Primatology.net

It seems that despite the wealth of information we know about primate behavior, especially chimpanzee behavior, we cannot fully grasp nor explain infanticide. In my opinion, primatology has not yet full investigated this unique and complicated behavior… well at least not until now. Before I get into the thick of new research on infanticide, let’s first define the term. Infanticide is defined as the killing of an infant and it is known to occur in many primate species. Most often in primates, and in other species, it is thought of as a male trait.

Take for example lions, when a male lion becomes head of a pride, he most often systematically kills all lion cubs. It sounds harsh. An unsupported evolutionary hypothesis for this behavior is that the male ‘wants’ to ensure his efforts as a leader influence the survival of his offspring and not the offspring of others… the whole selfish gene concept. The same could be said for male primates when they kill infants in their groups.

There is no explanation for when females engage in infanticide. Some justify female led infanticide as a pathological condition, where there’s something wrong with the female’s psychology. Surely it seems crazy, that the female, who invests so much time and energy and one of her eggs in rearing offspring, to kill one of her own. It gets a bit more complicated as far as jealousy/craziness when females begin to kill another’s infant. The pathological condition is what was hypothesized from Jane Goodall’s observations around the 70′s,

“Passion and Pom, a mother-daughter duo who cooperated in the killing and cannibalization of at least two infant offspring of other females.”

In a new Current Biology paper titled, “Female-led infanticide in wild chimpanzees,” authors Townsend et al., report three instances of female-led infanticidal attacks among the Sonso chimpanzee community in Budongo Forest in Uganda. From what they observed, they speculate these situations of female led infanticide are due to competition for limited resources. From ScienceDaily,

“Alerted to the killings by sounds of chimpanzee screams, the researchers directly observed one infanticide, and found strong circumstantial evidence for two others. Evidence suggested that in two of the cases, the killings were perpetrated by groups of resident females against “stranger” females from outside the resident group. Infants were taken from the mothers, who were injured in at least two of the attacks; in at least one case, adult males in the area exhibited displaying behavior, with one old male unsuccessfully attempting to separate the females.

The authors point out that these new observations indicate that such female-led infanticides are neither the result of isolated, pathological behaviors nor the by-product of male aggression, but instead appear to represent part of the female behavior repertoire in chimpanzees.

What drives the behavior is not yet clear, but may stem from demographic shifts that alter sex ratios and put increased pressure on females competing for foraging areas. In their report, the authors note that the Sonso community had experienced a significant population increase in the ten years prior to the infanticide observations (42 individuals in 1996 to 75 in 2006), and that there had been an influx of at least 13 females with dependent offspring since 2001. The population changes resulted in a highly skewed male:female sex ratio of 1:3, with relatively few males available to increase the home range.”

So there you have it, infanticide in this situation seems to be a numbers game — a means by which members of a chimpanzee community regulate population growth by taking into account the growth in the number of females in relation to growth in the number of males.

I doubt it is really as simple as that but it does provide us a bit more relevance to understand what is going on in the minds of these chimpanzees. We actually have a working model to base infanticide off of. I think we have proven time and time again how complicated chimpanzees are, they rival us in behavioral complexity. As hard as it is to derive why humans kill one another, it is equally challenging to pick that information out of a non-human species we observe in the wild. But this is a step into the right direction.

Oh, have you heard of the Great Gorilla Run? It is a fund-raising event, and the soonest run will take place on Sunday, June 10th 2007 at San Francisco’s Golden Gate Park. The run is organized by the Gorilla Organization, an international charity working to protect the survival of gorillas in their natural environment. With Mountain gorillas the most endangered species of gorillas (only about 400 of them left in the wild!) it is imperative any conservation effort for gorillas be taken. As the site advocates,

“By taking part in the Great Gorilla Run and raising money, you can make a real difference. Your donation will make a future possible not only for the mountain gorilla and the fragile forests they call home, but will support the livelihood of communities and children in need. Your effort to do something is one that matters.”

The premise of the run is kinda funky, participants all dress up in gorilla costumes and run 7K or 4.3 miles. I imagine it will be a very hot and dehydrating run but definitely worth it. I’m putting up a couple photos of the previous event on this post, but there’s also (a dated) video too. The minimum entry fee to participate in the run is $400, as far as I can tell, and if you wanna run in the SF event there is still time to register.

