Afarensis is a 3.5-2.8 million year old hominin from the Kada Hadar member of the Hadar formation in the Middle Awash, Ethiopia. He is approximately 41 inches tall, weighs approximately 60 pounds and has a cranial capacity of a whopping 410 cc (approximately). Afarensis is currently considered to be transitional between apes and humans and displays some traits of both. Since he spends a lot of time on the couch watching monster movies, some observers question whether he is an obligate biped (although no one has observed him climbing a tree). He also has a blog called 
Legend has it that when Darwin was puzzled by a particularly difficult problem he would spend time on the Sandwalk. The difficulty of the problem was measured by the number of stones he would cast on a pile each time round. Originally, the Sandwalk was owned by SIr John Lubbock, but Darwin loved it so much he traded some property to Lubbock for it. Which is all fine and dandy for theoretical work, but for experimental work Darwin needed more. A knowledge of comparative anatomy would come in handy (Darwin was quite good in comparative anatomy, as his monographs on Cirripedia demonstrate. This knowledge would come in handy when Darwin was trying to solve a particulary vexing Orchid problem - but that is the subject of next weeks post). Equally important for an experimental biologist is a knowledge of the equipment needed to make a contribution.
To the left is a picture of one of Darwin's microscopes. It is currently housed in the Whipple Museum. The Whipple Museum has this to say about it:
The 1/8" object glass was an impressive lens, even by modern standards. It allowed Darwin to achieve a maximum magnification of over 1300 times. The resolution and image quality at this magnification would have been poor, however, and from the measurements he made it can be estimated that Darwin carried out most of his high-power work at magnifications up to about 850 times. [emphasis mine - afarensis]
I have bolded the sentence above because it demonstrates another important skill for someone performing experiments. Namely, a knowledge of the strengths and weaknesses of the equipment being used.
The Whipple Museum article continues:
Darwin had strict ideas about the use of the microscope. He thought that using high powers without using low powers was "injurous to natural philosophy". Whilst this does not necessarily mean that he lacked faith in higher power microscopes, it does show that he was aware of the mistakes that could be made by examining objects without the visual frame of reference provided by low powers.This shows Darwin to be a skilled and sophisticated microscopist. In combination with his renowned talent for slide preparation, Darwin can be understood as a more practical man of science, using instruments and undertaking important experiments.
This last bit surprised me. I was unaware of Darwin's reputation of being a talented in preparing slides (which is harder than it sounds, as anyone who has had freshman biology can testify). After Darwin's death many of the slides he prepared during the course of his work on Cirripedia were donated to the The University Museum of Zoology Cambridge The microscope pictured next may not have been Darwin's, but it is similar to the one he used on the Beagle.
Comments
From what I've read, Darwin was very particular about his instruments, always wanting to buy the best and upgrading regularly. It would take quite a degree of skill to dissect the small barnacle parts etc that he worked on. I have a hard enough time threading a needle.
Posted by: King Aardvark | March 29, 2007 11:49 AM