Charles Darwin: Ihmisen alkuperä

Charles Darwin Descent of Man
kuva wikimedia

Charles Darwin (1809-1882) oli luonnollisesti kiinnostunut ihmisen kehityksestä.

(Voiko tuon latteammin asian sanoa?)

Vuonna 1859 hän julkaisi mullistavan teoksensa Origins of the Species. 12 vuotta myöhemmin hän julkaisi ihmisen kehitystä koskevan teoksen nimellä The Descent of Man, and Selection in Relation to Sex (1871).

Tästä ihmiskunnan kannalta niin tärkeästä teoksesta on wikipediassa muutamia varsin arvokkaita havaintoja, joiden suomentaminen on vaikeaa. Uskallan taas olettaa, että aika moni, joka vaivautuu lukemaan blogia, joka on otsikoitu Homo erectus taitaa myös Darwinin äidinkieltä.

1. Erityinen luomus vai yhteistä elämän historiaa?

 "Charles Darwin's Origin of Species had been met with a firestorm of controversy in reaction to Darwin's theory, largely because it clearly implied that human beings were evolved from animals, contradicting the biblical story in the Book of Genesis."

2. Miksi nainen on kaunis ja mies komea?

It is often erroneously assumed that the book was controversial because it was the first to outline the idea of human evolution and common descent. Coming out so late into that particular debate, while it was clearly Darwin's intent to weigh in on this question, his goal was to approach it through a specific theoretical lens (sexual selection), which other commentators at the period had not discussed, and consider the evolution of morality and religion. 

The theory of sexual selection was also needed to counter the argument that beauty with no obvious utility, such as exotic birds' plumage, proved divine design, which had been put strongly by the Duke of Argyll in his book The Reign of Law (1868).

3. Viisas ihminen, tyhmä apina?

The major sticking point for many in the question of human evolution was whether human mental faculties could have possibly been evolved. The gap between humans and even the smartest ape seemed too large, even for those who were sympathetic to Darwin's basic theory.Alfred Russel Wallace, the "co-discoverer" of evolution by natural selection, believed that the human mind was too complex to have evolved gradually, and began over time to subscribe to a theory of evolution that took more from Spiritualism than it did the natural world. 

Darwin was deeply distressed by Wallace's change of heart, and much of the Descent of Man is in response to opinions put forth by Wallace. Darwin focuses less on the question of whether humans evolved than he does on showing that each of the human faculties considered to be so far beyond those of animals—such as moral reasoning, sympathy for others, beauty, and music—can be seen in kind (if not degree) in other animal species (usually apes and dogs).

4. Mieheksi ja naiseksi = seksi

More difficult for Darwin were highly evolved and complicated features that conveyed apparently no adaptive advantage to the organism. Writing to colleague Asa Gray in 1860, Darwin commented that he remembered well a "time when the thought of the eye made me cold all over, but I have got over this stage of the complaint, & now small trifling particulars of structure often make me very uncomfortable. The sight of a feather in a peacock's tail, whenever I gaze at it, makes me sick!"

Why should a bird like the peacock develop such an elaborate tail, which seemed at best to be a hindrance in its "struggle for existence"? 

To answer the question, Darwin had introduced in the Origin the theory of sexual selection, which outlined how different characteristics could be selected for if they conveyed a reproductive advantage to the individual. 

In this theory, male animals in particular showed heritable features acquired by sexual selection, such as "weapons" with which to fight over females with other males, or beautiful plumage with which to woo the female animals. Much of Descent is devoted to providing evidence for sexual selection in nature, which he also ties in to the development of aesthetic instincts in human beings, as well as the differences in coloration between the human races.

Lainaukset ovat Darwinin kirjaa kuvaavasta tasokkaasta wikipedian artikkelista 

Siellä on aiheesta paljon muutakin, ja suosittelen sen lukemista kokonaan.

Darwinin kirja ihmisestä taitaa olla melko lailla avain ymmärtääksemme oman aikamme ihmisen käsitystä itsestään ja maailmasta. Jumalastakin.

P.S.
Huomaatko muuten, miten jännittävästi Charles Darwinin keskeinen lähestymistapa ihmisen kehitykseen viittaa luomiskertomukseen - mieheksi ja naiseksi!

Samalla tavoin Darwinin pääteos, Lajien synty, viittaa luomiskertomuksessa jatkuvasti toistuvaan ilmaisuun leminehu, lajiensa mukaan.