# Evolution/Speciation Question **URL:** \ **Category:** Factual Questions\ **Created:** [February 2, 2005, 9:01pm UTC](https://boards.straightdope.com/t/evolution-speciation-question/288042 "2005-02-02T21:01:57Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Ephemera](https://avatars.discourse-cdn.com/v4/letter/e/8baadc/32.png) [@Ephemera](https://boards.straightdope.com/u/Ephemera)\ **Post date:** [February 2, 2005, 9:01pm UTC](https://boards.straightdope.com/t/evolution-speciation-question/288042/1 "2005-02-02T21:01:57Z")
Christian fundamentalists with a poor grasp of what evolution really is sometimes argue that “if man came from monkeys, why do monkeys still exist?” with the correct answer being that man didn’t come from monkeys; he came from a common ancestor that speciated, creating new species that were more suited to their environments with the parent species then withering away. But is that always the case? Are the parent species in speciation always doomed to extinction in favor of their daughters? Are there any cases that we know of where a distinct species branched off from the old one and they have both survived and flourished? A subspecies that became a full species in its own right without any harm to its parent, so to speak? Domestic animals such as dogs are an example, I suppose, but not really what I am looking for as they can still interbreed with wolves perfectly well. ---
**Author:** ![rjk](https://avatars.discourse-cdn.com/v4/letter/r/ed655f/32.png) [@rjk](https://boards.straightdope.com/u/rjk)\ **Post date:** [February 2, 2005, 9:09pm UTC](https://boards.straightdope.com/t/evolution-speciation-question/288042/2 "2005-02-02T21:09:34Z")
Darwin’s finches? Both species surviving should be fairly common. One branch stays where it started, while a sub-group wanders off to a new environment. Extinction of the old species would depend on the new one staying around. ---
**Author:** ![rjk](https://avatars.discourse-cdn.com/v4/letter/r/ed655f/32.png) [@rjk](https://boards.straightdope.com/u/rjk)\ **Post date:** [February 2, 2005, 9:42pm UTC](https://boards.straightdope.com/t/evolution-speciation-question/288042/3 "2005-02-02T21:42:41Z")
That was a little incoherent, I think. I still stand by Darwin’s finches, though! Survival of both old and new species (or splitting into two or more new ones) is pretty common. [This Google search](http://images.google.com/images?q=Phylogenetic%20tree&hl=en&lr=&c2coff=1&sa=N&tab=wi) gives links to various “phylogenetic trees” showing the evolutionary relationships among living things. Look in [Wikipedia](http://en.wikipedia.org/wiki/Phylogenetic_tree) for an article and more links. Each branch is a case of one species becoming two or more, and both surviving for a while. Mutual survival probably happens when the new species is somehow not competing directly with the original, maybe by moving on geographically or by evolving new habits. You might also search for “punctuated equilibrium” to see a proposed explanation of how speciation might happen. ---
**Author:** ![newcomb\_being](https://avatars.discourse-cdn.com/v4/letter/n/97f17d/32.png) [@newcomb\_being](https://boards.straightdope.com/u/newcomb_being)\ **Post date:** [February 2, 2005, 9:49pm UTC](https://boards.straightdope.com/t/evolution-speciation-question/288042/4 "2005-02-02T21:49:53Z")
Well, chimps are still around aren’t they? ---
**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:** [February 2, 2005, 10:20pm UTC](https://boards.straightdope.com/t/evolution-speciation-question/288042/5 "2005-02-02T22:20:52Z")
> [@Aesiron](#): > > But is that always the case? Are the parent species in speciation always doomed to extinction in favor of their daughters? Are there any cases that we know of where a distinct species branched off from the old one and they have both survived and flourished? A subspecies that became a full species in its own right without any harm to its parent, so to speak? There are three “methods”, so to speak, whereby speciation occurs: **1. Allopatric Speciation** This is when species form as the result of a subpopulation (or “daughter population”) becoming isolated from the main (or “parent”) population. This is considered to be one of the main form of speciation, creating two non-interacting populations which are then free to vary more-or-less independently. This is how the branches on evolutionary trees are formed. **2. Parapatric Speciation** This is a form of allopatric speciation which can occur n the absence of a geographical boundary. Essentially, if a population is large enough, individuals from one “end” might not interact with individuals at the other. Or, put another way, if a population occupies a vast area, but individuals only disperse over a restricted area within that region, then subpopulations can form, and subsequetly vary independently of other subpopulations – gene flow between subpopulations is restriced. It is theorized that much of the diversity in the Amazon Basin is the result of parapatric speciation. Note also that simply great distances between subpopulations, even with no intervening barriers, can result in parapatric speciation. **3. Sympatric Speciation** This is when two or more subpopulations form from a parent population within the same geographical area. It is largely considered theoritical, at best, though there are some instances which might be attributable to sympatric speciation (three-spined sticklebacks being one possibility). Note also that a given population may also slowly change over time, as the environment changes. In such instances, the population will become adapted to the new environments, as the “better adapted” forms slowly replace the “not so well adapted” forms. This is very likely what many creationists cling to as the primary mode of speciation, though in this case, the speciation is more temporal than geographical (that is, the parent and daughter species do not occupy the same time period, even though the daughter(s) may remain in the same geographical area). ---
**Author:** ![Ephemera](https://avatars.discourse-cdn.com/v4/letter/e/8baadc/32.png) [@Ephemera](https://boards.straightdope.com/u/Ephemera)\ **Post date:** [February 2, 2005, 10:20pm UTC](https://boards.straightdope.com/t/evolution-speciation-question/288042/6 "2005-02-02T22:20:52Z")
Chimpanzees and humans evolved from a common ancestor and are not what I’m looking for. Thanks for the leads, **rjk**.