54

Firstly, it's not true that you can't tell racial background from DNA. You most certainly can; it's quite possible to give fairly accurate phenotypic reconstruction of the features we choose as racial markers from DNA samples alone and also possible to identify real geographic ancestral populations from suitable markers. The reason that human races aren't ...


37

Well, that's just it, we don't actually have much phenotypic variation. For example, compare this: to this: or this: Or this: to this: This is phenotypic variation: So, as I hope is clear from the images above, phenotypic variation among humans is tiny compared to other species. We just notice small differences much more because, well, it's us so ...


25

The concept you are referring to is speciation and it has been well studied in a wide variety of different natural organisms. I suppose here we are talking about the biological species concept. The overall answer is yes it is possible, but critically depends on a few different factors. The reality of speciation in the wild is very complex, but these are some ...


16

I decided to summarize a competing hypothesis to make our answers more balanced. I also tried to address the question about the degree of human morphological diversity compared to other animals. According to Woodley (2010), it is plausible that H. sapiens does not belong to one species and subspecies (i.e. is polytypic). Some of the data he uses to support ...


12

Bias When you say phenotype you mostly mean "skin color", "size of the nose", "hair color", "shape of the eyes", "height", and some others. All these traits that we manage to find to explain population structure among humans. But you forget all the rest of the phenotypic diversity. If you would choose 1000 randomly chosen traits (external morphology and ...


10

It seems to me that many answers to this question suffer from the nasty habit of "political correctness". As a zoologist, I never heard of somebody sequencing the whole DNA of any species to decide when to use or not the term "race". If a group of animals comes from a side of a river, and the other comes from the other side, and they have one or a few ...


10

Two different species can have the same species epithet if they belong to different genera ('species name' is referring to the full binomial name). Consider for example Pinus glabra and Ilex glabra P. glabra I. glabra Two species can be have the same genus name (meaning they belong to the same genus) and will therefore necessarily have different species ...


9

Introduction to phylogeny What makes that two species being closely related or not has nothing to do with whether they look a like or whether they live in similar environment. It has to do with their evolutionary history. Evolutionary history used to be inferred from phenotypic traits ('phenotype'≈'how an individual looks like') but today it is most often ...


9

You can certainly refer to short peptides by their sequence. I don't know of any exact boundaries, but I've seen tripeptides referred to by either their three letter codes (Ala-Asp-Asn) or even the chemical name (alanylaspartylasparagine) although obviously that gets ridiculous pretty quickly. As the largest known protein, titin also has the longest IUPAC ...


9

They are either treated or even declared to be synonyms in all the texts using both of the terms that I have ever read. Just one reference: the nearest Flora on my desk, G. Marconi, F. Corbetta, Flora della Pianura Padana e dell'Appennino Settentrionale, uses the notation Compositae = Asteraceae. It is worth to note that Compositae, 'composite ones' in ...


8

I know nothing about lizards, but this looks like a Carolina anole (Anolis carolinensis), also known as a green anole. Apparently they can change colour:


8

Short answer Sedges have edges, and they're in different families. See Minnesota Wildflowers for a great summary with images. Long answer Both are in the order Poales, but they are in different families: Grasses = Poaceae (of the graminid clade) Sedges = Cyperaceae (of the [non-monophyletic]1 cypirid lineage) Some anatomical differences: Compiled ...


7

Creep is correct. I sent an email asking this question to The Tortoise Group, which is a non-profit organization whose mission statement is: Improving the lives of wild and desert tortoises through education. The Executive Director replied: It's a bale for turtles and a creep for tortoises. I am sure they could have come up with a better name! If you ...


7

In biradial symmetry, in addition to antero-posterior axis there are also two other axes or planes of symmetry at right angles to it and each other such as the sagittal or median verticular-longitudinal and transverse or cross axes. Such animals have two pairs of symmetrical slides i.e there are two planes of symmetry. You can visualize it as a combination ...


7

Again, I would say: no, genus is not enough. Another example: boletes (specifically, genus Boletus). According to Wilderness College: One of the most common and well-known groups of edible wild mushrooms are the boletes or boletus species (Boletaceae) ... But Many species in this group are edible, with only a handful being poisonous. The poisonous ...


