Thursday, November 18, 2010
Yes, we are posting again. And yes, we know you are surprised. (We’re surprised to find we have a blogging life again now that posts are no longer necessary for a class.) So, dear readers, breathe your sighs of relief at our return and get ready for a little something new. Yes, new. Prepare yourself for a backstory…
As we faced our last weeks of our senior year of undergrad we were faced with a list called “Things Every Biologist Should Know.” And of course, being the experienced seniors we were, we knew everything on it.
I could not even type that with a straight face.
We knew maybe half of the list. (We knew a lot more of the list if we put our minds together. But alas, life does not allow lab partners.) So we decided to review, learn, and relearn the topics on the list of things every biologist should know. And what better way to do this than blog about it? That was a rhetorical question. We know there are plenty of more exciting ways.
So join us, dear readers, as we travel through this list. We’ll cover topics like: Microscope use! Taxonomy! Plant stuff! This should be fun for everyone from new biologists to older biologists who did not pay enough attention in 201 (we’re a little guilty here) to people who know nothing about biology.
So why don't we buckle up, and enjoy the ride.
Tuesday, April 27, 2010
Monday, April 26, 2010
Recently, there has been research on color change and its effects on predator avoidance and social interaction. Specifically, one study, Colour change and assortment in the western rainbow fish, written by Rodgers et. al., looked at this dynamic interaction. The authors used controlled experiments to assess the influence that body pigmentation has on shoaling.
This area of research is not very recent, many studies on color change, mimicry, and coloration anomalies have been done. So what makes this one special? Well, many papers that have been published regarding color change in respect to predator defenses and other interactions have used artificial coloration of the fish (or other study organism) and not natural color change. The authors of this paper argued that the artificial coloration gives less conclusive results because predators in the wild use natural coloration to choose their prey. The major goal of this study was to investigate the relationship between color pattern change and grouping decisions. They tested the relationship by exposing the individuals to different colored environments for two weeks and observing their subsequent grouping behavior.
The results of the experiment supported the hypothesis.
One example from their results is that the fish exposed to the dark aquaria showed a darkened body color patterns and preferred to associate with other dark colored fish. The figure above was taken from the paper, showing the coloration differences between the fish that were kept in the dark aquaria (left) and the fish that were kept in the pale aquaria (right). The take home message from reading the paper was that there is more to the coloration than what it seems. This paper in particular focused on the impact of color on shoaling preferences and anti-predator defenses, but it also provided information on other related concepts. The paper is a great resource for information about color change in the wild, the benefits of color change, and the mechanisms behind schooling and shoaling preferences.
Colour change and assortment in the western rainbowfish
Tuesday, April 20, 2010
Do you have a friend whose laugh can be heard from miles away? Are you able to pick one of your friends or family members out of a crowd based on their laughter? Recent research has shown that humans are not the only animal with a distinct laugh. That’s right, dear reader, a study from the
Researchers Frederic Theunissen and Nicolas Mathevon have been studying the giggle calls of a group of spotted – also known as ‘laughing’- hyenas (Crocuta crocuta). Theunissen defines giggles as “short staccato outbursts they make when they are not getting what they want.”
Hyenas live in clans that vary from ten to ninety individuals. They can hunt on their own or they can collaborate to bring down larger prey. However, both forms of hunting cause intense competition.
Hyenas have ten different types of vocalization, including the giggle call. Hyenas giggle in response to stressful situations or to conflict. For example, a hyena will giggle when being chased away from a carcass by a larger animal or when it is fighting with another hyena over a carcass. After all, the only thing worth fighting over is food, and who wants to hand over a fresh carcass?
UC Berkeley has a colony with 26 hyenas. There were 14 adult females, 10 adult males, and 2 sub-adult males. The two sub-adult males were less than two years old when the study was conducted. The vocalizations of the hyenas are recorded during feeding time at the colony. The pitch variations in the vocalizations are then analyzed. One result of the analysis of these vocalizations is that a giggle can give clues to the age of the hyena. As a hyena ages, the pitch of the giggle goes down.
