Tina Negus, a teenage girl from the United Kingdom, was on vacation with her family
in the Charnwood Forest in 1956 when she
observed
a strange footprint on an overhanging rock wall.
It resembled a fern. However, as a young geologist, Negus recognized that
these 600 million year old rocks were too ancient to support such a plant.
According to the fossil record, the first complex species of flora would not
arise for at least another sixty million years after the Cambrian
boom.
The 'explosion's' rapid burst of biodiversity, also referred to as the
biological big bang, was the
most perplexing challenge
confronting Charles Darwin's theory of evolution. Darwin could not find a
satisfying response to two nagging concerns in his classic book, On the
Origin of Species: Where did all this diversity of life suddenly emerge
from? And how did it evolve so fast?
When Negus returned to school, she presented her geography instructor a
pencil rubbing of her 'fern' find. But he wasn't convinced.
Three adolescent guys were playing along the same rock face a year later,
in 1957, when they spotted the identical fossil. Roger Mason, fifteen,
took a pencil rubbing of the imprint so that his father could pass it on to a local university instructor.
It took some persuading, but after examining the fossil for himself,
geologist Trevor Ford confirmed that it was, in fact, a Precambrian relic of
a plant that formerly existed on the seafloor.
Mason was named after the tubular, frond-shaped lifeform
Charnia masoni.
Paleontologists all across the world were now able to look at old fossils
with fresh eyes with the discovery of Charnia and improved dating
techniques. Lifeforms that were
thought to be Cambrian were now discovered to be considerably older.
A few months after Ford published his results, for example, scientists in
Australia announced the discovery of another Precambrian Charnia
frond.
The Charnwood fossil was certainly not an accident. It was everything
Darwin and his successors had been looking for in terms of proof of
sophisticated life prior to the Cambrian explosion.
While the finding was generating quite a commotion in the scientific
community, Negus was completely ignorant of the impact her unusual fern
fossil was having. It wasn't until 1961 that
she discovered
what had happened to her fossil and how significant it had been.
In 2004, she saw an interview with Roger Mason in which he shared his tale
about discovering the fossil. He responded right away when she sought out.
Negus was invited to the 50th anniversary of the plant's discovery in 2007,
when she was finally recognized as a co-discoverer.
It turns out that, like Negus, numerous other people had spotted similar
fossils in the past, but had been overlooked by the scientific
establishment.
Some naturalists, for example, found macrofossils in Charnwood Forest in
1848 and classified them as probable Precambrian living forms.
This suggests that the solution to Darwin's conundrum existed before he
publicly expressed his uncertainty in 1859.
Precambrian living forms have been discovered in England, Australia, North
America, Greenland, South Africa, sections of Asia, and Russia.
It is now obvious that sophisticated plants existed prior to the Cambrian
explosion. Even yet, it's still unclear why variety expanded more than 500
million years ago.
It may be prudent to keep fresh Precambrian and Cambrian findings in mind
in the future.
Clearly, children's innocent eyes can perceive possibilities that even the
most trained scientists cannot.