Sorry about cutting it short with the announcement, I know June 10th is just around the corner. If I had known any sooner about the Great Gorilla Run, I woulda surely told you much sooner. You know, to help spread the word. Unfortunately though, Betsy found out about it yesterday and sent me a message with a link to it. I just had to post about it despite the fact it is rather short notice.

If June 10th is not your thing or that San Francisco isn’t easily accessible to you, there will be another run! No worries! The next Great Gorilla Run is scheduled to take place on the 22nd of September, 2007 on a Saturday in London! I think it is priced similarly, but in Pounds instead of Dollars. They say,

“All we need you to do now is pay a £100 registration fee and make a pledge to raise a minimum of £400 sponsorship for the Gorilla Organization.”

If you are interested, please participate. Also, please help spread the word about this wonderful and creative conservation charity event. You can do that by digging (to your right), emailing the site URL (http://greatgorillarun.org) to your friends and families, and blogging about it on your own personal blogs.

One of our more popular posts of all time has been the photos of the tiger and orangutan friendships I shared with you several months back.

To rekindle that interest, I’ve come accross a Reuters news piece on a similar friendship… but this time it is between squirrel monkeys and giant South American rodents called capybaras. And it is all taking place in a Japanese Zoo, Tobu Zoo.

An interesting cultural sidenote, I was reading about capybaras last night and how in countries like Venezula and Brazil, the capybara is to Easter as turkeys are to the United States’ Thanksgiving. That’s because Catholics consider capybaras a fish, mind you, because they live in water and thus are not considered meat for Lent. Crazy, I know.

But I digress, the photo to our right is of one such compainionship between the two species. The news blip on this gets way too technical, hypothesizing whether this is a unique frienship or it can happen in the wild and injectures of meekness, etc. While both species inhabit South America,

“their paths do not cross — capybaras live on river banks while the monkeys live in forests.”

Read the rest of this entry »

I’m posting this as I run out the door, so forgive me if it is a bit brief and incomplete in explanation… but I have to share this resource/paper with you because less than 1 month ago the Macaque genome draft was released, and this publication is the first application, I know, of the draft of the Macaque genome we read about.

It is a library of unique SNPs to Macaques. SNPs stand for Single Nucleotide Polymorphisms and are defined as inter-individual variations in the genetic code at the level of one nucleotide. They help determine population similarities and differences, as well as operate as genetic landmarks useful for recombination analysis and mapping. This project was made by,

‘pyrosequenc[ing] an animal from western China to maximize diversity when compared to the draft sequence from a rhesus macaque of Indian ancestry.’

It was also made using the 454 sequencing method, famous for its application in the Neandertal genome sequencing project.

Here’s a link to the open access publication, “MamuSNP: A Resource for Rhesus Macaque (Macaca mulatta) Genomics,” and in case you ever wanna compare SNPs here’s a link to the project’s website. Okay, I gotta run, bye!

So if you have been in the dark about what’s been making a lot of buzz around the internet today, have no worries. I’m more than happy to explain it to you, because this new research will really help us understand what it means to be human and non-human.

How, you ask?

Well, it identifies a unique protein in human brains and compares that to chimpanzees. This form of comparison is important. Often, I’ve told people that, while it maybe significant that chimpanzees and humans share a remarkable amount of genomic similarity, where we don’t share similarities, areas that span millions of base pairs, the developmental implications are really dramatic.

The research is hardcore molecular biology, specifically proteomics. Proteomics is a branch of molecular biology that seeks to determine the large scale patterns of protein expression and function. The researchers, led by Dr. Bing Su of the Chinese Academy of Sciences in Kunming, China, show,

“a certain form of neuropsin, a protein that plays a role in learning and memory, is expressed only in the central nervous systems of humans and that it originated less than 5 million years ago. The study, which also demonstrated the molecular mechanism that creates this novel protein.”

The publication, ain’t out yet. But I’m getting this all from EurekAlert, a very trustworthy pop-science news outlet run by Science. The divergence time of this protein falls in line with newly assessed dates of human lineage divergence from other great apes. So it has got that going for itself.

The specific paper will be published in Human Variation.