In a clan of spotted hyenas, there is a complex social system with separate male and female dominance hierarchies. Interestingly enough, males are not always dominant over females. There are examples of “hypermasculinized” females that dominate over males in the clan. Analysis of these vocalizations has shown that the giggle is not linked directly to the sex of the hyena- but instead to the social status.
Theunissen and Mathevon believe that these calls in addition to other sensory forms of communication allow for many channels of communication that supports the complex hierarchy and social system. It is not unheard of that several types of cues are used for communication. Many animals rely on sound cues in addition to chemical and visual cues. These cues can lead to information about other animals such as sex and kinship. Hyenas are no exception to this, except that the acoustic cues of the vocal calls have become very important in the social hierarchy. Subordinate hyenas have a giggle that is very different from the giggles of dominant hyenas.
Dominant hyenas have a giggle that can be described as stable and confident. On the other hand, subordinate hyenas have a giggle that is extremely variable and erratic. Think of it this way- you are in lecture and you hear the professor make a joke. The students who understand the joke laugh like there’s no tomorrow (they would be the dominant hyenas). The students who have slept the entire semester laugh quietly to themselves because they are not sure how funny the joke actually is (these people are like the subordinate hyenas). Every student in the class is now able to tell who knows the topic and who could not care less. This is exactly how a hyena clan works.
As an example, Theunissin says that the more dominant hyenas have giggles similar to “he -- he -- he -- he”. The subordinate hyenas have giggles that sound more like “he hi -- ha – he.” If you want to hear the differences yourself, follow this link to the UC Berkley News.
By listening to the vocalizations a hyena makes, other hyenas can assess a situation. Hyenas that hear the giggle then decide whether or not they should join forces with the hyena producing the vocalizations. It also can be a sign of submissiveness. The erratic giggle of a subordinate hyena may show that the subordinate hyena will act compliantly with the dominant hyena. There are countless situations in which a hyena will make decisions based on the giggle that is heard. Think of it in playground terms: wimpy kids will stay away from the bullies and the bullies will pick on the wimpy kids. Not that I’m in any way supporting bullying, it’s just a good metaphor for this hierarchy. In this case a carcass is similar to lunch money- that’s not too far of a stretch is it?
Alright, I’ll cool it with the metaphors and analogies from here on out.
The point is that the giggle calls of the spotted hyena carry information about the sender such as dominance and age. They may also allow for individual identification. Unfortunately, no one knows for sure exactly why hyenas produce giggle calls, but researchers can still hypothesize. Theunissen and Mathevon bring up many advantages of giggling in their paper; for example, giggling can rally other hyenas to a carcass which might be taken over by a lion. In addition, it is important to note that this study was carried out in captivity and therefore some bias is present. Overall, hyenas are extremely complex and interesting animals- despite the bad name that the Lion King has given them. There is a lot more work that can be done with hyenas which could lead to many discoveries and a greater understanding of social relationships and animal communication.
- Mathevon, Nicolas, Aron Koralek, Mary Weldele, Steve Glickman, and Frederic Theunissen. "What the hyena's laugh tells: Sex, age, dominance and individual signature in the giggling call of Crocuta crocuta ." BMC Ecology. 10.9 (2010). doi: 10.1186/1472-6785-10-9
- "Giggles give clues to hyenas social status." News Center. US Berkely News. US Berkley, 2010. Web. 20 April, 2010.
Friday, April 9, 2010
I will not be blogging about ethology or a specific article today, but about animal treatment instead. Animals are important, ok? I would be willing to bet that almost everyone I regularly come into contact with has heard about unethical treatment of animals on factory farms. But I would also be willing to bet that almost no one I come into contact with regularly is too worried about the treatment of animals on factory farms.
No, I am not a vegetarian or vegan. No, I am not going to tell you to watch some gruesome PETA video. No, I'm not asking you to give up meat for good.
All I want to do is raise awareness a little. At most, I'm just asking you to think about how you can make a difference without changing your daily habits. Is that too much, dear reader?
