Myths and misconceptions about evolution - Alex Gendler

Mitovi i zablude o evoluciji - Aleks Gendler (Alex Gendler)

Prevodilac: Jelena Jaranović Lektor: Tatjana Jevdjic

Myths and misconceptions about evolution.

Mitovi i zablude o evoluciji.

Let's talk about evolution.

Hajde da pričamo o evoluciji.

You've probably heard

Verovatno ste čuli

that some people consider it controversial,

da neki ljudi misle da je ideja sporna

even though most scientists don't.

iako se mnogi naučnici sa tim ne slažu.

But even if you aren't one of those people

Čak i ako ne pripadate tim ljudima

and you think you have a pretty good understanding of evolution,

i mislite da prilično dobro razumete evoluciju

chances are you still believe some things about it

verovatno i dalje verujete u neke stvari

that aren't entirely right,

koje nisu sasvim tačne,

things like,

poput:

"Evolution is organisms adapting to their environment."

"Evolucija predstavlja prilagođavanje organizma okruženju."

This was an earlier,

Ovo je jedna zastarela,

now discredited,

sada odbačena,

theory of evolution.

teorija evolucije.

Almost 60 years before Darwin published his book,

Gotovo 60 godina pre nego što je Darvin objavio svoju knjigu,

Jean-Baptiste Lamarck proposed

Žan Baptist Lamark je rekao

that creatures evolve by developing

da bića evoluiraju tako što razvijaju

certain traits over their lifetimes

određene karakteristike tokom života

and then passing those on to their offspring.

i onda ih prenose na potomstvo.

For example, he thought

On je mislio, na primer,

that because giraffes spent their lives

da zato što žirafe provode život

stretching to reach leaves on higher branches,

istežući se da dohvate lišće na visokim granama,

their children would be born with longer necks.

njihovi mladunci će se roditi sa dužim vratovima.

But we know now that's not how genetic inheritance works.

Ali danas znamo da genetika ne funkcioniše tako.

In fact, individual organisms don't evolve at all.

U stvari, jedinka ne evoluira uopšte.

Instead, random genetic mutations cause

Zapravo, slučajne genetske mutacije dovode to toga

some giraffes to be born with longer necks,

da se neke žirafe rađaju sa dužim vratovima

and that gives them a better chance to survive

i to im daje bolje šanse da prežive

than the ones who weren't so lucky,

nego one koje nisu imale toliko sreće,

which brings us to

što nas dovodi do

"survival of the fittest".

"preživljavanje najsposobnijih".

This makes it sound like evolution always favors

Ovo zvuči kao da evolucija uvek bira

the biggest,

najveće,

strongest,

najjače

or fastest creatures,

ili najbrže jedinke,

which is not really the case.

što u stvari nije slučaj.

For one thing, evolutionary fitness is just a matter

Prvo, evoluciona spremnost se odnosi na to

of how well-suited they are to their current environment.

koliko je jedinka prilagođena trenutnom okruženju.

If all the tall trees suddenly died out

Ako bi svo visoko drveće iznenada nestalo

and only short grass was left,

i ostala samo trava

all those long-necked giraffes

sve one dugovrate žirafe

would be at a disadvantage.

ne bi više bile u prednosti.

Secondly, survival is not how evolution occurs,

Drugo, evolucija se ne ostvaruje kroz preživljavanje

reproduction is.

već kroz razmnožavanje.

And the world if full of creatures

I svet je pun stvorenja

like the male anglerfish,

poput mužjaka morskog đavola,

which is so small and ill-suited for survival at birth

koji je toliko mali i nespreman da preživi na rođenju

that it has to quickly find a mate before it dies.

da mora brzo da nađe partnera pre nego što umre.

But at least we can say

Ali barem možemo reći

that if an organism dies without reproducing,

da ako organizam umre, a nije se razmnožio pre toga

it's evolutionarily useless, right?

on je evolutivno beskoristan, zar ne?

Wrong!

Pogrešno!

Remember, natural selection happens

Zapamtite, prirodna selekcija se ne događa

not at the organism level,

na nivou organizma

but at the genetic level,

već na genetskom nivou,

and the same gene that exists in one organism

a gen koji postoji u jednom organizmu

will also exist in its relatives.

postoji i kod njegovih rođaka.

So, a gene that makes an animal altruistically sacrifice itself

Dakle, gen koji podstiče neku životinju da se žrtvuje

to help the survival and future reproduction

kako bi pomogla preživljavanje i buduće razmnožavanje

of its siblings or cousins,

svoje braće, sestara ili rođaka,

can become more widespread

može postati rasprostranjenija

than one that is solely concerned with self-preservation.

nego životinje koje su usmerene na samo-preživljavanje.

Anything that lets more copies of the gene

Sve što obezbeđuje da se što više kopija gena

pass on to the next generation

prenese na sledeću generaciju

will serve its purpose,

će poslužiti svrsi,

except

izuzev

evolutionary purpose.

evolucionoj svrsi.

One of the most difficult things to keep in mind about evolution

Treba imati na umu

is that when we say things like,

da kada kažemo stvari poput:

"Genes want to make more copies of themselves,"

"Geni žele da naprave što više svojih kopija"

or even,

ili

"natural selection,"

"prirodna selekcija",

we're actually using metaphors.

mi, u stvari, koristimo metafore.

A gene doesn't want anything,

Geni ne žele ništa

and there's no outside mechanism

i ne postoji spoljni mehanizam

that selects which genes are best to preserve.

koji određuje koji geni su najbolji i treba ih sačuvati.

All that happens is that random genetic mutations

Sve što se događa je da nasumične genetske mutacije

cause the organisms carrying them

utiču na organizam koji ih poseduje

to behave or develop in different ways.

da se ponaša ili razvija na drugačiji način.

Some of those ways result in more copies

Neke od posledica su da se više kopija

of the mutated gene being passed on,

mutiranih gena prenosi na sledeću generaciju

and so forth.

i tako dalje.

Nor is there any predetermined plan

Niti postoji neki predodređeni plan

progressing towards an ideal form.

po kome se ide ka savršenoj formi.

It's not ideal for the human eye to have a blind spot

Za ljudsko oko nije savršeno da ima slepu mrlju

where the optic nerve exits the retina,

gde optički nerv izlazi iz mrežnjače,

but that's how it developed,

ali oko se tako razvilo

starting from a simple photoreceptor cell.

od jednostavne fotoreceptorske ćelije.

In retrospect, it would have been

Opšte uzev, možda bi za ljude bilo

much more advantageous for humans to crave

mnogo bolje da su razvili potrebu

nutrients and vitamins

za hranljivim materijama i vitaminima

rather than just calories.

nego samo za kalorijama.

But over the millenia,

Ali tokom vekova,

during which our ancestors evolved,

tokom kojih su naši preci evoluirali,

kalorija nije bilo dovoljno

calories were scarce,

and there was nothing to anticipate

i ništa nije moglo nagovestiti

da će se ovo kasnije tako brzo promeniti.

that this would later change so quickly.

So, evolution proceeds blindly,

Dakle, evolucija nastupa slepo,

step

korak

by step

po korak,

by step,

po korak,

creating all of the diversity we see in the natural world.

stvarajući svu raznovrsnost koju vidimo oko nas.