Monday, December 30, 2013

Evolution Before Darwin
[+ Some History and Information]

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EVOLUTION BEFORE DARWIN [+]

Firstly, we must answer the obvious questions and provide some examples and evidence for evolution before moving on to the primary topic of this post (or, evolution before Darwin -- click on any of the images below to enlarge them if necessary):

“What is Evolution?”

Evolution is the process of change in gene frequency, which may result in new species from pre-existing species (see: http://en.wikipedia.org/wiki/Evolution).

“What provides the driving force for evolution?”


Evolution is driven by gene mutations that cause variations among members of a species (ex: some people are resistant to HIV infection because they have a defective CCR5 receptor; http://en.wikipedia.org/wiki/CCR5).

“What evidence is there for evolution?”

*Evolutionary “proof” and some theories:

Unlike with bacteria, which we can track the evolution of (Click Here), it is slightly more difficult to track human evolution (but evidence is out there). We don't have precise or comprehensive enough records to see how our species has evolved, specifically, or with absolute accuracy, over the many years. It is much a problem in the same way that people don't notice themselves growing. We can only know about evolution in the human species by comparing humans from a very large, and long, sample size.

One can, nonetheless, see it, in particular, in our vestigial organs and more.

Some current mutations (often beneficial): hypermobility, chimerism, atavism, pigments, mosaicism, intersexuality, supernumerary, tetrachromacy, polyploidism, digestions, acclimation and acclimatization, shapes and sizes, races, speech and song (FOXP2), et cetera.

*See:
http://en.wikipedia.org/wiki/Hypermobility_(joints)
http://en.wikipedia.org/wiki/Chimera_(genetics)
http://en.wikipedia.org/wiki/Atavism
http://en.wikipedia.org/wiki/Human_skin_color
http://en.wikipedia.org/wiki/Mosaic_(genetics)
http://en.wikipedia.org/wiki/Intersex
http://en.wikipedia.org/wiki/Pseudohermaphroditism
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1206491/pdf/ge13941649.pdf
http://en.wikipedia.org/wiki/Supernumerary_body_part
http://onlinelibrary.wiley.com/doi/10.1046/j.1420-9101.1993.6030417.x/pdf
http://en.wikipedia.org/wiki/Supernumerary_chromosome
http://en.wikipedia.org/wiki/Tetrachromacy
http://en.wikipedia.org/wiki/Polyploid
http://www.nature.com/scitable/topicpage/polyploidy-1552814
http://en.wikipedia.org/wiki/Digestion
http://en.wikipedia.org/wiki/Acclimatization
http://biomed.brown.edu/Courses/BIO48/30.S&S.HTML
http://www.naturalhistorymag.com/picks-from-the-past/12479/size-and-shape
http://en.wikipedia.org/wiki/Race_(human_classification)
http://ncse.com/evolution/science/evolution-origin-races
http://en.wikipedia.org/wiki/Origin_of_language
http://en.wikipedia.org/wiki/Origin_of_speech
http://www2.lawrence.edu/fast/KOOPMAJO/antiquity.html
http://www.economist.com/node/12795510
http://www.npr.org/templates/story/story.php?storyId=129155123
http://en.wikipedia.org/wiki/FOXP2

*Also see:
http://www.npr.org/templates/story/story.php?storyId=5230538
http://www.nature.com/scitable/topicpage/atavism-embryology-development-and-evolution-843

Speciation, generation, and greater, which are what many people think of when they think of "evolution," however, do not take tens of thousands of years (see: Click HereClick Here). A few animals and plants take several years, and the newest are a few decades to a century old (consider: http://www.bbc.co.uk/nature/20425468). Cladogenesis takes at least a land/mating barrier which disperses a deme into ring species that are unable to interbreed at the ends (consider: http://en.wikipedia.org/wiki/Cladogenesis).

(We'll get back to some of the above later.)

*Some related ideas - Toba catastrophe theory (http://en.wikipedia.org/wiki/Toba_catastrophe_theory):

Further than that are extinction level events which kill off nearly every member of a species so that alleles are taken out of the equilibrium (when survivors must inbreed and amplify their mutations). The last time that this occurred with humans was around 70,000 years ago following the Toba supereruption, when there were only about 10,000 Homines sapientes remaining. Their diaspora brought about all races:

http://en.wikipedia.org/wiki/Human_mitochondrial_DNA_haplogroup
http://en.wikipedia.org/wiki/Human_Y-chromosome_DNA_haplogroup

Our final partial ancestors and cousins, who shared the most DNA with us, were groups such as the Neanderthals, Heidelbergers and Denisovans (see: Click Here; Click Here; Click Here). But, they were the wrong sizes and shapes; the Neanderthal skull was too large, and childbirth, too painful. None of them could master consonants and ranged weapons as the sapientes could. They were, it is believed, wiped out by glaciers and our encroachment.

