Evolution and adding genes?

Question

So, I got one of these forwards about how simple lifeforms have less genes than us and that apparently they don't believe genes can be added.

Here's an excerpt:

"There is No Genetic Mechanism for Darwinian Evolution Darwinists claim we evolved from the simplest form of bacterial life to ever more complex forms of life. The most basic bacteria had less than 500 genes; man has over 22 thousand. In order for bacteria to evolve into man, organisms would have to be able to add genes. But there is no genetic mechanism that adds a gene. (Mutations change an existing gene but never add a gene.) This means there is no mechanism for Darwinian Evolution and this is a fatal flaw in the Theory of Evolution."

What's that about?

Answer 1

There has been extensive horizontal gene transfer among the prokaryotes.

http://www.genome.org/cgi/content/abstra...

http://arjournals.annualreviews.org/doi/...

http://www.pnas.org/content/96/7/3801.ab...

There are also documented examples from eukaryotes, for example, rotifers add genes all the time:

http://scienceblogs.com/notrocketscience...

http://www.sciencemag.org/cgi/content/ab...

And of course the traditional routes of adding genetic information - sexual recombination, crossing over, and point mutations - provide overwhelming evidence of the genetic mechanisms that underlie evolution.

So when anyone tells you that there is no way genetic material can be added to an organism's genome, you can immediately be sure that this person has no clue, and has no business talking about something about which they are so clueless.....

Answer 2

>"But there is no genetic mechanism that adds a gene. "

Rubbish.   Anybody who says that to you that doesn't know diddly about genetics .. .and has apparently never heard of the kind of mutation called a gene duplication.

Gene duplications are covered in any Genetics 101 class in college.   A gene duplication is where an error during DNA replication results one or more genes being duplicated on the same or a different chromosome.   This may or may not involve errors in that copying ... but in any case, even if the new gene is an exact duplicate of the original gene, this new duplicate can undergo some other mutation ... perhaps hundreds of generations later ... that changes the properties of the resulting protein ... thus becoming a "new gene."

Our three-color vision is a result of such a gene duplication followed by a point mutation.   All primates have the same two photopigments (proteins that respond to light) ... but sometime after the split between the Old World primates (humans, apes, and the African and Asian monkeys) and the New World primates (the Central and S. American monkeys) one of those two pigments underwent a gene duplication followed many generations later by a point mutation that altered the wavelength sensitivity ... which took us from two-color vision to three-color vision.   In other words, this took us from two genes for photopigments to three genes.  This is why the primates on one side of the Atlantic (including humans) have three-color vision and the ones on the West side of the Atlantic have two-color vision.

So apparently the person who wrote that forward you got hasn't taken even a *basic* Genetics 101 course!

Answer 3

well idk about not being able to add genes but if thats a biologist speaking then i guess they know what they are talking about and it does make sense.

Answer 4

To add to what secretsauce said(and he is 100% correct),  the copy can freely acquire any non-functional mutations because there is a backup gene to produce that protein.  This will go on until the copy is able to produce a new functional beneficial protein, then natural selection locks it in place.  Voila!  A new gene.