mellowmorgan

Oh, I suppose that kind of makes sense. I was assuming both had a lethal recessive allele, because that seemed necessary. When he says, "for every lethal recessive that I possess, if I mate with my sister one in eight of our offspring will be born dead or will die young" it seems like that is the assumption because he is saying one in eight of the offspring WILL have the disorder and die young. None of the offspring would have it though if one of them didn't have the lethal recessive allele. Maybe it would have been more accurate to say, "for every lethal recessive that I possess, if I mate with my sister, there is a 50% chance that one in four of our offspring willl be born dead or will die young." I would not say Hamilton is the father to the entire idea of the selfish gene. He is the theorist responsible for first expounding upon kin selection and altrusim, both of which are essential to the selfish gene though. Also, Dawkins gives credit to these men several times and quotes them throughout his book, espiecially W. D. Hamilton. To my understanding, he helped popularize his work.

I got confused while reading a footnote by Dawkins in his book The Selfish Gene (which I so far thoroughly enjoy), elaborating upon why incestuous relations are highly detrimintal to offspring genetically. Here is the full note: “A lethal gene is one that kills its possessor. A recessive lethal, like any recessive gene, doesn't exert its effect unless it is in double dose. Recessive lethals get by in the gene pool, because most individuals possessing them have only one copy and therefore never suffer the effects. Any given lethal is rare, because if it ever gets common it meets copies of itself and kills off its carriers. There could nevertheless be lots of different types of lethal, so we could still all be riddled with them. Estimates vary as to how many different ones there are lurking in the human gene pool. Some books reckon as many as two lethals, on average, per person. If a random male mates with a random female, the chances are that his lethals will not match hers and their children will not suffer. But if a brother mates with a sister, or a father with a daughter, things are ominously different. However rare my lethal recessives may be in the population at large, and however rare my sister's lethal recessives may be in the population at large, there is a disquietingly high chance that hers and mine are the same. If you do the sums, it turns out that, for every lethal recessive that I possess, if I mate with my sister one in eight of our offspring will be born dead or will die young. Incidentally, dying in adolescence is even more `lethal', genetically speaking, than dying at birth: a stillborn child doesn't waste so much of the parents’ vital time and energy. But, which ever way you look at it, close incest is not just mildly deleterious. It is potentially catastrophic. Selection for active incest--avoidance could be as strong as any selection pressure that has been measured in nature." The bold print is where my confusion arose, and probably owes to my poor comprehension of genetics. With an autosomal recessive disorder like albinism (I'm not saying it's necessarily lethal in modern civilisation, but in the wild it is and it's the first thing I could think of), if two siblings carried the alleles heterozygously with only one recessive, then mated, wouldn't it be that 1 in 4 of their children would be albino, not one in eight? I figured this out using a Punnett square. Is this the wrong approach? Please explain this to me, and the proper calculations involved. Thank you.

It seems rather self-destructive, if you ask me, considering that before electricity we used lamp and candlelight, and before that, fire for the majority of our existence. But my guess would've been that distinguishing between lights that are harmful would've required a larger brain, not a single trait like colour or pattern achieved through natural selection, but I'm not so knowledgeable on this topic...

For billions of years, the only bright objects in the night sky were stars or the moon. Night-flying moths used to navigate in a straight line. Today, the instinct to fly toward bright objects causes moths to exhaust themselves fluttering around streetlights and banging against brightly lit windowpanes. This behavior is not adaptive, so why does it persist?

ok so for the gantt charts of a and b, this is what i got. so did i do it right? (i'm pretty confused with this class... so... please help me)

No, it's not unusual. Everyone in my programming class that I've talked to has had problems with this at some point, especially on exams when we are timed. Whenever I have to write a program, the first thing I do is read the instructions over and over until I know exactly what I need to do, and then sometimes write a summary of what I need to do in comment lines in my java file. Based on the instructions I'll try to figure out what variables and methods I need. Then I import my libraries and do all the headers and curly brackets. Obviously, this doesn't require much thinking but still makes me feel like I'm accomplishing something. When it comes to writing out the code, pseudocode helps me to figure out what I need to do. Also PRACTICE, PRACTICE, PRACTICE! I also had a professor last semester that made us write our code out on paper for tests. It was horrible at first, but over time it helped with memorisation.

