observations from animals and plants

bullhorn acacia and pseudomyrmex ant

A lot of bullhorn acacia, a thorny bush that is very common in Mesoamerica, can be found in the area of Guanacaste, Costa Rica. On its leaves and stems lives the pseudomyrmex ant. One of the first rules for the jungle dweller is not to get close to these bushes, as the bites of the ants and the stinging of the thorns are both very unpleasant.
It has been known since a while that these two are in a great state of mutualism: The ants are missing a certain enzyme, so they can`t digest certain sugar types from other plants and the bullhorn acacia is the only plant providing the right type of sugar for the little animals. In exchange the ants protect the plant with their quite poisonous bites, when other animals try to eat the plant. So lots of scientists have been praising this great win/win situation and the intelligence of nature.
However, recently a couple of German scientists (not mentioned in the English references so far!) did some research on the new born baby ants and discovered a strange thing: the babies are born without a defect. The enzyme, which is missing later, is produced by the young ants and they would be able to feed on other plants as well. But as they are born on the bullhorn acacia, the first food the young ants get, is the resin from these plants. The German scientists found out that the resin contains a chemical, that blocks a certain enzyme in the ants. Without this enzyme the baby ants cannot digest the nutrients from other plants and thus they stay dependent on the bullhorn acacia for their whole life.

Bullhorn Acacia

bonobos and chimpanzees

Humans are genetically very similar to bonobos and chimpanzees:
"The gorilla must have branched off from our family tree slightly before we separated from the common and pygmy chimpanzees. The chimpanzees and bonobos, not the gorilla, are our closest relatives. Put another way, the chimpanzees' closest relative is not the gorilla but the human. Traditional taxonomy has reinforced our anthropocentric tendencies by claiming to see a fundamental dichotomy between mighty man, standing alone on high, and the lowly apes all together in the abyss of bestiality. Now future taxonomists may see things from the chimpanzees' perspective: a weak dichotomy between slightly higher apes (the three chimpanzees, including the 'human chimpanzee') and slightly lower apes (gorilla, orangutan, gibbons). The traditional distinction between 'apes' (defined as chimps, gorillas, etc.) and humans misrepresents the facts. The genetic distance (1.6%) separating us from pygmy or common chimps is barely double that separating pygmy from common chimps (0.7%). It is less than that between two species of gibbons (2.2%), or between such closely related North American bird species as red-eyed vireos and white-eyed vireos (2.9%), or between such closely related and hard-to-distinguish European bird species as willow warblers and chiffchaffs (2.6%). The remaining 98.4% of our genes are just normal chimp genes." (from Jared Diamond, The Third Chimpanzee)

Chimpanzees

For a long time bonobos were simply seen as one of various chimp subspecies. Only in the 1930s the differences in anatomy led to a distinction as a different species. Since then some major differences in social behavior of bonobos and chimps have been found.
Bonobo: Often described as more playful and joyful. Primatologist Frans de Waal states bonobos are capable of altruism, compassion, empathy, kindness, patience, and sensitivity and described "bonobo society" as a "gynecocracy". Bonobos show more sexual behavior in a greater variety of relationships. An analysis of female bonding among wild bonobos by Takeshi Furuichi stresses female sexuality and shows how female bonobos spend much more time in estrus than female chimpanzees. (Wikipedia) Some researchers say, the life of the bonobo males is far more relaxed, healthier and longer.
Chimpanzee: larger and more robust than the bonobo. They live in groups which range in size from 15 to 150 members, although individuals travel and forage in much smaller groups during the day. The species lives in a strict male-dominated hierarchy, where disputes are generally settled without the need for violence. Nearly all chimpanzee populations have been recorded using tools, modifying sticks, rocks, grass and leaves and using them for hunting and acquiring honey, termites, ants, nuts and water. Their behavior is far more violent and aggressive.
One would think that bonobos have a far better life and therefore should have an evolutionary advantage over chimps. The distribution of the two species, however, tells a different story. Bonobos are restricted to a small area south of the Congo River and north of the Kasai River in the humid forests of the Democratic Republic of Congo. According to research estimates far less bonobos exist than chimps. Chimps are spread allover Central and West Africa. They started out from north of the Congo River. At a time when the Congo River was so big that it couldn't be crossed by apes, the populations south and north of the river were separated and took a different development. The northerners became chimps, the southerners bonobos, separated only through the big stream. In the northern area the chimp population had a tight competitor for food with the orangutans, which were not present in the southern part. The chimps had to adopt a more aggressive behavior in order not to starve. Later, when the chimp population became too big to survive in their ancestral area, they started spreading to other areas. They succeeded, because they could adjust to different environments and enemies. The bonobos on the other hand never managed to survive outside their ancestral habitat.