Changes

The second objection relies on incidents of [[irreducible complexity]] and [[specified complexity]] to point to the unlikelihood that all life forms diversified through variation and selection alone.  They point to issues such as:

The second objection relies on incidents of [[irreducible complexity]] and [[specified complexity]] to point to the unlikelihood that all life forms diversified through variation and selection alone.  They point to issues such as:

* The transition from non-self-reproducing chemicals to self-replicating cells: the process of self-replication requires an enormous number of components be present in the cell for it to function at all, and none of the components required for self-replication serve any purpose unless all are present simultaneously; therefore it is unreasonable to conclude that [[abiogenesis]] occured without [[design]].

* The transition from non-self-reproducing chemicals to self-replicating cells: the process of self-replication requires an enormous number of components be present in the cell for it to function at all, and none of the components required for self-replication serve any purpose unless all are present simultaneously; therefore it is unreasonable to conclude that [[abiogenesis]] occurred without [[design]].

* The transition from asexual reproduction to sexual reproduction: male reproductive organs are incredibly complex, and serve no purpose unless female reproductive organs (which are equally, if not more, complex) already exist.  Therefore the sexes could not have evolved in a step-wise fashion, because neither set of reproductive organs would serve any purpose unless the other set already existed.

* The transition from asexual reproduction to sexual reproduction: male reproductive organs are incredibly complex, and serve no purpose unless female reproductive organs (which are equally, if not more, complex) already exist.  Therefore the sexes could not have evolved in a step-wise fashion, because neither set of reproductive organs would serve any purpose unless the other set already existed.

==== Criticism ====

==== Criticism ====

Evolutionists gloss over two important facts when making this argument: First, many retroviruses can infect both humans and apes.  The most notable of these is [[HIV]], which is widely believed to have originated as [[SIV]] in chimpanzees, but can also infect humans, apes, and monkeys.<ref>http://news.bbc.co.uk/1/hi/health/5012268.stm</ref>  It is entirely possible, therefore, that humans and apes were ''independently infected'' with the same virus.  Second, some retroviruses have been shown to have highly targetted insertion points, meaning that the virus selects very specific segments of the genome for insertion.<ref>Citation: (2004) Retroviral Gene Vectors Show Clear Target Preferences. PLoS Biol 2(12): e443 doi:10.1371/journal.pbio.0020443 [http://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.0020443&ct=1]</ref>  Consequently, it is entirely possible that the same virus infected both humans and apes, and targetted the same location.  This seems especially plausible in light of the fact that humans and apes have ''tens of thousands'' of endogenous retroviruses in their respective genomes -- at least a ''few'' of the retroviruses are likely to infect both humans and apes at the same location.

Evolutionists gloss over two important facts when making this argument: First, many retroviruses can infect both humans and apes.  The most notable of these is [[HIV]], which is widely believed to have originated as [[SIV]] in chimpanzees, but can also infect humans, apes, and monkeys.<ref>http://news.bbc.co.uk/1/hi/health/5012268.stm</ref>  It is entirely possible, therefore, that humans and apes were ''independently infected'' with the same virus.  Second, some retroviruses have been shown to have highly targeted insertion points, meaning that the virus selects very specific segments of the genome for insertion.<ref>Citation: (2004) Retroviral Gene Vectors Show Clear Target Preferences. PLoS Biol 2(12): e443 doi:10.1371/journal.pbio.0020443 [http://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.0020443&ct=1]</ref>  Consequently, it is entirely possible that the same virus infected both humans and apes, and targeted the same location.  This seems especially plausible in light of the fact that humans and apes have ''tens of thousands'' of endogenous retroviruses in their respective genomes -- at least a ''few'' of the retroviruses are likely to infect both humans and apes at the same location.

Additionally, scientists have determined that some endogenous retroviruses are indispensible to a species' life or reproduction.<ref>"Researchers Discover that Sheep Need Retroviruses for Reproduction," Texas A&M AgNews, 11 Sep 06.[http://agnews.tamu.edu/dailynews/stories/ANSC/Sep1106b.htm]</ref>  If the retrovirus is advantageous in some way, that would explain how the retrovirus spread to the entire species.  It also presents the possibility that retroviruses were used as part of the creative process, as [[retrovirus]]es are often used in genetic engineering today, to introduce new genetic material to cells.

Additionally, scientists have determined that some endogenous retroviruses are indispensable to a species' life or reproduction.<ref>"Researchers Discover that Sheep Need Retroviruses for Reproduction," Texas A&M AgNews, 11 Sep 06.[http://agnews.tamu.edu/dailynews/stories/ANSC/Sep1106b.htm]</ref>  If the retrovirus is advantageous in some way, that would explain how the retrovirus spread to the entire species.  It also presents the possibility that retroviruses were used as part of the creative process, as [[retrovirus]]es are often used in genetic engineering today, to introduce new genetic material to cells.

=== Common DNA-based genes in diverse species ===

=== Common DNA-based genes in diverse species ===