Discussion and brief analysis of the New Scientist article ‘Darwin Was Wrong’.

January 29, 2009

New Scientist published an interesting article recently in its January 2009 issue. It can be found online here: http://www.newscientist.com/article/mg20126921.600-why-darwin-was-wrong-about-the-tree-of-life.html?full=true

The front cover of the issue stated in headline form ‘Darwin Was Wrong’. The article went on to discuss how Darwin’s tree of life was actually incorrect, and how some assumptions underlying relationships between organisms weren’t quite as simple as they seemed. Let us discuss the article itself, but before doing so, I would like to point out that New Scientist have, after the publication of its controversial front cover, acted irresponsibly with the unfair statement made, purely to sensationalise its story and attract more readers. The magazine is read by many anti-evolutionist religious fundamentalists, and an unfair headline which hasn’t been more accurate will stick in the minds of these individuals, rather than the content of the article itself.  These people will assume that the whole theory of evolution is in fact wrong, which of course has already been stated by many creationist and intelligent design websites following the publication of this issue. New Scientist themselves acknowledged this in an editorial post:

“None of this should give succour to creationists, whose blinkered universe is doubtless already buzzing with the news that “New Scientist has announced Darwin was wrong”. Expect to find excerpts ripped out of context and presented as evidence that biologists are deserting the theory of evolution en masse.”

A better title would have been ‘What Darwin didn’t know about the tree of life’. Coming onto the article and it’s points. Darwin thought the relationships between all species, living and extinct, fitted onto a tree-like pattern. He assumed that all species descended by a branching process from earlier ancestors, which themselves had descended by a branching process, until you reached the very first ancestor of all life forms that have ever lived. He described this tree-like idea as the tree of life. However, Darwin based this idea upon the forms of life that he had studied and could observe at the time. These consisted of animals and plants, which are multicellular forms of life. And since nothing at the time was known about the inheritance of traits, he also postulated that traits were passed down from previous generations to the next, in one, vertical direction.

Those assumptions are now known to be incorrect, however one must sympathise with Darwin, as he lived at a time where methods for detecting and analysing genes were far from being available. The article itself points out why these assumptions were incorrect. Firstly, it has been shown in prokaryotes (which are cells without nuclei, e.g. bacteria) that genes can be transferred between organisms which are not ancestors/descendants of one another, or between different species (a process known as horizontal gene transfer, HGT), in addition to the usual transmission via cell division, from parent to daughter cells. This occurs fairly regularly in prokaryotes, so genes can be ‘shuffled’ within a population. Thus, trees constructed based on DNA sequences may be different to trees constructed using other data based on vertical inheritance. There is also evidence supporting this phenomenon occuring in eukaryotes (cells with nuclei), including plants and animals (some genes have even been found to be a result of HGT in humans and elephants).

Secondly, the assumption that speciation occurs exclusively in branches has also been shown to have many exceptions. For instance, rather than one entity branching out to form two or more entitities, there are examples in nature where two lineages can breed together to form a hybrid species. This is true for many prokaryotic lineages, as well as many eukaryotes; for example, it is thought that a eukaryote once engulfed a prokaryotic bacterial species, and this lead to the lineage of cells containing mitochondria (the energy producing machinery in cells), which are ancient remnants of those bacteria. Also, it is accepted that eukaryotes themselves were formed by a fusion of two prokaryotes. Thus, this merging of two lineages to give one is the opposite to the branching process.

Finally, Darwin’s assumption of all life forms being descended from one single cell may also be incorrect, due to the nature of of the processes described above; it is more likely that there was an ancestral population of cells rather than a single ancestral cell. However, the individual ancestor to all of life may be a single replicating entity that gave rise to other replicating entities, of which only DNA and RNA survive today, as currently known. The carriers of these replicators are therefore all related, and thus Darwin’s idea of a universal common ancestor for all of life may still hold.

To conclude, Darwin made certain assumptions about the tree of life (i.e. it’s applicability to all living organisms) which have shown to be incorrect, however we know that it still pretty much applies to most animals, and so it is unfair to have labelled him bluntly as ‘wrong’, since animals were what he dealt with mainly. The relationships between all forms of life will look different to a universal tree; more like a web network. But this web too will provide the roots of a tree that is applicable to individual lineages of eukaryotes, including animals.

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5 Responses to “Discussion and brief analysis of the New Scientist article ‘Darwin Was Wrong’.”

  1. kkob said

    For a start, New Scientist isn’t a scientific journal, it’s not Nature or Science, or even Trends in Biochemistry. It’s a popular science magazine, it’s main goal is to make science easily accessible to everyday people, and to do so in an entertaining way. A front cover adorned with the headline “Darwinists were incorrect” would put off many of the people who the magazine is aimed at. “Darwin was wrong” is blunt and to the point. Much like a “Newton was wrong”. And what’s unique about these two scientists is that they have a strong orthodox following, which resists change. So the use of Darwin is more of an umbrella term for Darwinists, especially those who were insistent that the tree of life could be completed accurately. Now, after that, I can carry on reading 🙂

  2. dawkinsrottweiler said

    The point about NS being a magazine I accept. The point about Darwin being an umbrella term for Darwinists I don’t, and it has not been used in that context in this article either. The article is directly aimed at Darwin’s assertion for the ToL being universal. It only mentions Darwinists later on in the article when discussing the applicability of the tree to all species of life.

  3. kkob said

    Exactly, they say in the opening few paragraphs why Darwin was wrong, and then later tackles what the new understanding is. I’ve said my thoughts, and after reading the rest of the post they haven’t changed. NS were fair in their title, and then the subtitle to give clarity “cutting down the tree of life”. If it sold more issues, and helped spread science I’m happy. It hasn’t done any harm, and it doesn’t get widely circulated in America I think.

  4. dawkinsrottweiler said

    Wrong. It has done much harm, as many creationist websites have already taken the title at face value, and have promoted more ignorance througout the religious community which could have been avoided.

  5. David said

    I think it’s disgraceful. Whilst Karl has made a really valid comment about it being a magazine rather than a scientific meta-analysis of detailed theory- the majority of people in the world, when confronted with it at face-value would assume (reasonably!) the opposite. It was blatantly irresponsible to publish a magazine with such nuances associated with it with “Darwin was Wrong” on the front cover. Darwin wasn’t wrong about evolution, he was mistaken on a few of the finer points, which I will allow him to be given it was 150 years ago! He didn’t even know what the genome was, let alone some of the more difficult concepts of modern genetics and inheritance patterns.

    Creationists should know that they are wrong, and how wrong they really are. I have all the time in the world to debate the finer points of faith (vs) science, even to the most ardent of followers. The one thing I cannot abide, is something that has, point-blank, been made redundant. The world is not 6000 years old, Adam and Eve did not start off the human race and we did evolve from more primative primates.

    This cover-story in New Scientist does nothing to advance science and its role in education. It saddens me greatly as an evolutionary biologist and medic that someone was idiotic enough to implement what is tantamount to negligence, in writing on the cover of one of the most widely publicised magazines concerning popular science.

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