7

The NCBI Taxonomy staff places square brackets around the genus for some species (examples: [Bacillus] aminovorans, [Candida] auris) to indicate that they are misclassified*, meaning placed incorrectly in a higher taxonomic rank. References: https://support.nlm.nih.gov/knowledgebase/article/KA-03379/en-us


6

If you keep reading the next sentence it makes clear what is meant (emphasis mine): Crocodiles (subfamily Crocodylinae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. Crocodylinae, all of whose members are considered true crocodiles, is classified as a biological subfamily. A ...


6

The path is correct. The safest reading is to say that the lion shares a set of characteristics with the lungfish. You can also say that lion and carps are bony vertebrates (Euteleostomes). In evolutionary taxonomy, each taxon does not need to consist of a single ancestral node and all its descendants: it allows for groups to be excluded from their parent ...


6

I do not believe it will happen. There are multiple roadblocks: First, speciation time is measured in generations, not years. The human generation time is long, the 3000 generations mentioned in another answer for a fish translates to nearly 100,000 years. Are human populations not going to interbreed over a time span that long? Second, the speed of ...


5

This is a widespread issue amongst binomial names. Only the full binomial name has to be unique in nomenclature, and therefore many genera contain different organisms with the same specific epithet. As Remi.b has already mentioned, two organisms with binomial names that have the same species but different genus are very likely more different from each other ...


5

A taxon (plural taxa) is any taxonomic unit. For example, the class Mammalia is a taxon which includes all mammalian species. Similarly, a species is a taxon, Panthera tigris being the tiger. This taxon contains lower taxa, which are sub-species, such as Panthera tigris tigris (Bengal tiger) or Panthera tigris sumatrae (Sumatran tiger). Rank is simply the ...


5

It is natural to be confused because the consensus has changed over the years and is still not settled. In part this is because knowledge has been gained but remains incomplete, and in part it is a matter of opinion and aesthetics about what is best for usefulness at various levels of detail and understanding. The system put forth in the textbook seems to ...


5

It seems like the simple version of your question is: can anyone come up with even one example of 2 fungi species in the same genus in which one is edible and the other is not? Here's one example: The genus Amanita. This genus contains about 600 species and contains some very toxic species -- in fact, it's often considered one of the most deadly genera ...


5

In earlier days, biological classification systems were often described as artifical or natural, with natural systems reflecting the 'real' relationships among living beings, and artificial ones allowing classification only for some limited purpose (Gilmour, 1937). Natural systems were supposed to be based on a large number of characters, with a focus on ...


5

granulocytes are a type of leukocytes that have granules (hence the name) visible by microscopy Yep, that's it; like you said, that's where they get the name: their appearance. Not their function or progenitor, just their appearance, and they were named long before the other factors were understood. That history goes back to at least the mid 1800s: Paul ...


4

What I found was that creep is a collective noun. The professor Peter Trudgill uses the word in a chapter about collective nouns and the example is of tortoises. I don't know what book to tell you to look in though. He is professor of sociolinguistics. From a search on collective nouns for animals, turtles, and reptiles, I only found turtles having the ...


4

You can find discussions of problems with rank-based taxonomy in light of phylogenetics in Ereshefsky 1994, de Queiroz 1996 and Ereshefsky 2002. To summarize, the main problems they identify are: It's hard to define what exactly an "order", "family" or "genus" is; in particular, taxa at the same rank aren't always comparable. For example, order Hymenoptera, ...


4

It is generally accepted now that Chlorophyta are Plantae (see here). They are more closely related to plants than any other group of organism. Protist is a kind of basket term for any eukaryotic unicellular organism that is not an animal, fungi or a plant which is a rather exclusionary definition. Personally, I think the kingdoms are pretty 'macro' ...


4

The scientific name (better known as latin name or binomial name) of a species is unique to this species. No two species can have the same latin name. Also, a single species cannot have two different latin names. But of course, mistakes happen and we don't seem to bother too much about them (esp. when the two species are very unrelated; see What instances ...


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