Underblog.co.uk

I feel I’ve been fairly lax about updating lately, but I’ve got something here that should make up for the lack of posts over the past week or so: probably the most significant piece of monkeynews yet to feature here at underblog. Before I get started though, I should probably mention that underblog appears to have a rival in the monkeynews blog market. Go and check out A Relative Path’s story on China’s recognition of the sacrifices made by monkeys during the Sars virus crisis.

The locals call them “lion-killers”. They are reported to grow up to 2 metres in height and half as heavy again as the largest known chimpanzee. Their skulls are gorilla-like but their bodies more like those of chimps. Footprint casts have been taken that are longer than those of both common chimps and gorrillas. Their hair turns grey early in life, but all over, rather than just on the back like a gorilla.

These are the mysterious and unusual great apes that live in parts of the Congo basin, featured in the New Scientist. The only scientist ever to actually see them, Shelly Williams, an independent primatologist, thinks that they might be a gorrilla-chimp cross or a whole new species of great ape. If not, she says, they deserve to be catagorised as a seperate chimpanzee subspecies (of which there are currently between three and five, depending on who you listen to). If these animals were a new species, it would be a tremendous discovery, but according to the New Scientist:

not quite so outlandish as it first apears, given the ongoing wrangling over great ape classification. The bonobo, Pan paniscus, was only recognised as a seperate species in 1929, and heated debate continues about whether the orang-utans of Borneo and Sumatra are one species or two.

Behaviourally, the Congo apes have big differences from both gorillas and chimps. Unlike gorillas, who will charge down hunters when they encounter them, these beasts seem shy of people and prefer to silently slip away like a chimp would. Chimps tend to nest in trees and gorillas on the ground, although they avoid water and build a new nest every night. Lion-killer nests have been discovered on swampy ground that were obviously being reused night after night. It is thought that the heavier males sleep here, with the females and juveniles preferring nearby trees. The mysterious apes appear to live in very small groups, as opposed to the local chimp subspecies which travel in groups of 35 to 45. Unlike chimps, they peel fruit with their hands as opposed to their canines, and they use bigger tools for termite fishing than other chimps.

No-one would argue that europeans are a different species from the chinese because we eat with a knife and fork instead of chopsticks, so there is an argument that behaviour is not a very useful indicator of taxonomy in chimpanzees, because they are so culturally flexible. DNA analysis is a much more useful tool, and comparisons of the large apes’ mitochondrial DNA (extracted from faeces) with that of the local chimps suggest that they are genetically indistinguishable. This type of DNA, however, is only passed down the maternal line, so it does not rule out the possibility that they are descended from the offspring of male gorillas with female chimpanzees. Such a cross is theoritically possible, since the two species have the same number of chromosomes, but has never been observed.

My personal opinion on this type of thing is that taxonomy is not the same as, nor as important as genetic lineage. The line between species, sub-species and just a genetically dinstinct population is not always a clear one. For example, a common definition is that individuals are unable to produce fertile offspring except by pairings with members of the same species. According to this definition, if these apes are gorilla-chimp hybrids then chimpanzees and gorillas should actually be classed as the same species. Whether just very weird chimps, a completely new species or anything in between, these fantastic apes clearly merit further study.

This entry was posted on Monday, October 11th, 2004 at 22:51 and is filed under Monkeynews. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.