So on the UML Diagramming on Visio, I screwed up the settings on something and now I can't set the multiplicities on my arrows. Somehow I made it disappear from the edit window that pops up when you double click on the arrow. I can't get it to go back to the way it was. Is there a way to reset EVERYTHING so I can make sure it's fixed?

So for my Bio Lab, I have to write an essay on the spread of cancer throughout the body. Like how and why the cells separate from primary tumour and spread to other parts of the body. I read some scholarly journals but, to be honest, they were totally beyond my knowledge of cancer. They were so in depth, and I'm trying to just weed out the core concepts, since this is an intro class. I came up with some key words, like metastasis and clonal dominance theory, but I can't find anything providing a simple explanation of what clonal dominance is or a list of its major tenets. Is the clonal dominance theory not even a theory yet, and just a hypothesis? Because somewhere I read that it was only a hypothesis... Also, does anyone know specifically why cancer cells might spread away from their primary site? Thanks!

Thanks so much for your reply. Would you happen to know why my biology professor thinks it's 8?

I had an exam a couple days ago asking for maximum number of electrons in the third shell of an atom. The correct answer was 8, but I keep seeing all over the internet that it's 18. I also saw on the internet that elements like uranium and radon have 18 electrons in their third shells. Our textbook, however, does say that the max is 8. I asked my professor about it and he basically just looked at me like I was crazy and was really adamant about it being 8. Please help. I feel really confused at this point...

I assumed that we were confining the definition of life to the biosphere, as we have no evidence of life existing outside of it.

OK, so I'm in a Software Engineering class and we've just been assigned to groups for a project. Our project is to design an object-oriented system using the Unified Process. We can pick whatever system we want; some one suggested a system that does inventory for a bookstore. I don't know, that seemed a bit dull. So I'm looking for some other ideas that are more interesting - but not too complex as this is our first Software Engineering class and we only have until the end of November (of course we won't be constructing or implementing it, just going to end of Design/Elaboration phases). We are voting on a project Thursday so I need to have some good ideas by then! ...So, yeah, please help!

I have Visual Studio and Eclipse but my mean professor won't let us use them in class!

It works now! Yay! I replaced the cont == "Yes" with "Yes".equals(cont) I was so confused why my original didn't work because in c++ it seems to work fine to do this with strings but I guess strings are quite different in java?

Thank you for your reply. I changed my code according to your revisions, and now there are no errors, but it still isn't letting me enter YES or NO, it just ends the program after printing "Would you like to continue?" :/ Your explanation was, to be honest, a bit beyond me because I have a poor grasp of pointers. This is inexcusable on my part because I've taken a prior programming class where we learned about pointers, and so I should know these things.

You're totally right! But, you know, we humans are kinder than that, and tend to try and defy natural selection or work around it. We prolong the lives of humans with genetic deformities and disorders with medical innovations and technology, allowing them to have a chance to reproduce and pass on their bad genes. If we let natural selection take it's course, they probably would not be able to do that. But we can't allow for such things because, as I said, we are kinder than that - with our sense of supposed "morality" and deep interactions with one another. Thus we feel the same about other species, especially those which we have negatively encroached upon in some way.

There are both biological and environmental factors. One example of a biological factor is lack of testosterone production and surplus of estradiol production in men, which makes them more "feminine". Opposite goes for women leading to them being more "masculine". Also, I think it is important to mention the obvious fact that many people have sex purely for stimulation/pleasure, not for reproduction. This has been evidenced throughout time and with a plethora of other species of animals, so why would your sex/gender matter if reproduction was irrelevant?

