Basically what I'm asking is if an animal of species x were to lay an egg, and the animal inside that egg happened to be the first member of a genetically new species y, would the egg be considered an x egg or y egg?

  • $\begingroup$ Parent species is certainly what they'll call it, unless there was some reason to check the genetics. $\endgroup$ – The Nate Jan 9 '16 at 2:57
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    $\begingroup$ What you are proposing does not happen in higher Eukaryotic organisms. See UC Berkley site on Speciation for more detail. $\endgroup$ – AMR Jan 9 '16 at 3:09
  • $\begingroup$ Asap Science answer to this question $\endgroup$ – Remi.b Jan 12 '16 at 5:41

Wow, interesting theoretical question. If scientists compared the parent's genes to the hatchling's genes and decided they're sufficiently different to merit their designation as distinct species, then I imagine they would give the young its own scientific name.

But it's hard to imagine such an event happening. New species generally evolve gradually over long periods of time, and the odds against finding a magic dividing line between species x and species y are very remote.

If you compare species x with a descendant living 10,000 years later, you might be able to see a distinct difference. But speciation in one generation is something that would just be awfully hard to measure.


Species are generally defined in terms of populations (see e.g. the wikipedia page), and it is therefore relatively meaningless to talk about individuals as species. That species is defined in terms of populations is true for many species concepts, e.g. as groups that can produce fertile offspring (biological species concept) or as a evolutionary distinct lineage (phylogenetic species concept). The question is therefore somewhat ill-posed, since it is only framed in terms of individual parents and offspring.

A possible exception could be speciation in apomictic species or speciation events following a change in ploidy level, but this is mostly relevant for certain types of asexual species and probably not what you are after since you are talking about egg-laying animals.



An Ostrich egg. A chicken egg. A quail egg...whether you call an egg based on who laid it or who is inside of it is not a question of science but a question of linguistic.

Non-fertilized chicken eggs do not contain any chicken. We still call these eggs chicken eggs. Following the same logic, I would call an egg based on who laid it. But really this has nothing to do with science.

But, the first question one should ask is whether the scenario you are describing makes any sense. Is it possible for an offspring to be of a different species than its parent?

Can the offspring belong to a different species than the parent?

The concept of species is very poorly defined. The reason is not that we fail to agree on a definition but that the categorization of living things into discrete categories often does not make sense.

Let's think of an individual of species A. Imagine we were to look back at the ancestry of this individual for a relatively high number of generations. You chose one specific ancestor in the lineage and realize that this ancestor looks very different. Maybe we have already named the species that this individual belongs to. Let's say the ancestor belongs to species B. So, at some point there was necessarily an individual from species B who had an offspring who belonged to species A, right? ...not really. The reason is that the concept of species makes little sense. There is no such thing as absolutely clearly defined groups of individuals that you can gather into one single species.

You should read this post on the concept of species and then read this post on species ring and come back here once you finished reading....

We often think of the concept of ring species when thinking about population separated spatially. But the same concept hold true for population separated temporally. If we come back to the two individuals belonging to species A and species B. These two individuals probably cannot reproduce together and are very different. It seems legitimate to classify them in different species. However, all individuals along the way were probably able to reproduce with their own parent and offspring.

  • $\begingroup$ This is really convoluted. The simple answer is that unless giving birth to a hybrid, a species will only produce offspring of that species. $\endgroup$ – AMR Jan 9 '16 at 4:40
  • $\begingroup$ Hidden behind your simple answer is hidden the conceptual issue of the species. Saying it is impossible to give birth to an individual belonging to a new species (except hybridization) seems to contradict the existence of speciation events. $\endgroup$ – Remi.b Jan 9 '16 at 4:50
  • $\begingroup$ What are you talking about? $\endgroup$ – AMR Jan 9 '16 at 4:59
  • $\begingroup$ Well... that is a broad question that you are asking @AMR! Saying a species will only produce offspring of that species is contradictory to a species can evolve to become another one and the reason is that the term species is poorly defined. $\endgroup$ – Remi.b Jan 9 '16 at 23:34
  • $\begingroup$ In a single generation an organism of a defined species will not give birth to another species, unless the mating is between two individuals of such compatibility as they can produce a hybrid, and more often than not, in those situations the hybrids are sterile. Any single generation will not be that different from the prior one or the next one. It is over time and gene pool separation that different species can be distinguished when making a comparison. So it is not contradictory. $\endgroup$ – AMR Jan 10 '16 at 0:02

This question is interesting. First of all, I recommend you to look a little bit about the most popular definitions of species and, more importantly, how speciation can occur.

I can picture a problem of hybridization when I think of your question. Since speciation takes many (plentiful) generations to happen, and as I can remember, can involve sympatric speciaton and/or extinction of the parent's species since the new one won't be enormously different in matters of food request, habitat and other physiological needs (generally) and so there will be a conquest/fight for resources (you can look out for more details in Charles Darwin's On the Origin of Species). All this to say you won't have a newton coming out of a frog's egg. :)

But hybridization can lead to speciation, and you can have a hybrid coming out of an egg of a well descripted species. This happens with more frequency in fishes, insects and amphibians. For example, you can study individuals that are phenotipically different from their parents, with other types of adaptation (sometimes better) to the environment, and that emerge from different (and phylogenetically proximate) diploid sexually reproducing species... and the resulting individuals can have, of course, di/tri/tetraploid genomes... So, morphological and genetically different from their parents!!

And when referring to these situations, scientists generally call them genus name of the species involved + complex. For ex, the Pelophylax complex, involving 3 types of frogs.

If you really have an urge to search about this, try to go to this paper.
Hope I helped.

PS: You can also research about the Squalius alburnoides complex, which is about a group fishes extant in the Iberian Peninsula, with an amazing (and complex) process of speciation where you have a well characterized hybrid coming out of eggs layed by hybrids or parent species.


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