Changing Lifeforms

Popular culture has a tendency to not be scientific or at least NOT to look at the natural world in a methodical way. Pop culture takes the Theory of Evolution as that all presently existing life is the result of a progressively upward change from lesser form to higher form, that Survival of the Fittest means today’s lifeforms are both higher and more fit than predecessors and continue to naturally become better adapted because they currently exist so must be more fit than earlier models.

ADAPTATIONS RATHER THAN ORIGINS
A little understanding of current evolutionary theories: Charles Darwin’s theory does not primarily address the origins of life but rather the changes that happen in lifeforms over time. He was most interested in the adaptations of lifeforms to the environments in which they lived which made them more survivable in that setting, more likely to multiple and continue in that adaptation. But, he did not presume that all adaptations were “better” and realized that some adaptations made for a stability which wasn’t adaptable to further environmental changes and even those which could result in a lifeform becoming extent because it couldn’t adapt. He also recognized that adaptations could be rapid – even in a single lifespan as forms changed with changing surroundings. He also did not propose that evolution was a steady progress across time but acknowledged that different levels of life and different branches of a species could and would develop at different rates.

Proponents of the Theory of Evolution have redefined “theory” in a way that does address their divergence from the Scientific Method of Hypothesis, Theory, Experiment, Observe, Analyze and Quantify by treating Theory as the explanation of phenomena as accepted by the larger scientific community as supported by multiple lines of evidence. In part, this is necessary because the scope of time relative to the period of consideration is vastly shorter. Evolution seeks to relate to 4.5 billion years of Earth existence while the length of the studies is less than 200 years. Darwin (1809-1882) began his education apprenticing to his doctor father and then went on to University studying medicine before gravitating toward natural history. It was his journey from England to the west coast of South America on the HMS Beagle beginning late in 1831 as a naturalist that exposed him to a vast selection of lifefoms as the voyage lasted almost 5 years and circumnavigated the world. With the vast exposure of the journey, he began his inquiry into the meaning of all he had observed and began to compose his observations into a theory of natural selection beginning with an essay on observations in barnacles (1846) which was published scientifically in 1854. Then in 1856 he began writing public papers on Natural Selection in species and expanded its scope to include applications to humans, published late in 1859.

While Darwin made extensive observations and theorized on natural selection, it was Gregor Mendel (1822-1884) who is considered to be the father of genetics and established the basic understanding of heredity and hybridization. This provided more than hypothesis to genetics and explained how many “random” mutations occurred. Mendel’s main work was published in 1866 and was developed more on experimentation than Darwin’s observations. Mendel was focused on the means by which changes typically took place genetically and proposed the scientific link to change within species.

Moving into the Twentieth Century with modern technologies available in science, re-evaluations of evolution added alternate means of mutation both micro and macro in results. Genetic diversity within species could be categorized at a cellular level and then in mid-century, at the molecular level. Evolution expanded from biological to social to even the idea of evolutionary computation and artificial intelligence. It also brought the possibility and then the actualization of gene splicing and CRISPR. CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats) is the science of a genome-editing technique using a specific DNA fragment to “alter” or edit genes within a living organism. [compiler: grossly over-simplified definition]

To overview the complexity of popularly-perceived evolution, we present a few suspected milestones:¹

1. Great Oxidation Event – 2.4-2.06 billion years ago, mass extinction of all but a few of the existing lifeforms when Earth experienced rise in concentration of free oxygen causing oxidation of minerals and lifeforms that were not adaptable to these higher concentrations because they were dependent upon higher nitrogen and carbon dioxide levels. Oxygen is theorized to have been 0.001% of contemporary levels before the GOE but rose to levels toxic to earlier obligate anaerobic² lifeforms dependent upon the more inert gases. This also paralleled the early plate tectonic subductions which changed Earth’s surface topography.
2. End Ordovician – 440 million years ago with 86% of existing species going extinction
3. Late Devonian – 375 million years ago with 75% of existing species going extinction
4. End Permian “The Great Dying” – 251 million years ago with 96% extinction
5. End Triassic – 200 million years ago with 80% extinction
6. End Cretaceous – 66 million years ago with 76% extinction including plesiosaurs, pterosaurs and non-avian dinosaurs

Contemporary estimates are that 99.9% of all species have gone extinct. In estimated numbers, over 5 billion species have gone extinct while there are estimated to be 8.7 million species existing at this point in time. Species included are “prokaryotes” which are bacterium and archaea and the more obvious “eukaryotes” which are plants, animals, fungi and protists.³

The causes of the last five mass extinctions are presented in a 2022 proposal by Hannah Ritchie:⁴

- End Ordovician as intense glacial and interglacial periods, tectonic uplifts and changes in climate and ocean chemistry
- Late Devonian as rapid growth and diversification of land plants generated rapid, severe global cooling
- End Permian as intense volcanic activity in Siberia causes global warming. Elevated CO2 and H2S gases cause ocean acidification, acid rain and other changes in life zones
- End Triassic as underwater volcanic activity in Central Atlantic Magmatic zone causes global warming and ocean chemistry composition changes
- End Cretaceous as asteroid impact in Yucatan (Mexico) brings global cataclysm and rapid cooling. May have been preceded by other volcanic and tectonic activities

Records held by the IUCN (International Union for Conservation of Nature), indicate that since 1500, 881 animal species have gone extinct. Some scientists suspect that an additional 592 species are also extinct in that period but have not been verified as such.⁵ The quoted article follows the contemporary view that “never have so many species gone extinct in so short a time” but this may exceed the science as at least some of the mass extinctions were cataclysmic and rapid. Global Winter was rapid onset as we have seen from the article on Climate Change. The IUCN statistics assess an extinction rate of 5% of known species (not just animal cited above) but extrapolate that not all species are identified so it follows that the actual number of extinctions could be significantly higher. In a 2022 study published in the journal Biological Review,

…it was suggested that as many as 150,000 to 260,000 known species could have perished since 1500 if we had known them.⁶

Not all peer review was convinced of the science of the mathematics and generalizations across species and all terms being equal to the period proposed in the study yet these numbers were enthusiastically embraced by media as supportive of the dire risk of this being another era of mass extinction.