Factory farming is a huge issue all over the world, and the United States is no exception. Factory farms not only make animals live in terrible conditions, but they also cause air pollution, are sources for antibiotic resistant bacteria, and decrease biodiversity.
The Meatrix is a site that provides informative but still entertaining videos (using the Matrix movies as a basis) about the secrets and harms of factory farming. The site lists the issues and how you can help without changing your way of life- and without asking you to become vegetarian. Check out the video below- the first in a three part set- that exposes factory farming. Then check out the website to see what you can do to help diminish the unethical treatment of animals in factory farms.
Monday, March 22, 2010
Tuesday, February 23, 2010
Once ingested, the fungus causes insects to become delirious and disoriented, and some species of Cordyceps can even cause the insect to climb a plant and attach to a branch. The rest of the process...well its better if you see it yourself.
To those of you who read our very first blog post way back in January, the names Tinbergen, Frisch, and Lorenz might ring a bell. These three guys were geniuses in the world of animal behavior. I'd like to let the readers know a bit about the three fathers of ethology. These guys founded ideas and made discoveries that I guarantee almost everyone knows about, but most people don't know where those ideas came from.
Dear reader, I would like to introduce you to Nikolaas Tinbergen. He is the one who cemented the four main questions a person should ask when studying animal behavior. Let's say, for example, you are watching your dog chase his own tail. Let's also say you are really bored and want to delve deeper into this behavior. You ask yourself these questions: What caused my dog to chase his tail? Has my dog chased his tail since he was a puppy, and will he stop as he gets older? Do other animals chase their tails? Does this affect my dog's chances of survival? Voila! You have just become an ethologist. That's right, if you have ever questioned the behavior of an animal and considered the answers to those questions, you thought scientifically. Don't worry, I won't tell anyone, I know you have a reputation to protect.
Have you ever wondered why bees are so crazy? Well so did Karl von Frisch. Frisch worked with honeybees and carried out research on bee behavior. I'd be willing to bet that you know that bees often perform little dances in order to communicate. (If you didn't, well now you know. And knowing is half the battle...) We have Frisch to thank for our knowledge on bees and for the studies on other social insects that stemmed from his research. And yes, he is wearing lederhosen in this picture. He was Austrian, therefore that choice in clothing is acceptable.
And last, but certainly not least, I'd like to introduce you to Konrad Lorenz. I'm going to go ahead and assume that most people have heard of imprinting. (Thanks, Twilight books) The idea that types of learning, such as identifying a parent, can be automatic at a young age can be attributed to Lorenz. He even experimented by having baby geese imprint on him as their mother figure. As a result, the geese followed him around as though he were their mother, despite the fact that he was of a completely different species. His research and his books are truly fascinating.
Forms of science are every where in daily life. We have people like Tinbergen, Frisch, and Lorenz to thank for information we have come to take for granted. It just goes to show that people do not need to be superheroes to make a difference. You don't need to be a musketeer to fight for the King of France. Is that inspiring enough for you?
Monday, February 22, 2010
The bat-eared fox species is an endangered species of canid that lives in the African savanna. These foxes are nocturnal and monogamous, with a diet of mostly insects. They may also eat small rodents, birds, eggs, and even fruit. But enough of the boring facts! You want to see these little guys in action? Check out the behavior of the bat-eared fox in this video from National Geographic.
It is interesting to note that unlike many animals, male bat-eared foxes are very invested in the rearing of their young. As you can see in the video, males are very protective of their female young and will not let the females mate unless the young courting male asks him first. One more interesting fact to leave you with is that these canids are extremely important in termite control in Africa. One bat-eared fox can eat over one million termites a year!
If you want to know more about engdangered animals or what you can do to help, visit the website for the Wildlife Action Group.
Monday, February 15, 2010
What is denialism? It is defined as "the practice of creating the illusion of debate when there is none." A better way to say it is- when someone tries to argue against something that is supported by facts and/or other evidence. This train of thinking can hinder any debate over any topic. It is kind of like a disease...
