Defying Darwin by Katharina Kropshofer
W
ithin biological science, there is a man who represents what Mozart is to classical musicians, what Jamie Oliver is to amateur cooks and what Lena Dunham is to a new generation of feminists. The man’s name? Charles Darwin. Questioning him and his established theories is quite possibly one of the biggest taboos in science. Words of critique are often associated with creationism, an evolutionist’s sworn enemy.
Darwin was a strong defender of the thesis that competition between individuals allowed only the winners to survive and reproduce. Conversely, scholars like Wallace believed that it was adaptations to environmental pressures that guaranteed species variety. This idea links to the theories of Jean-Baptiste Lamarck, whose theories are normally considered incompatible with Darwin’s and therefore rejected. He stated that the influence of circumstances (or “L’influence des circonstances”) leads to animals adapting to their environment during their own lifetime.
Cooperate, creatures!
Moving away from molecular insights, our social behaviour can provide us with some more examples that throw into question the classical Darwinist approach. Could cooperation be the key to understanding how species evolve?
However, as the 158th birthday of On the Origin of Species approaches, it’s time to revisit this hugely influential book within the context of the social changes and scientific developments that have transpired since its publication. This assessment demands a critical review of Darwin’s legacy. Is it taboo to say that Darwin has left us with many gaps to fill?
Martin Nowak, mathematician and biologist at the University of Harvard, is using game theory – often applied to economics – to produce mathematical models about conflict, cooperation and zero-sum games. They can be applied to the way organisms interact on different levels, like single cells cooperating to form multicellular organisms. In cooperation between species and individuals, this follows the logic of “tit for tat”, or reciprocity.
In 1831, on board the famous HMS Beagle, Darwin came up with his key theories. However, he waited another twenty years to publish them, and they may never have been published at all, if it weren’t for the naturalist Alfred Russel Wallace. Wallace sent Darwin a letter suggesting that natural selection could lead to species change over time, an idea almost identical to Darwin’s. It was this unexpected letter that led Darwin to quickly publish his findings, catapulting him to success. What made him wait? Was it fear of the established and popular views of the Church? Or was it clear to him that his theories were still missing s omething?
Lamarckism in the 21st Century
“In the distant future I see open fields for far more important researches,” Darwin wrote. He was apparently well aware of the potential to expand his research, but also of the flaws of his theory. He didn’t know a lot about the variations and mechanisms for change between generations. Instead, it was the Austrian monk Gregor Mendel who established the basic rules of inheritance, considered valid at the time.
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I, Science
Epigenetics studies the non-genetic mechanisms (notably a chemical process known as methylation) capable of altering living DNA. The genetic changes can then be stored and passed onto the following generations. It means that malnourished rats can give birth to undersized pups by passing on some acquired traits. It also means that elements outside the genome can regulate how genes are expressed, activated and de-activated. This is especially interesting when it comes to psychology, and the effects of traumatic experiences. Researchers from Emory University have conditioned male mice to be afraid of a specific smell. The surprising thing? Their offspring responded to the scent in the same way. The only way this response could have been transmitted is via epigenetic changes in the mice’s sperm.
Lamarck’s theory is known as soft inheritance and is regaining popularity among the scientific community today. Though Lamarck is often portrayed as an ‘old fogey’, his ideas were progressive: “On our planet, all objects are subject to continual and inevitable changes (…) They take place at a variable rate according to the nature, condition, or situation of the objects involved.” For a long time it didn’t seem like variation in phenotype (the non-genetic makeup of organisms) could lead to heritable change in genotype, but the approach of epigenetics makes this notion very plausible.
According to Nowak’s research, some organisms will even relinquish their own benefits to ensure the success of a companion. In terms of fitness, this means indulging our counterpart and so could be considered to oppose ‘natural selection’. Although Nowak himself is a controversial figure in the field of Evolutionary Biology - not least because he is a staunch christian - but he also proposed interesting mechanisms by which cooperation may become favoured in evolution over being selfish. He draws on research of reciprocity to suggest a mechanism of ‘reputation’: an organism may help another due to the expected compensation by someone else. ‘Cooperation, not competition’: a possible extension to Darwin’s theories of inheritance and evolution. Also generally wise words to live by.
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