Sorry! OK, the error message is: PrimeCalculator.java:29: error: cannot find symbol while (cont == "Yes"); symbol: variable cont

OK... so I've just started programming in Java and I decided to write a little program where the user enters a number and the computer determines whether or not it's a prime. The math work behind it is functioning perfectly(I know because I ran it repeatedly without do-while), but my do-while loop isn't, for some reason it exits the loop after one go or gives me an error message about variables). Can you tell me what I'm doing wrong? Thanks! Oh, btw I'm writing it in Notepad++ and running it in command prompt. import java.util.Scanner; public class PrimeCalculator { public static void main(String[] args) { Scanner sc = new Scanner(System.in); do{ System.out.println("Please enter a number greater than 0"); int input; input = sc.nextInt(); int counter = input-1; double remainder=1.0; if (input==1) System.out.println("This is not a prime number"); else{ while ((counter > 1) && (remainder!=0)) { remainder= input%counter; counter--;} if (remainder==0) System.out.println("This is not a prime number"); else System.out.println("This is a prime number!"); } System.out.println("Would you like to continue? (Yes or No)"); String cont = sc.nextLine(); } while (cont=="Yes"); } }

Science is the study of knowledge we have of our universe, and the rigorous methods used to attain it. Since there is currently no knowledge of a god in reality, or in the universe that we can best perceive through science, we cannot "mix" or include him in it. Also, things like intelligent design are neither testable nor falsifiable, which is absolutely necessary in science. I'm not saying that god doesn't exist, but so far we have no reason to believe he does and thus he has no place in science. One day in the future, we might have new technologies that give us proof of the supernatural, just like the microscope enhanced our sight and verified the existence of microorganisms. But until then I say NO WAY to your question.

Oh, sorry, I guess I just misunderstood you. I know that most of the time when these chimeric mice are produced in labs, they do not have the ability to breed with both female and male mice (provide sperm and also become pregnant), but instead have one functioning reproductive organ and another non-functioning one. Maybe a rare few have this ability (though I've never heard of it and I seriously doubt it), but either way this never EVER happens to mice in the wild. Such an amazing, complex ability is a product of thousands of years of evolution, that cannot yet be copied through artificial means. But it does happen to other animals in the wild. Snails and sea hares are true hermaphrodites. They take turns while mating, so that they both provide sperm and fertilize one another's egg.

Hermaphroditism occurs in many different animals, but it is very rare. All mice are not hermaphrodites, so saying that a "mouse is a hermaphrodite animal" is totally false. Chimeric mice, or chimeras, are the only types of mice with both genitals that can also breed with other mice. Chimeras are created as a result of the following process: A female mouse has sex with a male mouse. Two sperm cells are able to reach two of her eggs and fertilize both. An ovum contains the X chromosome only, but a sperm cell can carry either the X or Y chromosome. In this case, one sperm was X and the other Y, so one fertilized egg is XY (male) while the other is XX (female). But then the two zygotes are merged (this occurs either through a rare mutation or artificial aggregation), and develop into a baby mouse with both male and female reproductive organs. But that doesn't mean they are both fertile. Often a chimera can breed, depending on which reproductive organ is fertile. I'm sure in exceedingly rare cases both organs might be fertile. BUT LET ME MAKE THIS ABSOLUTELY CLEAR: IT HAS NEVER EVER BEEN DOCUMENTED THAT AN ANIMAL CAN IMPREGNATE ITSELF. It just can't happen, because if both reproductive systems are complete, which is necessary, then they would be SEPARATE organs (testicles and ovaries) by which the sperm and egg could never come in contact with one another. It is also important to recognize that most chimeras are created in labs through artificial means, via injection or embryonic aggregation, because it so very rare in the natural world.

Thank you so much!

I have become really fascinated with natural parthenogenesis in animals like komodo dragons and sharks. I haven't been able to find any television specials or programmes on it, so I'm just wondering if there are even any out there. I mean, how could there not be? It's so cool! I have also found that very little people know about parthenogenesis. It was never mentioned in my high school biology classes; I only chanced upon it while surfing the internet. Again, I find this curious because it is such an interesting topic. Please give me your thoughts.