When Darwin was developing his theory, the age of the earth was not well understood. Darwin himself advocated a 400 million year or more age for the earth, which he considered to be required for the new species to evolve. This requirement became particularly evident when William Thomson (later Lord Kelvin), only a few years after Darwin had published his book on evolution, argued that the earth could be no older than 100 million years. Thomson later revised that figure downward to as little as 20-40 million years.
The 100 million years that Thomson allowed was not nearly long enough for evolution to work. “Thomson’s views of the recent age of the world,” wrote Darwin, “have been for some time one of my sorest troubles.” As Cherry Lewis of the University of Bristol has explained, “The age of the Earth was hugely important for people like Darwin who needed enormous amounts of time in which evolution could occur. As Thomas Huxley, Darwin’s chief advocate said: ‘Biology takes its time from Geology’.”
Darwin and Huxley worked to overthrow Thomson’s time restriction. Darwin enlisted his son George, a mathematician at Cambridge, to rework Thomson’s calculations. Eventually, around the turn of the century, geology rejected Thomson’s arguments. The usual reason given for this is that Thomson was unaware of radioactivity as a source of thermal energy, though it seems the story is more complicated than this.
In any case, geology soon extended the age of the earth into the billions of years, and evolution’s requirement for long time periods, so it seemed, was fulfilled.
It is now known, however, that evolution has nowhere near the eons of time it requires. Indeed, the time windows available are even less than those allowed by William Thomson, which themselves were unacceptable to the evolutionists. This falsification of evolution’s expectation does not derive from the age of the earth, but rather from the fossil record. We now know that, even with billions of years of earth history, the major events in the fossil record take place in time windows that are no longer than a few tens of millions of years or even less.
The professor recounts the story of Darwin versus Thomson and naively thinks he has another victory for evolution when in fact unbeknownst to him he is revealing yet another problem:
Kelvin ultimately settled on a more narrow range of 20 - 40 million years. Regardless, Kelvin believed this was too short for evolution to explain the diversity of life on Earth. You know what, Charles Darwin concurred. Darwin knew that his theory requires that the Earth to be extremely old. In the first edition of Origin of Species, Darwin argued that the time necessary for erosion to form the Weald in England is at least 300 million years (But we would also need to factor in the time to deposit all the material to be eroded among other things, which brings us to an age of billions of years). However, based on Kelvin’s calculations, Darwin removed these arguments from later editions of Origin of Speices and referred to the problem (or Kelvin) as an ‘odious spectre’ in letters. To be clear here, both scientists had data to back up their claims, but Darwin was quite cautious in his claims.
The interesting point is that Kelvin was flat out wrong. Based on what was known at the time, Kelvin’s approach was defensible. However, this was before we knew about radioactivity. The Earth did cool, but it is not simply a loss of heat issue, as assumed by Kelvin. Radioactive decay generates heat, and there is a lot of radioactive decay within the planet. Kelvin thought the Earth’s core was solid and that all heat transfer was by conduction (wrong on both counts).
By making a number of assumptions, which were defensible at the time, Lord Kelvin mathematically derived an age of the Earth that undercut the Theory of Evolution as well as most of geology. However, data was already in existence that suggested the Earth was much older than the age calculated by Kelvin. As more knowledge was gained, it became clear that Kelvin’s assumptions were invalid and thus his calculation wrong. Turns out the Earth is ~4.5 billion years old, which is plenty of time for geological formations to arise and giraffes to evolve.
But of course this is all wrong. If evolution is true we must believe it performs its uncanny miracles much faster than 4.5 billion years. The creation of life, the origin of fantastically complex cells, the creation of biology’s myriad designs, new species arising, and yes giraffes could not have evolved over billions of years. They could not have evolved even over hundreds of millions of years. It all must have happened much faster, in what are sometimes referred to as evolution’s “Big Bangs” where evolution leaves the equilibrium and for some reason becomes punctuated.
Of course none of this is a problem for evolutionists. As usual, contradictory evidence is handled with just another just-so story. “Oh,” they conclude, “evolution must have occurred rapidly for some reason.” It’s that easy because when you’re certain you’re right, then evidence doesn’t matter.
Religion drives science, and it matters.