Wallace's Big Adventures:
Alfred Russel Wallace made two long expeditions. His first was a collecting trip to the Amazon with Henry Walter Bates. The second was his trip to the Malay Archelepago. His writings clearly show the development of his thoughts.
Africa: the Amazon. Sailed from Liverpool on April 20, 1848, returned July 20, 1852.
Few images are available from this time as nearly everything was lost at sea. A few of Wallace's journals remain.
- This trip was instrumental in honing Wallace's skills as a naturalist and his development as a biological theorist as is shown in the following passages from A Narrative:
- "The weather was not so hot, the people were not so peculiar, the vegetation was not so striking, as the glowing picture I had conjured up in my imagination, and had been brooding over during the tedium of a sea-voyage..... during the first week of our residence in Para, though constantly in the forest in the neighborhood of the city, I did not see a single humming-bird, parrot, or monkey" (Narratives, p. 3-4). Wallace clearly is moving from the role of skilled collector to that of an observer of the culture of primitive peoples and their interactions with the natural world.
- "Can it be right to keep a number of our fellow creatures in a state of adult infancy, of unthinking childhood? It is the responsibililty and self-dependence of manhood that calls forth the highest powers and energies within our race. It is the struggle for existence, the 'battle of life', which exercises the moral faculties and calls forth the latent sparks of genius. The hope of gain, the love of power, the desire of fame and appreciation, excite to noble deeds and the call into action all those faculties which are the distinctive attributes of man" (Narratives p. 8).
- The study of geographical distribution of plants and animals clearly began to interest Wallace. Most works at this time were simple descriptions of distribution data and gave no explanation for the distribution beyond an attribution to a Creator. (Fichman) Advances in geological knowledge at this time were seriously challenging biblical interpretations of natural history.
- In Narrative, Wallace wrote, "countries possessing a climate and soil very similar, may differ almost entirely in their productions. Thus Europe and North America have scarcely an animal in common in the temperate zone; and South America contrasts equally with the opposite coast of Africa; while Australia differs almost entirely in its productions from districts under the same parallel of latitude in South Africa and South America" (p. 326).
- Wallace documented several instances of rivers as a line of contrast between two closely related species (Narrative, p 328-329):
- Butterfly species Callithea sapphira and C. Leprieuri are restricted to opposite banks along the same expanse of the Amazon River
- Three species of Psophia ( Trumpeters) are separated by river boundaries, with Psophia viridis (Green-Winged) on the south bank east of the Madeira River; P. leucoptera (White-winged) is on the south bank but west of the Madeira River; P. crepitans (Common) is not found at all on the south bank.
- A few species on monkeys follow the same pattern as the Trumpeters.
- Noting these patterns, Wallace thereafter insisted on recording the exact locale when collecting a specimen, and was apparently among the first of the naturalists to do so.
- Did the realization of the importance of the location of a collected specimen suggest to Wallace a possible explanation for the existence of apparently similar populations in different locations? It is likely he realized he was seeing the results of a population dividing, one group migrating perhaps across a barrier, with subsequent variation creating a new species. In Narrative, p. 58, he makes mention of his hypothesis that adaptation to conditions was a factor in a situation such as this.
- "In all works on Natural History, we constantly find details of the marvellous adaptation of animals to their food, their habits, and the localities in which they are found. But naturalists are now beginning to look beyond this, and see that there must be some other principle regulating the infinitely varied form of animal life. It must strike every one, that the numbers birds and insects and different groups, having scarcely any resemblance to each other, which yet feed on the same food and inhabit the same localities, cannot have been so differently constructed and adorned for that purpose alone."
Malaysia: The Malay Archipelego sailed from England in March 1854; returned 20 February 1862.
Collecting expedition in the Malay Archipelago. The Malay Archipelago includes the nations of Indonesia, Singapore, Malaysia, Brunei and Papua New Guinea.
map retrieved from http://www.sil.si.edu/Exhibitions/Underwater-Web/uw-long-and-short-00.htm on December 7, 2003.