*Some of our best evidence - the fossil record:

Trilobites (http://en.wikipedia.org/wiki/Trilobite) lived on Earth from 540 million years ago to up until 245 million years ago. // ("Trilobites (/ˈtraɪlɵbaɪt/, /ˈtrɪlɵbaɪt/; meaning 'three lobes') are a well-known fossil group of extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest known groups of arthropods..." // "The study of these fossils has facilitated important contributions to biostratigraphy, paleontology, evolutionary biology and plate tectonics."):


Likewise, we have fossils of dinosaurs with wings, and can, from the information and evidence that we've compiled, track the evolution of the wing and the path to birds (Sinosauropteryx; Velociraptor; Unenlagia; Caudipteryx; Protarchaeopteryx; Archaeopteryx; Eoalulavis; Corvus):


We also have fossils of horses with toes, and from this, we can observe the transformation of the horses’ foot structure over time (Hyracotherium; Mesohippus; Merychippus; Pliohippus; Equus):


And, we have fossils of whales with legs (ex: Ambulocetus, a 45-million-year-old whale; http://en.wikipedia.org/wiki/Ambulocetus). The many transitional forms chronologically (general understanding): Mesonychids; Pakicetus; Ambulocetus; Dalanisters; Rodhocetus; Takracetus; Gaviocetus; Dorudon; Basilosaurus; Mysticetes; Odontocetes -- this gradual transformation, or evolution, takes place over a period of tens of millions of years:


Even modernly, the inside of a whale’s flipper contains a hand, complete with fingers and a wrist, and while fish swim by moving their tails from side-to-side, whales swim by moving their tails up-and-down.
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In essence, the fossil record allows us to catalog the transitional forms of creatures that have lived/do live on the planet Earth (forms such as the Archaeopteryx, which is the link between dinosaurs and birds; http://en.wikipedia.org/wiki/Archaeopteryx):


There are a myriad of other examples that could be presented in addition to the ones that I've presented above, such as the lobe-finned lungfish (see: http://en.wikipedia.org/wiki/Sarcopterygii; they are the ancestors of amphibians):


“What is homology? // What are homologous structures?”

“In the context of biology, homology is the existence of shared ancestry between a pair of structures, or genes, in different species. A common example of homologous structures in evolutionary biology are the wings of bats and the arms of primates. Evolutionary theory explains the existence of homologous structures adapted to different purposes as the result of descent with modification from a common ancestor.” (see: http://en.wikipedia.org/wiki/Homology_(biology))

(*The above image is a depiction of some homologous structures.)

Essentially, homology tells us that A) the genes that encode things like the forelimbs in the diagram above are very similar, and B) that these organisms share a common ancestor that had forelimbs with the same parts.

“What are vestigial structures?”

Vestigial structures are, basically, body parts that seem to have no use in some species when similar structures are quite useful in related species (see: http://en.wikipedia.org/wiki/Vestigiality).

*Ex: In 1919, a Humpback whale was found with hind legs (see: Click Here; this one has a rather ridiculously lengthy hyperlink, so I shortened it for aesthetic purposes).

“What vestigial structures do humans have?”

(*The above image is of the Vitruvian Man by Leonardo da Vinci.)

*See: http://en.wikipedia.org/wiki/Human_vestigiality

As a specific example, some humans are born with visible tails, which are vestigial:


Normally, by the end of the second month of gestation (see: http://en.wikipedia.org/wiki/Gestation), the tail disappears (virtually all human embryos have tails while in the womb, which are typically absorbed by the growing body as the embryo develops into a fetus; http://en.wikipedia.org/wiki/Tail). However, once in a great while, a baby is born with the tail still visible.

“What is Natural Selection?”

