# Evolution question **URL:** \ **Category:** Factual Questions\ **Created:** [April 13, 2002, 11:05pm UTC](https://boards.straightdope.com/t/evolution-question/103493 "2002-04-13T23:05:51Z")\ **Posts on this page:** 5\ **Page:** 2
**Author:** ![Liberal](https://avatars.discourse-cdn.com/v4/letter/l/848f3c/32.png) [@Liberal](https://boards.straightdope.com/u/Liberal)\ **Post date:** [April 15, 2002, 10:41am UTC](https://boards.straightdope.com/t/evolution-question/103493/21 "2002-04-15T10:41:27Z")
> [@](#): > > you see evidence of evolved death-traits all the time, many spontaneous miscarriages are because the fetus is unfit. So, Ernst Haeckel was right? ---
**Author:** ![Sublight](https://avatars.discourse-cdn.com/v4/letter/s/439d5e/32.png) [@Sublight](https://boards.straightdope.com/u/Sublight)\ **Post date:** [April 15, 2002, 12:03pm UTC](https://boards.straightdope.com/t/evolution-question/103493/22 "2002-04-15T12:03:05Z")
If you mean Haeckel’s “ontogeny recapitulates philogeny,” then I would say no. Miscarriages due to genetic disorders are not, AFAIK, throwbacks to older, extinct forms, but rather are new changes that simply don’t work. ---
**Author:** ![LateComer](https://avatars.discourse-cdn.com/v4/letter/l/b5ac83/32.png) [@LateComer](https://boards.straightdope.com/u/LateComer)\ **Post date:** [April 15, 2002, 12:55pm UTC](https://boards.straightdope.com/t/evolution-question/103493/23 "2002-04-15T12:55:03Z")
Aren’t many species of parasite animals that have reduced their complexity due to their reliance on other organisms for some of their bodily functions? Tapeworms and such? ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [April 15, 2002, 5:09pm UTC](https://boards.straightdope.com/t/evolution-question/103493/24 "2002-04-15T17:09:07Z")
> [@](#): > > \*Originally posted by Sublight \* > \*\*If you mean Haeckel’s “ontogeny recapitulates philogeny,” then I would say no. Miscarriages due to genetic disorders are not, AFAIK, throwbacks to older, extinct forms, but rather are new changes that simply don’t work. \*\* Many are, I am sure, the result of non-genetic factors (e.g., health of the mother). ---
**Author:** ![Sublight](https://avatars.discourse-cdn.com/v4/letter/s/439d5e/32.png) [@Sublight](https://boards.straightdope.com/u/Sublight)\ **Post date:** [April 16, 2002, 1:27am UTC](https://boards.straightdope.com/t/evolution-question/103493/25 "2002-04-16T01:27:54Z")
True, most miscarriages are probably due to non-genetic factors. The ones that are genetic in nature, however, can’t really be described as steps “backward” as they are by Haeckel, whose “ontogeny recapitulates philogeny” principle states that a developing fetus passes through all the evolutionary stages of its ancestors before finally reaching the “highest” level as a fully-developed human (a white one, btw. Haeckel also considered non-whites to be lower evolutionary stages, thus the term “mongoloidism” (Down’s syndrome) for when a fetus failed to develop beyond the asian, or mongoloid stage). In his view, birth defects (and genetic-factor miscarriages) occurred when a fetus became stuck at a lower level of development. [Previous page](https://boards.straightdope.com/t/evolution-question/103493.md?page=1)