Su had an idea on where to look and what to compare, because her previous work had shown a longer form of the protein, neuropsin II,

“is not expressed in the prefrontal cortex (PFC) of lesser apes and Old World monkeys. In the current study, they tested the expression of type II in the PFC of two great ape species, chimpanzees and orangutans, and found that it was not present. Since these two species diverged most recently from human ancestors (about 5 and 14 million years ago respectively), this finding demonstrates that type II is a human-specific form that originated relatively recently, less than 5 million years ago.

Gene sequencing revealed a mutation specific to humans that triggers a change in the splicing pattern of the neuropsin gene, creating a new splicing site and a longer protein. Introducing this mutation into chimpanzee DNA resulted in the creation of type II neuropsin. “Hence, the human-specific mutation is not only necessary but also sufficient in creating the novel splice form,” the authors state.”

Human version of neuropsin is longer, which alters the efficacy of its function. I don’t know how, but obviously must do something better. Other conclusions have been made, but none are as significant as the ones I’ve bolded in the above quote.

I’ve decided to do some of my own research on neuropsin, to see what we know of it… where it’s located, what sorta promoters it has, etc. So I fired up NCBI’s GenBank and put in ‘neuropsin‘. Sadly, no current genomic information on the gene is up there yet. Some interesting nucleotide and protein sequences are there, as well as a cool 3d model of the protein.

Most importantly, neuropsin has been identified to function as “A Serine Protease Expressed In The Limbic System Of Mouse Brain.” A protease is an enzyme that basically breaks up things, and since serine prefixes it… neruposin functions as a breakdown component of serine, a hydrophilic amino acid that is a constituent of most proteins. Currently three human diseases are attributed to the malfunction of this enzyme, which I wonder what implications that has as far as symptoms? Reduced cognitive functions?

I also wonder why humans have this alternative modified protein in our brains and not chimpanzees, now that I know the function? Does having a second type of neuropsin allow for us to process serine more effectively, ultimately facilitating some of our cognitive differences? I know I already asked that but it is something I don’t fully understand. That’s something the authors advocate to be studied in the future, to identify,

“the biological function of type II neuropsin in humans, as the extra 45 amino acids in this form may cause protein structural and functional changes. They note that in order to understand the genetic basis that underlies the traits that set humans apart from nonhuman primates, recent studies have focused on identifying genes that have been positively selected during human evolution. They conclude, “The present results underscore the potential importance of the creation of novel splicing forms in the central nervous system in the emergence of human cognition.”

Very interesting news, none the less. Definately one of those genes to keep in the back of your head, no pun intended… really. If you like this sorta stuff, please keep in touch with me, and also check out John Hawks who published out an issue of the neuroscience blog carnival, Encephalon. I wish this post coulda made today’s issue, but I just got word of it midday! Maybe next time.

P.S. This article on ‘stalled human evolution‘ maybe also of interest. I haven’t read it yet, but with a headline like that, its bound to have some controversial stuff in it.

In a effort to help save orangutans, Malaysian authorities are proposing a fund of 200 million ringgit (approx. 59 million US dollars) to rebuild the Ulu Segama-Malua forest in eastern Sabah state on Borneo island. The proposal covers work on 4,000 hectares of logged forests and 1,000 hectares of degraded forests (approx. total 12,355 acres).

It’s an exciting step in conservation efforts given the recent claims that orangutans could become extinct in the next 50 years without intervention.

The proposed plan is anticipated to be ready by late 2007.

Since mouse lemurs made our blog a couple times last year, and that one of our readers recently commented on how she was doing a report on them, I figured you may want to see photo of a newly described species of mouse lemur: Goodman’s mouse lemur, Microcebus lehilahytsara.

Check out a photo of one of these critters to the right.

I do not have an official press release or scientific publication. Actually, I’ve picked this up from a fellow blogger,

“The German primatologists chose this name to honor Steve Goodman, scientist with The Field Museum in Chicago and WWF in Madagascar. “Goodman’s field research in all remote parts of Madagascar has contributed enormously to our knowledge about the diversity of Madagascar’s unique and threatened fauna and flora,” Kappeler says.

“It is truly an honor to have such an animal named after me,” Goodman says, “but this is really a joint tribute to all of the scientists and students who have taken part in our multidisciplinary surveys over the past 16 years.”

It has a long bushy tail, relatively small ears and large testes, which are suggestive of a promiscuous mating system.”

I don’t get the comment on the feature correlation and the mating system. But it’s a cool announcement, none-the-less.