Join for Free!
114500 members

Locus specificity and ERVs - Q from a creationist

Genetics as it applies to evolution, molecular biology, and medical aspects.

Moderator: BioTeam

Locus specificity and ERVs - Q from a creationist

Postby BarryDesborough » Sat Sep 07, 2013 2:49 pm

A question for geneticists -

How essential is it that a gene or other section of DNA that performs a useful function is at a particular locus? I ask, because I am discussing endogenous retroviruses (ERVs) with an evolution-denier, who says that the ERVs that are apparently orthologous in, say, chimps and humans, are there because they infected both species independently and were fixed by positive selection pressure. IOW, selection pressure acted as a 'sieve', retaining only the ERVs that served an adaptive function. (We cannot say that not all ERVs serve an adaptive function - it may be that we just haven't discovered what adaptive functions they serve.) The reasoning fails if the adaptive functions do not depend on their exact loci.
Posts: 1
Joined: Sat Sep 07, 2013 1:14 pm

Postby Darby » Tue Sep 10, 2013 3:57 pm

The issue is whether there's an adaptive function. It seems like the adaptive function is non-expression, which might be affected by location, or might not. If the ERVs are in similar locations, that would imply that they entered the system in a shared ancestor...
Posts: 1262
Joined: Thu Mar 02, 2006 5:29 pm
Location: New York, USA

Postby JackBean » Fri Sep 13, 2013 11:16 am

it may just be they are not that negative to be selected out

Cis or trans? That's what matters.
User avatar
Inland Taipan
Inland Taipan
Posts: 5665
Joined: Mon Sep 14, 2009 7:12 pm

Re: Locus specificity and ERVs - Q from a creationist

Postby Cat » Sun Sep 15, 2013 4:08 pm

BarryDesborough wrote: The reasoning fails if the adaptive functions do not depend on their exact loci.

I don't really understand your reasoning. However, retroviruses are the major players and drivers of evolution. When they insert into host genome, they can alter host genes located at and around the insertion point - they can disrupt genes, activate genes, alter gene expression.
King Cobra
King Cobra
Posts: 625
Joined: Thu Feb 14, 2008 7:40 pm

Postby wildfunguy » Mon Sep 30, 2013 1:26 am

When they said that the reasoning fails if location doesn't matter, I think they were implying that these 'orthologous' (homologous) sequences are at the same loci in chimps and humans. The idea is that, with all the possible locations for this sequence, it is improbable that it would wind up in the same location within each species. If that is indeed the argument, I would suggest the possibility that similar location is due to the way the virus inserts its genetic material.
User avatar
Death Adder
Death Adder
Posts: 96
Joined: Sat Feb 18, 2012 4:28 am

Return to Genetics

Who is online

Users browsing this forum: No registered users and 2 guests