As I understand it, theories today are not like theories of yesteryear.
Really? How about heliocentrism. That is pretty much the same as when Kepler found that planets move by elliptical orbits. Boyle's theories of gasses -- known as Boyle's Law -- is the same as it was 300 years ago.
Ever since the scientific method came out, theories have gotten a lot stronger, or have disappeared by way of exosure to being false.
Thus they were never really theories in the first place.
Ah! There's the mistake. You think theories are only the currently supported theories. No. Theories don't stop being theories because they are falsified. Geocentrism is still a theory. Proteins as the hereditary material is still a theory. Flood geology is still a theory. It was the
accepted theory until 1790. Then it was in doubt for the next 40 years as more and more falsifying evidence was found. By 1831 it was a falsified theories.
Falsified theories/hypotheses don't stop being theories. They just move from the relatively short list of currently valid hypotheses/theories to the very long lists of falsified theories.
So, it's not that it is the "only surviving theory" -- it's that there were never any other theories to contest it in the first place.
As I told you, special creation was
the accepted scientific theory until about 1850. Even Lyell was a special creationist.
In Volume II of his
Principles of Geology (1830) Lyell talked about transformation of species and specifically about Lamarck.
"Each species 'was endowed at the time of its creation, with the attributes of organization by which it is now distinguished." Only limited variations within a type have ever occurred. Each species, itself immutable, probably takes its origin from a single pair, such pairs having "been created in succession at such times and in such places as to enable them to multiply and endure for an appointed period, and occupy an appointed place on the globe." CC Gillespie, Genesis and Geology 130-131.
So there you have the competing theory: Special Creation with species remaining constant thereafter. Notice Lyell is holding out for "successive creations" over time, instead of a single universal creative event.
That is the theory that contested evolution. If you would ever read
Origin of Species, you will see that, in several places, Darwin is arguing against that theory. The data and arguments succeeded in falsifying Special Creation. That doesn't stop it from being a scientific theory. It just means it is now a
falsified theory.
In the 1982 MacLean vs Arkansas trial, the state (arguing for teaching creationism) brought Dr. Wickmarasinge to testify. Wickmarasinge, along with Dr. Fred Hoyle, had a theory called "panspermia"
"pan·sper·mi·a
panˈspərmēə/
noun
the theory that life on the earth originated from microorganisms or chemical precursors of life present in outer space and able to initiate life on reaching a suitable environment."
Wickmarasinge and Hoyle theorized that panspermia not only explained the origin of life, but that, from time to time, new organisms arrived from space and these new organisms integrated into existing species, the new DNA providing the instructions for new forms of life, i.e dinosaurs and mammals. New DNA sequencing of large stretches of DNA and entire genomes have falsified the theory.
So even as late as 1982 there was a competitor for common ancestry.
