Reptile & Amphibian Forums

A few weeks ago there was a discussion on the differences between a group of frogs and whether or not what species it is. I hope people don't get confused about all of this (liger, mules,etc.). Taxonomy is not some hard rule that everything fits in stone. All it does is makes relationships so that we can put things where we think they belong. Even with the genetic work, as I suggested, it is still difficult to define what makes something a species. I think that the best way to go about things is to think about different species in terms of isolation. Sure, tigers can breed with lions and eventually produce viable offspring; however, these two animals are from completely different geographic areas. Maybe they recently branched off several hundreds of years ago and that is why they can interbreed...they still have those common forms of genes. At any rate, with the taxonomy of many thumbnail species....we may just be witnessing the same thing...Branching off. Maybe it's mimicry as Schulte has suggested.
Either way it is still fascinating to see the different morphological characteristics of every species or even individual for that matter. These are just some thoughts on the matter. What are your ideas? Am I reaching too far out there? Should we just lump all darts from one geographic region together and say that they should deserve the same protection and classification by trade organizations (CITES)? Just some thoughts sorry for the rambling.
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Justin
stk18119@loki.stockton.edu

D.auratus
D.leucomelas
D.tinctorius (lorenzo, yellowback, citro, pb, oyopock,etc.)
D.azureus
D.ventrimaculatus (yellow/gold)
D.pumilio (blue jeans, solid red)
P.aurotaenia (narrow bands/green)
P.bicolor
E.tricolor (Santa Isabel)
H. leucophyllata
P. hypochondrialis azurea
P. resinfictrix
etc.......

Justin,
Hi, you and I had a little exchange on F1,F2 on another post.
At what point does CB frogs become a subspecie (or start the drift) from its wild counterpart (due to isolation)? I would think that traits in CB frogs that can be carried on due to human and environmental controls may not be allowed to happen in the wild. At what point would it be so domestic that it couldn't survive in the orignal environ. How broad or narrow is the traits that makes the given frog its specie? How fast does environment cause change? What are the most influential varibles?
I'm no expert, I'm just tossing thoughts onto the table.

Hello again.
Man you are a curious fellow and have some interesting ideas. I never really thought much about selective breeding in captive populations. Technically, they are isolated and could eventually, over many years (most likely decades- if not centuries), become so genetically different that we may end up with captive individuals that may not be able to interbreed with wild populations. In theory it could work. However, we are just emphasizing traits that already exist. This is the problem in modern day evolutionary thought. How long would it take? There would have to be some sort of random event (mutation? hybridization?) CB population- that’s right population because speciation technically doesn’t go by individuals. So we would have to have a pretty large captive population. Case in point, many domesticated breeds of dogs came from their wolf ancestors and human interaction- through selective breeding- has made most of the variation in breeds we see today; however, domesticated dogs can still breed with wild wolves and produce viable offspring.

It has been in my experience that frogs are very instinctive and I would think that many captive individuals would be able to still survive in the wild; however, with darts this may not be the case just due to the toxins derived from the food chain. CB individuals are no longer toxic (after many generations) and would probably be picked off easily by predators once released. However, this is all speculation. There is no general rule when trying to tell how fast speciation occurs (mostly speculative) and many environmental factors come into play. Geographical barriers such as, mountains, oceans, and rivers are all features that can act as barriers. Once a new area is colonized by a species and they become divided from the original population than it allows for new traits to develop because there is no genetic inflow…. This seems to be the case for all of the tinctorius color morphs we see. Selective pressures such as, competition and predation can also play as factors that can drive traits to change over time.

Generally, a combination of morphological and behavioral traits are what researchers look for when trying to decide between species. However, most will agree that reproductive isolation is the delineating factor.

Ugh! This is long. Hope I answered at least one question.

Hope that helps.
-----
Justin
stk18119@loki.stockton.edu

D.auratus
D.leucomelas
D.tinctorius (lorenzo, yellowback, citro, pb, oyopock,etc.)
D.azureus
D.ventrimaculatus (yellow/gold)
D.pumilio (blue jeans, solid red)
P.aurotaenia (narrow bands/green)
P.bicolor
E.tricolor (Santa Isabel)
H. leucophyllata
P. hypochondrialis azurea
P. resinfictrix
etc.......