Do humans have amoeba DNA inside their bodies?

Pablo asks:

Quoted message said:

If yes, could humans become amoebas again in a few
million years?

No.

Wirt Atmar

On Sat, 29 May 2004 23:42:16 +0000 (UTC), [email hidden]

(Pablo Rena) said:

If yes, could humans become amoebas again in a few
million years?

Assuming this really is a serious question ----

Humans do not have amoeba DNA. Humans and amoebas are both
modern species that have a common ancestor in some very
ancient early eukaryotic cell, some billion or more years
ago. All eukaryotes share a number of genes, although they
have been highly modified in all lines in the billion years
intervening.

No, humans will not turn into amoebas. There is an
interesting human cell line called HeLa which has taken on
sort of a life of its own and could possibly be considered a
reversion of human genes to be expressed in single cell
form. However, that is a highly artificial system.

"Pablo Rena" <[email hidden]> wrote in message

Quoted message said:

If yes, could humans become amoebas again in a few
million years?

There was a thread a while back about whether HeLa cells (a
line of immortal cancer cells taken from a lady called
Henrietta Lacks) qualify as a new species.

A mutant version could conceivably live independently of the
lab, in which case it would be hard to deny it that title.

There are two answers to your question. Firstly we share
some DNA with the common ancestor of ourselves and amoebas.
These include things like histones - highly conserved
proteins which wrap DNA - and mitochondrial genes,
mitochondria are very basic in energy metabolism. Secondly,
there is very occasionally "horizontal transfer" of genetic
material from one species to another. There's no reason why
a gene from an amoeba could not accidentally get into the
human germ line. However this would not turn us into
amoebas, just give us one gene (just as adding a gene for
herbicide resistance to soya plants doesn't do anything
noticeable to the beans).