What do you anons think about the species concept? From a birth

>>8420203
>Its just a construct by humans so we can catagorise and understand life around us better, but from my understanding there really is no such thing as a species.
Well yeah but it's not like they group things together arbitrarily.

>>8420203
Speciation has a pretty rigid definition desu senpai

>>8420208
What is a definition of species that applies across all taxon?

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>>8420203
We define every concept. The fact that we defined it doesn't mean it doesn't exists. Just because we defined what species are, it means species exists.

>>8420220
Doesn't mean we're right tho
The fact that there are numerous inconsistencies in what particular taxonomists decide to be a species makes the whole concept false.
Like, its the best we've got to understand what's around us, but it's rarely questioned or challenged - which I think is dumb

>>8420222
There is no right or wrong way to group animals.
Every way to group them will be arbitral, it cannot be false.
No one question it because there is nothing to question. Scientists agreed that this is one of the ways you can group animals and use it when it's suitable.

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>>8420203

A species may be considered a population of individuals genetically sufficiently isolated from other populations. There are several criteria to classify individuals in one species or another, each of these criteria with the limitations that hinder the application of this definition.

There are two definitions of the species :

- Typological definition of species :

A species is defined by phenotypic criteria. We assume that within a species, individuals must look like each others and must not look like individuals of another species.
This is usually the case, but this definition has still several limitations: sexual dimorphism (within a species, a male individual may not look like at all to a female individual) or in the case of twins species (same appearance but different species).


- Biological definition of species :

This time, the criterion is the interfecondity. In this case, two individuals are of the same species if and only if they can interbreed and have fertile offspring. But again, several limitations appear. Some individuals of different species can mate and give birth to a hybrid and fertile individual. It is also complicated to apply this definition to organism extinct since millions of years because obviously we are unable to test the interfertility.

>>8420235
I understand this. Just like I could make up my own naming system for organisms. What I'm saying is that the whole idea of species being an exact science is fallible. The concept is crap

>>8420245
The amount of genetic difference required for a species to be described is not defined anywhere, and is up to taxonomists and the authorities on certain taxons discretion. It's just a certain persons opinion, that's why species are split and merged all the time.
And like you say, many, many species are capable of interbreeding.
So what is a species?
there is no clear cut definition.

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>>8420203
Fucking moron.

>>8420273
>I understand this. Just like I could make up my own naming system for organisms. What I'm saying is that the whole idea of species being an exact science is fallible. The concept is crap
That's philosophical problem and no one gives a fuck about it. Grouping species is a tool, it works and people use it. There is no point in changing or questioning something just because it doesn't fit some other arbitral definition.

>>8420203
The species concept is flawed, but it's the best we have. How I think to describe a species is it is the average or ideal of a range of genetic data that is in constant flux due to natural selection pressures with each individual within that range being able to successfully reproduce with others of similar genetic makeup.

For example, what you think of when you think of a rabbit is a range of many different genetic traits, from length of ears and feet, skeletal structure, fur color, body size, behavioral characteristics, etc. There are exceptions of course, as it's not a perfect idea, but when talking in a general sense of a "species" it's much easier and useful to think of it as a monolithic, frozen entity rather than something that is in a constant state of change and has pretty fuzzy delineations between other similar species.

>>8420203
They are there as a book keeping notation. The dewy decimal system doesn't denote anything really but we still use it to categorize all of our libraries. It may be arbitrary but it's useful for when one needs to identify a snake or animal for a study and/or antivenom. It's been arbitrary since day one, phylogenetics makes it easier to produce a probabilistic tree that can be used to infer the likelihood that two things had an ancestor x number of generations ago using molecular clocks.

tl;dr it's book keeping, not something actually exists.

>>8420203
To me it comes down to what can copulate and produce offspring.

Many different species of dogs can reproduce with one another. Dogs, however, can not get a human woman pregnant even if they fuck them for hours and cum in them.

>>8420203
i think the phylogenetic way we clasify species is good though we have many empirical barriers. theoretically there are obviously many problems though. i think though most biologists must be aware of these issues and the phylogenetic classification is more of a pragmatic matter to make further inferences of adaptation, the process of evolution and such. though it is good to keep catalogues of animals. luckily we dont have access to every single fossil of every single animal, otherwise we wouldnt be able to classify anyting

>>8421885
I'm glad you think about dogs fucking chicks for hours and cumming inside them.

The best definition of species is a monophyletic group of populations that evolve as a unit. In practice it's difficult to use this definition, so the biological definition >>8420245 is used instead.

>>8420208
It has literally dozens of definitions you stupid undergrad pleb.

Bacteria are considered living organisms and we define a species of bacteria by just looking if more or less than 95% of the DNA is the same. If it is, it's the same species. If it's not, it's not.

This illustrates how fluid our species concepts really are and how little they actually mean.

Even the biological species concept is pretty retarded.

>>8420203
Useful in that there are relatively discrete clusters, even though it's ultimately actually a spectrum made of spectrums.

Every organism is just a point in an otherwise mechanical waterfall. Many of these points cluster close together.

>>8420203
Humans are so weird we have so many subspecies that it breaks our own rule.

its completely made up to make ourselves feel comfortable with the enormity and randomness of life - humans are inherently autistic to some degree and want everything to be categorized in nice little boxes.

further down the rabbithole we realise its all bullshit.

>but anon, muh inability to interbreed
shut the fuck up undergrad

>>8425300
16s/18s phylogeny has really overtaken whole-genome identity in terms of species identity.