“Natural selection is the gradual process by which biological traits become either more or less common in a population as a function of the effect of inherited traits on the differential reproductive success of organisms interacting with their environment. It is a key mechanism of evolution. The term "natural selection" was popularized by Charles Darwin who intended it to be compared with artificial selection, which is now called selective breeding.” (see: http://en.wikipedia.org/wiki/Natural_selection)

Now, while Charles Darwin wasn't the first to propose and/or to consider the idea of evolution by natural selection (I will discuss this more later), he was the one who popularized it, primarily with his book “On the Origin of Species” (see: http://en.wikipedia.org/wiki/On_the_Origin_of_Species). Essentially, Darwin raised the idea of natural selection from a hypothesis to a verifiable theory.

*Natural Selection is a multi-phase process:
1) Overproduction: Many organisms are produced.
2) Variation: Some organisms have different genetic traits than others.
3) Competition: Organisms struggle for resources and mates.
4) Survival of the Fittest: The organisms with the traits better suited for the environment subsist while others die off (become extinct).
5) Reproduction of the Fittest: The surviving organisms reproduce giving their offspring better traits to survive.
6) Speciation: Selective mating, resulting in reduced gene flow (subgroup divergence resulting in different species).

Natural Selection acts on individuals; species change and adapt (primarily based on the circumstances and difficulties presented by/within their environment).
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Supplementary Information:

*Many creatures living on this planet have similar embryos:
(*The above image is of the embryos of various species; click to enlarge.)

(*The above image is of 570-million-year-old microscopic fossil embryos, discovered in 1998.)

Likewise, there are biochemical similarities between species (DNA similarities; protein similarity: the same 20 amino acids are found in all species’ proteins):


And, there is a universal genetic code (see: http://www.bioinformatics.nl/webportal/background/geneticcodeinfo.html):


“It (The Universal Genetic Code) is known as "universal", because it is used by all known organisms as a code for DNA, mRNA, and tRNA. The universality of the genetic code is used in animals (including humans), plants, fungi, archaea, bacteria, and viruses. However, all rules have their exceptions, and such is the case with the Genetic Code; small variations in the code exist in mitochondria and certain microbes. Nonetheless, it should be emphasised that these variances represent only a small fraction of known cases, and that the Genetic Code applies quite broadly, certainly to all known nuclear genes.”
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Now that all of that is out of the way, we can move on to the primary topic of this post (evolution before Darwin -- which is briefer than all of the above):

*Evolution by Natural Selection before Darwin:

Pythagoras, Greek philosopher, lived from 582 to 497 BC (see: http://en.wikipedia.org/wiki/Pythagoras).


*He said: “Nature preserves the fit and discards the unfit.”

+William Wells, James Prichard, William Lawrence (1813): All advanced the theory of natural selection in published essays or books (see: http://en.wikipedia.org/wiki/William_Charles_Wells; http://en.wikipedia.org/wiki/James_Cowles_Prichard; http://en.wikipedia.org/wiki/William_Lawrence_(biologist)).

*Note: Lawrence’s book “Lectures on Physiology, Zoology, and the Natural History of Man” was published in 9 editions by 1848.

*Evolution before (Charles) Darwin:

Erasmus Darwin, Grandfather of Charles Darwin, English physician, lived from December 12, 1731 to April 18, 1802 (see: http://en.wikipedia.org/wiki/Erasmus_Darwin):


“…Organic life beneath the shoreless waves
Was born and nurs’d in ocean’s pearly caves;
First forms minute, unseen by spheric glass,
Move on the mud, or pierce the watery mass;
These, as successive generations bloom,
New powers acquire and larger limbs assume;
Whence countless groups of vegetation spring,
And breathing realms of fin and feet and wing…”
(The Temple of Nature, Canto I, 1803; http://www.rc.umd.edu/editions/darwin_temple)
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Of course, Charles Darwin is likely the most historically well-known and recognized figure in relation to Natural Selection and Evolution in general, but he was not the first to propose/consider such ideas; he was merely the first to truly popularize them.

This is not to discredit him in any way, but it is interesting to read about others who contributed to the concept(s) that he popularized prior to his primary body-of-work and research (and, this sort of thing is among the topics that I enjoy researching and learning about the most).

(*The above image is of Charlie D. looking dapper.)

(*The above image is of D. Charlie's book on how to properly cultivate fruit trees.)

*See: http://en.wikipedia.org/wiki/Charles_Darwin, lived from February 12, 1809 to April 19, 1882; http://en.wikipedia.org/wiki/On_the_Origin_of_Species, first published on November 24, 1859.
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Hopefully, this post was as instructive and interesting for my viewers to read as it was enjoyable for me to assemble. My next post will likely be regarding genetics, and I hope that everyone will enjoy that piece as well.