You may think that the comparison of denialism to a disease is a little harsh, especially since we all are capable of falling victim to it. I know I've given in to denialism at some point. For example, I am a Miami Dolphin's fan (and I can hear all you football minded people reading this and chuckling- don't judge). So what if I yell at the referee sometimes when I think he is throwing too many yellow flags against my team? Most sports fans are guilty of this. But it is harmless, right?
Wrong. Well, it can be harmless when applied to sports, but what about bigger issues? What happens when someone has such a firm belief in one side of an argument that no scientific fact will ever sway them? It can turn dangerous. Global warming, evolution, AIDS, tobacco causing cancer- these are all big issues in which denialism can take root. What if you grew up in a house with parents who told you tobacco had no negative effects? What if, because of this, they were both chain smokers? What if they got lung cancer? This is simple correlation and causation. However, if you were a denialist, nothing that you just read would matter. If you truly believed that tobacco could not cause cancer, then not even the most well founded evidence would convince you that you are wrong. This is what makes denialism dangerous.
Not only do denialists discredit evidence, they will fight back. Here's how...
- Conspiracy- this is when a person will suggest that the known evidence came from scientists or politicians with ulterior motives.
- Selectivity- when denialists will use facts from the other side that have since been discredited. Denialists will find a flaw in the opposing argument and blow it out of proportion.
- Using another "expert"- an expert (most likely a doctor of another field) will join in and say that opposing data is flawed and lacking substantial proof or significance
- High expectations- denialists often dare others to provide absolute proof that would be, in a word, undeniable
Want to read more about denialism? Check out denialism.com.
Another way the general public can be turned away from science is through scientists themselves. Now, as a science major who is friends with other science majors, I know we like to blame everyone but ourselves. Unfortunately, some scientists can do wrong (no way!) and mislead the public. As Michael Specter discussed on his podcast on Science Friday, scientists sometimes tend to romanticize science and give unrealistic expectations on developments. When science "fails" to deliver those promises, the public gets disappointed and rejects science.
The public is generally going to believe what they want when it comes to moral issues, void of scientific merit. The first caller on the Specter podcast was a perfect example of that. We, as scientists, can only hope that we can have a positive influence on the general public and try to hold their attention long enough to educate them about certain concepts. At least the ones that could prevent illnesses or may be beneficial to their health.
Sunday, February 7, 2010
Anyway, those of us with a scientific brain may also look at the situation and think that this phenomenon is easily explained by survival of the fittest. Jerk looks better than nerd. Jerk can beat up the nerd. Jerk gets the girl. Problem solved. This may be common in nature, but it is not universal. We see the opposite in humans often enough. I'm going to go out on a limb here and suggest that most females actually prefer a male that is sensitive to her needs. Amazingly, humans are not the only species that show this preference. While many female organisms tend to show preference towards the more fit and aggressive males, female water striders prefer the more laid back and sensitive males.
Water striders are insects; you have probably seen one resting on top of water in a stream or pond. A recent study found that female water striders tend to reject the more aggressive and persistent males. Females will leave areas where they are hounded by extremely aggressive males and move to areas with males that are less aggressive.
The result of this preference? Both the aggressive males and non-aggressive males are able to reproduce. The hyper-aggressive males still reproduce due to the monopolizing of females. However, it is the less aggressive males that are reproducing more overall.
This study shows that more cooperative males have a better chance of reproducing than selfish males- at least when it comes to water striders. It's good to see an example in nature that you do not have to be the biggest, best-looking, or meanest male to get the ladies (or vice versa for you females). Pardon my stereotype- but that's good news for us scientists.
Tuesday, February 2, 2010
And apparently, they're not so intelligent.
A recent study was done to attempt and condition the Africanized honey bees. In the experiment, researchers would administer a puff of jasmine odor and follow that immediately with sugar water on the antennae. Another puff of jasmine was administered, and if the conditioning succeeded, the bees would react by immediately protruding their proboscis (tongue-like structure) out to receive the reward. This was also done with the european honeybees to compare results. About 50% of the European bees responded during the first trial, where about 25% of the Africanized honeybees responded. After three trials, the European honeybees were up to about a 75% response and the Africanized were at about 50%.
