It has long been believed that humans evolved smooth penises as a result of adopting a more monogamous reproductive strategy than their early human ancestors. Those ancestors may have used penile spines to remove the sperm of competitors when they mated with females.

Researchers, while studying another topic, stumbled upon one explanation by comparing the human and chimpanzee genomes:

They first systematically identified 510 DNA sequences missing in humans and present in chimps, finding that those sequences were almost exclusively from the non-coding regions of the genome, between genes. They then homed in on two sequences whose absence in humans they thought might be interesting — one from near the androgen receptor (AR) gene and one from near a gene involved in tumour suppression (GADD45G).

Inserting the chimpanzee sequences into mouse embryos revealed that the former sequence produced both the hard penile spines and sensory whiskers present in some animals. The latter sequence acted as a kind of brake on the growth of specific brain regions — with the removal of its function appearing to have paved the way for the evolution of the larger human brain.

Link | Photo by Flickr user lightmatter used under Creative Commons license

Jane Goodall has studied chimpanzees in Africa since 1960. She arrived in Tanganyika with no training but a lot of enthusiasm for the work ahead. Fifty years later, she is still working for the benefit of the chimpanzees she loves. National Geographic has an extensive retrospective of her life and work in the new issue, with plenty of photographs as well. Link -Thanks, Marilyn Terrell!

In addition, NatGeo has digitized and archived all the articles they’ve done on Jane Goodall and her work since 1960. Link

(Image credit: Hugo Van Lawick/National Geographic)

On two occasions witnessed, the chimps successfully deactivated the traps set for them.[...]

A typical snare, for example one made by the Manon people of Bossou, consists of a loop of iron wire connected by a vine rope to an arched stick, often a sapling.

The sapling puts tension into the rope and once an animal passes through the wire loop, the trap is sprung and the sapling pulls it tight, around the neck or leg of an animal.

Such traps cause indiscriminate damage, ensnaring any and all animals that come into contact with them.

But male Bossou chimps have worked out how to outwit the hunters and deactivate the traps.

“They seemed to know which parts of the snares are dangerous and which are not,” Mr Ohashi told the BBC.

Link via Marginal Revolution | Image: Fox

Another paper appearing in the same issue of Current Biology describes two mother chimpanzees carrying their dead infants in the Bossou colony in Guinea. Although this behavior has been observed in chimps and other primates before, the researchers, led by Dora Biro, a research fellow in the Department of Zoology at the University of Oxford, documented the carrying behavior for 68 days in one of the instances—far longer than had been previously described.

Of note, Biro’s group reported, is that documented deaths of infants in that particular colony (of which there were three) always resulted in “extended carrying,” though it is not universal that mothers carry infant corpses for weeks—or months—after death. This difference “raises questions about the potential role of observational learning in promoting chimpanzee mothers’ prolonged transport of deceased young,” Biro and colleagues wrote.

These differences in handling death might also be a part of demonstrated cultural differences among chimpanzee groups, Anderson says.

Link | Image: NIH

However, chimpanzees in this study went beyond the basic tenets of the social contract and demonstrated what could be considered the foundation of social solidarity. In 95 trials chimpanzees that received a grape were significantly more likely to refuse the high-value reward when their group mate only received a carrot (p = 0.008). Even those who benefitted from inequality recognized that the situation was unfair and they refused to enjoy their own reward if it meant someone else had to suffer.

This particular behavior was not seen in the monkeys. Did a sense of fairness evolve along with cooperation among higher primates? Link

(image credit: Flickr user Owen Booth)

Although Dr Campbell doesn’t think the chimps were “fooled” by the animations into thinking they were looking at real chimps, he explained that there was evidence that chimpanzees “process animated faces the same way they process photographs of faces”.

He said: “It’s not a real chimpanzee, but it kind of looks like a chimpanzee, and they’re responding to that.”….

In his future work, Dr Campbell would like to pin down exactly how these measurable behaviours are related to the more difficult to measure phenomenon of empathy.

“We’d like to know more about behaviours related to empathy, like consolation – when an individual does something nice to the victim of aggression,” he told BBC News.

“So we want to see if our good contagious yawners are also good consolers.”

Link via Discover Magazine

Image: U.S. Department of Health and Human Services

Researchers in the Tai National Park in West Africa found that in a study of 262 chimpanzees, male chimpanzees favored giving food to females that were in heat and ready to mate:

Gomes and co-author Christophe Boesch observed all of this while studying wild chimpanzees in the Tai National Park at the Cote d’Ivoire, West Africa. The chimp group — consisting of 49 individuals total — included five adult males and 14 adult females, which were the focus of the study published in the latest PLoS One.

The researchers recorded 262 male to female meat transfers, with the meat mostly coming from red colobus monkeys. Chimps also kill other types of monkeys, duikers and small mammals.

Gomes and Boesch collected data on matings, observing the same number — 262 — during times when females were in estrous. The scientists noted that males would share with all types of females, whether in estrous or not, although the former received preference.

“After all,” Gomes said, “males double their mating success by sharing meat with females, and this is a potentially enormous benefit.”

Link

From the Upcoming ueue, submitted by Geekazoid.

Japanese television is one of the best things in the world. Pair it with another stupidly catching internet song and you have an instant hit -especially when the video and song emphasize the wonder that is created when a chimpanzee rides on a segway.

Link via Mental Floss