Thank you all for reading.

Sincerely,
Femitheist Divine

P.S. I did this post in roughly around two hours, so I left out some of the information that I gathered; I may create a new post with it or add it to this post at another time.

Relevant References in Order (Last Accessed on December 30, 2013):
http://en.wikipedia.org/wiki/Evolution
http://en.wikipedia.org/wiki/CCR5
http://blogs.discovermagazine.com/notrocketscience/2011/11/13/scientists-track-the-evolution-of-an-epidemic-to-show-how-bacteria-adapt/
http://en.wikipedia.org/wiki/Hypermobility_(joints)
http://en.wikipedia.org/wiki/Chimera_(genetics)
http://en.wikipedia.org/wiki/Atavism
http://en.wikipedia.org/wiki/Human_skin_color
http://en.wikipedia.org/wiki/Mosaic_(genetics)
http://en.wikipedia.org/wiki/Intersex
http://en.wikipedia.org/wiki/Pseudohermaphroditism
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1206491/pdf/ge13941649.pdf
http://en.wikipedia.org/wiki/Supernumerary_body_part
http://onlinelibrary.wiley.com/doi/10.1046/j.1420-9101.1993.6030417.x/pdf
http://en.wikipedia.org/wiki/Supernumerary_chromosome
http://en.wikipedia.org/wiki/Tetrachromacy
http://en.wikipedia.org/wiki/Polyploid
http://www.nature.com/scitable/topicpage/polyploidy-1552814
http://en.wikipedia.org/wiki/Digestion
http://en.wikipedia.org/wiki/Acclimatization
http://biomed.brown.edu/Courses/BIO48/30.S&S.HTML
http://www.naturalhistorymag.com/picks-from-the-past/12479/size-and-shape
http://en.wikipedia.org/wiki/Race_(human_classification)
http://ncse.com/evolution/science/evolution-origin-races
http://en.wikipedia.org/wiki/Origin_of_language
http://en.wikipedia.org/wiki/Origin_of_speech
http://www2.lawrence.edu/fast/KOOPMAJO/antiquity.html
http://www.economist.com/node/12795510
http://www.npr.org/templates/story/story.php?storyId=129155123
http://en.wikipedia.org/wiki/FOXP2
http://www.npr.org/templates/story/story.php?storyId=5230538
http://www.nature.com/scitable/topicpage/atavism-embryology-development-and-evolution-843
http://en.wikipedia.org/wiki/Speciation
http://en.wikipedia.org/wiki/Generation
http://www.bbc.co.uk/nature/20425468
http://en.wikipedia.org/wiki/Cladogenesis
http://en.wikipedia.org/wiki/Human_mitochondrial_DNA_haplogroup
http://en.wikipedia.org/wiki/Human_Y-chromosome_DNA_haplogroup
http://en.wikipedia.org/wiki/Neanderthal
http://en.wikipedia.org/wiki/Homo_heidelbergensis
http://en.wikipedia.org/wiki/Denisovan
http://en.wikipedia.org/wiki/Trilobite
http://en.wikipedia.org/wiki/Ambulocetus
http://en.wikipedia.org/wiki/Archaeopteryx
http://en.wikipedia.org/wiki/Sarcopterygii
http://en.wikipedia.org/wiki/Homology_(biology)
http://en.wikipedia.org/wiki/Vestigiality
http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/4849/N0009.pdf;jsessionid=A58363B5A175FAFBBF1661509AC13178?sequence=1
http://en.wikipedia.org/wiki/Human_vestigiality
http://en.wikipedia.org/wiki/Gestation
http://en.wikipedia.org/wiki/Tail
http://en.wikipedia.org/wiki/Natural_selection
http://en.wikipedia.org/wiki/On_the_Origin_of_Species
http://www.bioinformatics.nl/webportal/background/geneticcodeinfo.html
http://en.wikipedia.org/wiki/Pythagoras
http://en.wikipedia.org/wiki/William_Charles_Wells
http://en.wikipedia.org/wiki/James_Cowles_Prichard
http://en.wikipedia.org/wiki/William_Lawrence_(biologist)
http://en.wikipedia.org/wiki/Erasmus_Darwin
http://www.rc.umd.edu/editions/darwin_temple
http://en.wikipedia.org/wiki/Charles_Darwin