Scientists say they’ve finally proven a Charles Darwin theory that says the small animal groups that make up a species are critical to the evolution and survival of mammals
- Research sheds light on the role of subspecies according to Charles Darwin
- It suggests that subspecies are indeed a critical step in evolution
- Scientist also say that it could help future conservation efforts
Scientists may have finally proven a theory first outlined by evolutionary biologist, Charles Darwin.
According to research published in the Proceedings of the Royal Society B by Laura van Holstein, a Ph.D. student in Biological Anthropology at St John’s College, University of Cambridge, subspecies may play a much larger role in mammalian evolution than previously thought.
Specifically, the researchers found that subspecies were the beginning stages of speciation – the formation of a new species – and may therefore play a critical role in the continued evolution and survival of mammals.
The anthropologist studied Darwin’s hypothesis by looking at data gathered by scientists throughout hundreds of years, dating back long before Darwin famously visited the Galapagos Islands.
Charles Darwin (pictured) helped pioneer much of what is now modern day evolutionary theory. New research suggests that some of his theories on subspecies were right
‘In Chapter 3 of On the Origin of Species Darwin said animal lineages with more species should also contain more ‘varieties’.
Subspecies is the modern definition. My research investigating the relationship between species and the variety of subspecies proves that subspecies play a critical role in long-term evolutionary dynamics and in future evolution of species,’ said van Holstein in a statement.
‘And they always have, which is what Darwin suspected when he was defining what a species actually was.’
The analysis also also casts light on how geography influences evolution happens differently in land mammals (terrestrial) compared to sea mammals and bats (non-terrestrial – namely their habitats and differences in their ability to roam freely.
‘We found the evolutionary relationship between mammalian species and subspecies differs depending on their habitat, van Holsten said in a statement.
‘Subspecies form, diversify and increase in number in a different way in non-terrestrial and terrestrial habitats, and this in turn affects how subspecies may eventually become species.’
Researchers say that if a natural barrier such as a mountain gets in the way of a particular species it can separate animal groups and prompt them to diverge from their species on their own evolutionary path.
However, ‘flying and marine mammals—such as bats and dolphins—have fewer physical barriers in their environment,’ says van Holsten.
“The Origins of Species” (pictured) was written by Darwin and published in 1859. The tex is still studied by biologists today
In addition to illuminating Darwin’s research, the findings also may help cast light on the future of current species and the impact of humans on their evolution.
It could also help conservationists figure out where to allocate their efforts in order to ensure the best chance of survival.
‘Evolutionary models could now use these findings to anticipate how human activity like logging and deforestation will affect evolution in the future by disrupting the habitat of species,’ van Holsten said.
‘The impact on animals will vary depending on how their ability to roam, or range, is affected. Animal subspecies tend to be ignored, but they play a pivotal role in longer term future evolution dynamics.’
WHO WAS CHARLES DARWIN?
Charles Darwin (1809-1882)
Charles Robert Darwin was born in Shrewsbury, Shropshire, the fifth of six children of wealthy and well-connected parents.
One of his grandfathers was Erasmus Darwin, a doctor whose book ‘Zoonomia’ had set out a radical and highly controversial idea, that one species could ‘transmute’ into another. Transmutation is what evolution was then known as.
In 1825, Charles Darwin studied at Edinburgh University, one of the best places in Britain to study science.
It attracted free thinkers with radical opinions including, among other things, theories of transmutation.
Darwin trained to be a clergyman in Cambridge in 1827 after abandoning his plans to become a doctor, but continued his passion for biology.
In 1831, Charles’ tutor recommended he go on a voyage around the world on HMS Beagle.
Over the next five years Darwin travelled five continents collecting samples and specimens while investigating the local geology.
With long periods of nothing to do but reflect and read, he studied Charles Lyell’s Principles of Geology, which had a profound impact.
The trip also began a life of illness after he suffered terrible sea sickness.
In 1835, HMS Beagle made a five-week stop at the Galapágos Islands, 600 miles off the coast of Ecuador.
There, he studied finches, tortoises and mockingbirds although not in enough detail to come to any great conclusions.
But he was beginning to accumulate observations which were fast building up.
On returning home in 1838, Darwin showed his specimens to fellow biologists and began writing up his travels.
It was then that he started to see how ‘transmutation’ happened.
He found that animals more suited to their environment survived longer and have more young.
Evolution occurred by a process he called ‘Natural Selection’ although he struggled with the idea because it contradicted his Christian world view.
Having experienced his grandfather being ostracised for his theories, Darwin collected more evidence, while documenting his travels, until 1851.
He decided to publish his theory after he began to suffer long bouts of sickness.
Some historians suggest that he had contracted a tropical illness while others felt that his symptoms were largely psychosomatic, brought on by anxiety.
In 1858, Darwin received a letter from Alfred Russel Wallace, an admirer of Darwin’s from reading about his Beagle Voyage.
Darwin drew fierce criticism from the Church and some of the press. Many people were shaken by the book’s key implication that human beings descended from apes, although Darwin only hinted at it
Wallace arrived at the theory of natural selection independently and wanted Darwin’s advice on how to publish.
In 1858, Darwin finally went public giving Wallace some credit for the idea.
Darwin’s ideas were presented to Britain’s leading Natural History body, the Linnean Society.
In 1859, he published his theory on evolution. It would become one of the most important books ever written.
Darwin drew fierce criticism from the Church and some of the press. Many people were shaken by the book’s key implication that human beings descended from apes, although Darwin only hinted at it.
In 1862, Darwin wrote a warning about close relatives having children, he was already worried about his own marriage, having married his cousin Emma and lost three of their children and nursed others through illness.
Darwin knew that orchids were less healthy when they self-fertilised and worried that inbreeding within his own family may have caused problems.
He worked until his death in 1882. Realising that his powers were fading, he described his local graveyard as ‘the sweetest place on Earth’.
He was buried at Westminster Abbey.
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