So, what the Frisch? (it doesn't get old), why don't they learn as rapidly? Well, there's a couple of ideas. One researcher suggests that its simply too costly for the hybrids to "get smarter" and these bees use that energy for their competitive abilities instead (killer bees are invasive). Another idea is that since they are a hybrid species, maybe its a reflection of the two separate backgrounds. The support behind this idea is that African bees come from an area where flowering is triggered by the rainy season, and not so much olfactory and sight.
Whatever the correct reasoning is, it's pretty clear that more work can be done on these insects. If you want to read more, here is the full article.
Monday, February 1, 2010
Meet Dr. David Dosa, a geriatrician and professor who works with patients with dementia in a nursing home called Steere House. Meet Oscar, an antisocial cat who cuddles up with patients who are about to pass away. Understandably, Dosa was very skeptical about Oscar's talent when he first heard about it. However, 5 years later, Dosa and colleagues have totaled about 50 cases when Oscar joined a patient in bed only a few hours before the death of that patient.
But how does Oscar predict death? There are several theories. Most believe it has to do with the smells of certain chemicals that are emitted when a person is dying. Animals have a much more keen sense of smell than humans and can distinguish this. Other theories include that animals may be able to sense sickness or even the shutting down of organs.
Steere House has several other cats in residence, yet none of them exhibit the same talent as Oscar. So why does Oscar find it necessary to be present with patients in their final hours? One theory is that Oscar is simply mimicking the behavior of the nurses. Another suggests it may be as simple as the fact that Oscar enjoys the heated blankets that are placed on dying patients. I personally disagree with the latter opinion. One story is that the nurses tried to place Oscar with a patient whom they believed was within hours of death only to have Oscar run away. If he simply wanted to lie on a heated blanket, he would have stayed. To finish the story, Oscar returned on his own to the still alive patient two days later. As the story goes, the patient did pass away a few hours after Oscar's return.
Despite whatever any one theorizes, we will never know why Oscar likes to be present with dying patients. Many people have labeled Oscar the "furry angel of death". Personally, I don't view Oscar's actions in so morbid a way. Oscar is providing comfort to these people in a time and place where they might otherwise have none. He is a gift to those at Steere House. I wish we could all be so lucky to have something as cute and cuddly as Oscar with us in our final moments. An angel of death? I think not. Maybe just an angel.
Want to know more about Oscar and his amazing talent? Check out the book by Dr. Dosa- Making Rounds with Oscar: The Extraordinary Gift of an Ordinary Cat.
Friday, January 29, 2010
For more information, please visit http://www.scienceandentertainmentexchange.org
Tuesday, January 26, 2010
Altruism is when one individual's actions lessen the fitness of that individual while increasing the fitness of another individual. Too jargony? Lets say Sam and Dean are brothers and need to jump from a burning plane to survive. There is one really old parachute and one really new parachute. Dean lets Sam have the good parachute. This is altruism. Dean may now end up squashed against the earth and never reproduce because he chose the ancient parachute. However, Sam will most likely survive to carry on the family line. Dean and Sam both win, because passing on genes from your gene pool (even if they are not directly your own) still counts.
So back to the deer mice. The deer mice want to pass on their own genes more than anything else. But what if you are a promiscuous species of deer mouse, and the females of your species successively mate with different males only a minute or two apart? How the heck are you going to ensure that your sperm make it to the egg first? Evolution has come up with the answer: cooperation.
The scientists studying the sperm have discovered cooperation among sperm of promiscuous species of deer mice. Rodent sperm have a hooked head so that individual sperm cells can cluster together and swim towards the goal as one. This gives the sperm of that male a competitive advantage and therefore increased chances of sperm from that male getting to the egg first.
I'm quite aware this has little to do with animal behavior, but sperm behavior counts as similar in my book. Anyway, the take home message is- competition is good, but team work is more important. Or you could just stay in a monogamous relationship and that would make things easier evolutionarily. Now, how to pass that message onto the deer mice?
So here we are, two science dorks looking for answers in a world filled with useless information.
By the way, if you want to read the entire Nobel presentation speech, follow the link below. It's got a German translation as well!