it? Do we know what they were?

Is there some reason mammals today don't grow as large as land animals used to? Why don't we have giant reptile-like creatures today? Or giant mammals?

Why did mammals become the dominant species on land?

Why do we give live birth? What were the advantages to that?

PBS has been running a lot of shows lately that are causing me to ask these questions.

Yeah I'm a bio major and I'd say I have a bit more knowledge about biology than the average high school grad. In high school I took MBio, Biology, Physics (equivalent to 2 years of it), equivalent to two years on chem (kinda botched, shitty teacher, got fired etc), Aquatic ecology, oceanography and biotechnology.

I'm not really familiar about the 1 carnivore/1 herbivore species thing, though as your friend/the scientist suggested I'd assume that would be a very unstable ecosystem because diversity is necessary. I'll look all this up in a second but just off the top of my head, I've heard of the warm blooded theory about dinosaurs.

The reason there are not large animals has to do with the atmosphere and because of the decrease in prey size not being able to sustain the larger mass of the bigger animals.

As far as mammal dominance this is mainly due to the extinction of the dinosaurs due to the volcanic/meteor impact (whichever you believe). The smaller mammals survived the extinction and were able to flourish afterwards, not allowing any room for the dinosaurs to "make a come back" so to speak.

I'm unsure why we evolved to be viviparous, but the most obvious advantage is that we have more protection over the young before they are born, but there are advantages to the other forms.

[Kaylia]

I don't know if it was just me though. Did everyone else learn that electrons orbit the nucleus like small planets around the sun in high school? Or were my teachers just idiots?

Edit: Well it wouldn't be the teachers who were idiots. That's actually what the textbooks said too. We even saw science videos and animations with little balls floating around the nucleus.

If they mention the energy level, I don't really have any issue with this analogy. It's not like the orbit shape really matter in highschool. Doing the analogy between electricity is gravity is going to be a lot easier to understand than talking about schrodinger equation solution and harmonic oscillator.

[Chun Liroy]

I hear about amazing advances in cancer treatment, or promising cures to cancer all the time, and yet cancer is never cured. But then again, that's the same thing everyone else says about carbon nanotubes.

Do we have antibodies that can specifically recognize cancer cells? I always thought our body couldn't tell the difference.

To put it simply, cancer will never be cured in the sense that it will eventually be impossible for anyone to ever get cancer. As far as I know, it's impossible for our antibodies to recognize cancer cells because they are "normal" cells that won't stop dividing. They aren't functional but cell defects happen constantly everyday to our cells so there aren't any antibodies that could differentiate.

[Woozie]

Holy crap I'm an idiot. I came to this site without logging in so there were advertisments in my post on the top of the page. I was like "Wtf, I don't remember posting that. Why did I post an advertisement for health insurance?"

The reason there are not large animals has to do with the atmosphere and because of the decrease in prey size not being able to sustain the larger mass of the bigger animals.

As far as mammal dominance this is mainly due to the extinction of the dinosaurs due to the volcanic/meteor impact (whichever you believe). The smaller mammals survived the extinction and were able to flourish afterwards, not allowing any room for the dinosaurs to "make a come back" so to speak.

The atmosphere thing, is that because there's less oxygen? I know that's why insects are smaller since they have to diffuse oxygen through their body, but I didn't know that applied to animals with lungs.

Did mammals have some advantage over the other small animals at the time? There must have been dinosaurs or other animals that small. So I assume the mammals must have been able to outcompete them for some reason, but why?

[Chun Liroy]

http://www.ucmp.berkeley.edu/diapsids/endothermy.html

Information on whether or not dinosaurs were endothermic.

[Chun Liroy]

Holy crap I'm an idiot. I came to this site without logging in so there were advertisments in my post on the top of the page. I was like "Wtf, I don't remember posting that. Why did I post an advertisement for health insurance?"

lol

The atmosphere thing, is that because there's less oxygen? I know that's why insects are smaller since they have to diffuse oxygen through their body, but I didn't know that applied to animals with lungs.

Again, I don't know so much about dinosaurs XD but the way I thought about it was that the larger you are the more oxygen you need. After the extinction CO2 levels rose so only small animals could survive, as a combination of food resources as well as atmospheric oxygen.

Here's something I found that explains it a lot better than I can.

The main one revolves around the climate of the Earth at that time. Some research suggests that it was much warmer and more conducive to life. With a bigger base, ecosystems could support larger and larger animals. These animals still had to compete with each other for territory and prey, and so the strongest won out more often than not.



The bigger an animal is, the stronger it is, in general. With the abundance of life supporting it, competing predators kept evolving larger and larger to better able to compete. Our current earth supports land animals like elephants and giraffes, and sea animals like whales giant squid. An animal can only grow so large as their ecosystem can support. The ecosystem has to be able to support an entire herd or group of animals, and their prey, and the food sources of the prey.



The lower temperature of the current age limits how quickly plant life grows, and so limits the food for prey for animals higher on the food chain. This is only a theory, and there are many others. It could just be a quirk of evolution that the current dominant species lose survival advantages as they grow beyond a certain size. It is impossible to say for sure.

Did mammals have some advantage over the other small animals at the time? There must have been dinosaurs or other animals that small. So I assume the mammals must have been able to outcompete them for some reason, but why?[/QUOTE]

Did mammals have some advantage over the other small animals at the time? There must have been dinosaurs or other animals that small. So I assume the mammals must have been able to outcompete them for some reason, but why?

