Genes, Phylogeny, and Orangutans

Jeffrey H. Schwartz is well known to talk.origins veterans because we discussed his book (Sudden Origins: Fossils, Genes, and the Emergence of Species) back in 1999. Schwartz tried to make the case for a "groundbreaking and radical new theory of evolution." This "theory" was based on the idea that new species spring into existence very quickly when a mutation in a homeobox (HOZ) gene arises in a population. It's a "theory" of saltation but it's based on such a flawed understanding of genetics that you really have to read to book to see just how bad it is. Sudden Origins is a leading candidate for the worst science book ever published.

In case you want to see a shorter version, the basic idea is explained in Schwartz (1999).

Over the years, Schwartz has published many other ideas that are controversial. Lately he has been pushing the concept that molecular phylogenies are unreliable. In part this is because he is opposed to gradual change as documented in the record of the genes. He thinks that real evolution takes place when alterations of regulatory genes result in major new phenotypes. Thus, the best way to discover the history of life is to examine anatomical homologies and differences.

But part of the problem lies in Jeffrey Schwartz's idiosyncratic understanding of genetics and molecular biology. When you put these together, this is what you get in Schwartz (2009).

This having been said, systematics and evolutionary biology need not remain estranged. Developmental biology increasingly makes clear that organismal change (and by extension, evolution), is not how it was imagined when the synthesis emerged (see reviews in Schwartz 1999, 2009b; Maresca and Schwartz 2006). Further, because of the interrelation between, e.g., the physical properties of cells, signaling pathways, epigenetic effects and development and consequently the origination of form, the false dichotomy of ‘‘molecules versus morphology’’ that resulted in the 1980s from the dethroning of morphology by the hegemony of molecular analyses is no longer tenable (Schwartz 2009a). Indeed, the undeniable hierarchical continuum from the molecular through the morphological, firmly centralizes morphology (as understood via development) in systematic endeavors (Schwartz 2009a).

Grahan and Schwartz (2009) have just published a paper in which they claim that orangutans are more closely related to humans that are chimpanzees. According to them, the molecular data is not reliable. They claim that detailed morphological comparisons show that orangutans are our closest ancestor.

John Hawks asks the question "Are orangutans our closest living relatives?" and he comes up with the best possible answer to scientists with a well-known history of promoting "unusual" positions on evolution.

It's a lesson that New Scientist should have learned. They devote several pages to the Grahan and Schwartz paper thereby giving it much more publicity than it deserves [Could the orang-utan be our closest relative?].¹ The article is written by Graham Lawton who you might remember from the "Tree of Life" episode [see: Explaining the New Scientist Cover]. The editors of New Scientist knew full well that their decision would be controversial so they took a proactive position by writing a short editorial [In praise of scientific heresy ].

If its claims are so outlandish, should the research even have been published? Some scientists would clearly have preferred it if the paper had never seen the light of day, and question the judgement of the journal.

That is territory we should tread with care. Ideas that mainstream opinion "knows" to be wrong occasionally turn out to be right. The insights of Galileo, Stan Prusiner - who discovered prions - and many others were once denounced as heresy. And even those that are wrong can be valuable.

Science proceeds by questioning its own assumptions and regarding every "fact" as provisional, so alternative hypotheses should be given an airing, if only to reaffirm the strength of the orthodoxy. Science that pulls up the drawbridge on new ideas risks becoming sterile. The journal recognised that and should be applauded for its decision to disseminate this challenging paper.

There's some truth here, but only some. You can't use Stanley Prusiner as an excuse to publish every crazy idea that comes along. Some ideas really are crazy—they are not revolutions in disguise. The plain fact is that Jeffrey H. Schwartz has already had his chance to make his case and he has not been successful. How many chances does he get before we draw the obvious conclusion?

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1. The article was two pages long and the editorial was much less than one page. This may not qualify as "several" pages by some definitions.

[Photo Credit: Daily Mail]

Grehan, J.R. and Schwartz, J.H. (2009) Evolution of the second orangutan: phylogeny and biogeography of hominid origins. Journal of Biogeography, published online June 22. 2009. [doi:10.1111/j.1365-2699.2009.02141.x]

Schwartz, J.H. (1999) Homeobox genes, fossils, and the origin of species. Anat Rec. 15:15-31. [PubMed]

Schwartz, J.H. (2009) Reflections on Systematics and Phylogenetic
Reconstruction. Acta Biotheor 57:295–305 [doi: 10.1007/s10441-009-9078-9]