Social media rather than science has posted that “humans have driven 381,150 animal species to extinction” but there are no published scientific studies arriving at this conclusion.

Getting back to Evolution, not all species adapt or mutate. Not all species who do adapt survive. At any time, survival of the “fittest” may not continue as has been seen in the mass extinctions. There are several reasons that a species may cease to exist:

1. A species may mutate into a ‘daughter’ species while the parent species ceases to exist. Pseudo-extinction.
2. A species may disappear from observation for a time either by dormancy or by limiting observability to where observations are not available.
3. Genetic pollution with a degree of diversity in that species genes that renders it unsustainable.
4. Environmental degradation where the environment changes and becomes non-supportive of the species. Climate change
5. Competition with other species for food or as food or inability to overcome disease results in the loss of sustainable population. Predatory
6. Loss of symbiotic relationship with food source or another species to which this species depended for support in adaptation.

In the late 1700s, Charles Darwin’s grandfather Erasmus Darwin proposal that transmutation of species was enhanced by the published work of Lamarck in 1809 hypothesizing spontaneous generation had produced forms of life that progressively developed greater complexity and emphasized ‘greater’ and ‘better’ with little possibility of extinction. Charles did not concur even though he did espouse natural selection and survival of the fittest because his observations indicated that species do go extinct.

LUCA – Last Universal Common Ancestor
LUCA (last universal common ancestor) was so designated in the 1990s for the single ancestor of all lifeforms. While Lucy⁸ was named in 1974 as ancestor of all hominin species (pre-human), LUCA is contemporarily proposed as the ancestor – albeit single cell – of all life whether unicellular or multicellular, plant, animal, bacteria or archaea. This LUCA designator filled a need in the Theory for a commonality; Darwin’s 1859 included the need, “Therefore I should infer from analogy that probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed.”⁷ While LUCA provides a source, it is no more supported by fact as to origin than any other means and was challenged for a couple decades before a “test” was published by Theobald which dealt with the common descent of all existing Earth organisms and called it UCA (universal common ancestor) which satisfied a greater sense of science but then an earlier, non-cellular ancestor, FUCA (first UCA) was proposed which gave more flexibility to the theory as FUCA was entitled to have multiple lines of descendants, not limited to vertical but also horizontal in the tree. This endeavors to give place to viruses which don’t fit quite as well into the branching out from LUCA.

A brief word about Devolution:

Devolution is the theory that lifeforms go from a more complex level to a less complex level, that in natural selection, species revert to earlier, more primitive forms over time. Evolution makes no judgment on “progress” as to whether it is “better” or “higher” but rather about what is now is more survivable than what is no more. The science of purposeful, increasing complexity is a derivation of Darwin’s grandfather and Lamarck’s belief that became orthogenesis – progressive, progress, better – that evolution contained by nature the linear direction toward higher forms without possibility of failure to survive and thrive. ‘Ortho’ meaning straight plus ‘genesis’ origin sees life forms as having a self perfecting mechanism that guides the organism in a directed manner only in the better sustainability. In evolutionary biology, this is still argued but comes into conflict with itself. This is ‘better’ applied in Physics, Chemisty, Mysticism, Physiology and other sciences that are directed by the constraints of form and formula with mindful intervention.

FOOTNOTES:
Compiler’s Note: the use of “lifeform” rather than “life-form” is non-traditional but more accurately indicates organic life as a distinct unit.

¹ this list of milestones of life are outtakes from the Wikipedia Timeline of the Evolutionary History of Life referenced in resources following.
² Obligate anaerobes are lifeforms, microorganisms, which cannot survive ‘normal’ atmospheric O₂ levels. Anaerobic indicates without oxygen. Typical of fermentation or anaerobic respiration.
³ “procaryote” are unicellular microorganisms lacking specific nucleus or distinct organs
“eukaryote” are multicellular organisms with distinct nucleus and organs
⁴ Hannah Ritchie (2022) – “There have been five mass extinctions in Earth’s history” Published online at OurWorldinData.org. Retrieved from: https://ourworldindata.org/mass-extinctions
⁵ https://www.reuters.com/lifestyle/science/extinction-crisis-puts-1-million-species-brink-2022-12-23/
⁶ https://www.livescience.com/animals/how-many-animal-species-have-humans-driven-to-extinction
⁷ Darwin, Charles (1859). The Origin of Species by Means of Natural Selection. Published by John Murray Publishing House, pp. 484, 490
⁸ LUCY was compiled from several hundred bone fragments excavated from a gully with no duplication indicating they were all from a single individual. Approximately 40% complete. Using argon-argon technology for dating the site under the specimen, in 1990 Lucy was dated circa 3.22 to 3.18 million years ago.

For further resources related to this article:

Changing Lifeforms

Links to Articles on Science

THEORY vs. REALITY

CHANGING CLIMATES

CHANGING LIFEFORMS