More information here. http://news.bbc.co.uk/2/hi/sci/tech/6503045.stm

[Kaylia]

Dinosaurs were the ancestors of birds

Every time I read this, I imagine a T-rex turning into a little bird. Probably not what happened, but it's cooler this way.



About "big" animal being wiped off the surface, isn't it simply because they are not energetically efficient. You dont need to be huge to stay alive and reproduce...and after a certain point, it's wasted energy to accomplish nothing more.

[Chun Liroy]

Surprised there's not as many Biology people as there are Astrophysics. Only a couple people I can think off the top of my head...

[Kaylia]

The only one in astrophysics is Miz. Most of us are picking field where there is a tiny chance of finding a job, instead of none.

[Chun Liroy]

About "big" animal being wiped off the surface, isn't it simply because they are not energetically efficient. You dont need to be huge to stay alive and reproduce...and after a certain point, it's wasted energy to accomplish nothing more.

Well yeah, that's a large reason why the dinosaurs went extinct. Dust blocks sun, plants can't photosynthesize, herbivores can't get enough energy after the plants begin to die, and die, and then the (larger) carnivores die after that. That's part of the reason why T-Rex was a scavenger, why waste energy killing something when you can walk around find dead stuff just laying there

[Chun Liroy]

The only one in astrophysics is Miz. Most of us are picking field where there is a tiny chance of finding a job, instead of none.

Well I just use that term as a catch all for anything dealing with space because I don't really know the niches of the field all that well XD

[Tristam]

My bad, for some reason I thought you were in college for it.

I don't know if you'd know the answer to these or not, but these are evolution/biology related:

I have a quick question somewhat related to biology. I don't know if you'd know about this or not.

I was talking to a friend last week, and he mentioned that in the fossil records, there were long time periods where there seemed to only be one species of carnivore and one herbivore (this is during the dinosaurs). Did something like this really happen? He said that this made the system really unstable because there wasn't enough diversity. So any natural disaster was going to lead to mass extinctions in those areas. He said genetic diversity may have played a roll in the dinosaurs becoming extinct altogether. I always thought that the meteor was enough to destroy any large land animal regardless of diversity, so when he said this I was confused.

Also, he was talking about a theory someone had come up with that not only were the dinosaurs warm blooded, but probably had higher metabolisms than mammals today. He said that this guy's theory was based on the fossil records. He mentioned that there's normally a certain ratio of predators to prey in a given system, and that this ratio usually depends on the metabolism of the predators. Based on what we found in the fossil records, it would indicate that the dinosaurs were "more" warm blooded than mammals. My friend didn't mention whether or not he actually believed this theory, he was just telling it to me.

I heard on the science channel once that some people think the dinosaurs may have been some sort of mix between warm blooded and cold blooded. So which is it? Do we know what they were?

Is there some reason mammals today don't grow as large as land animals used to? Why don't we have giant reptile-like creatures today? Or giant mammals?

Why did mammals become the dominant species on land?

Why do we give live birth? What were the advantages to that?

PBS has been running a lot of shows lately that are causing me to ask these questions.

Love the biology questions, and they're very good, wish I had the answers!

For the species thing, I would speculate that while dinosaurs were quite dominant, there were lots of different species within dinosaurs themselves, it would be like saying there's not enough genetic diversity among mammals right now. Second is that the fossil record always gives an incomplete picture, and we have merely a snapshot of the true range of diversity within an era. That being said, how genetically diverse the dinosaurs themselves were is a GREAT question and I imagine we can only infer genetic differences from the various body plans and how they relate to other organisms from the same period. I would also agree that having a single dominant genetic complement of species such as the dinosaurs would be unstable. As humans became the dominant species but well before civilization emerged, there were periods of time where we were drastically reduced in numbers and nearly wiped out.

For the metabolism thing, I can't remember where I read it, but I think most thought is along the lines that no species can be purely cold-blooded and that everything derives some heat from metabolism. I'm not sure if the debate about dinosaur metabolism (hot-vs-cold blooded) is really settled, but this paper (yes, there is a review article about the cardiopulmonary system of dinosaurs, I was fucking stunned as well), is solidly into the "warm blooded" camp with lots of lines of evidence, but again, lots of different dinosaurs had lots of different body plans, so there may have been shades of grey. I just found it but it looks like a really, really, really cool read.

http://www.rcjournal.com/contents/07.09/07.09.0887.pdf


For mammal sizes, the most obvious answer is that humans hunted everything that was big. But a cooling environment may have played a role as well. I think that the average size of animals correllates roughly with the amount of atmospheric oxygen, for reasons probably related to metabolism as well. But for the life of me i can't remember where I read that.

I know there are serious dinosaur buffs out there. Hope they find this thread!

[Tristam]

I hear about amazing advances in cancer treatment, or promising cures to cancer all the time, and yet cancer is never cured. But then again, that's the same thing everyone else says about carbon nanotubes.

Do we have antibodies that can specifically recognize cancer cells? I always thought our body couldn't tell the difference.

Some cancers can be surgically cured, I know that's not what you mean but I guess technically it counts?

edit: saw a really good talk about targeted delivery of cancer drugs though, if it works it will be nobel prize worthy and the design and how he did it were really cool. If I can find it I'll post a link to the video of the lecture.

[Eliseos]

Why can't the biologist just post here and we can make this an all-purpose science thread? With more scientist around we could finally kick the engineers out.

You'll never get rid of us.